Fundamentals of human anatomy and physiology.

Anatomy(Greek anatomё - dissection, dismemberment) - a science that studies the shape and structure of the human body (and its constituent organs and systems) and explores the patterns of development of this structure in connection with the function and surrounding the body environment.

Physiology- the science of life processes and the mechanisms of their regulation in cells, tissues, organs, organ systems and the whole human body.

All living things are characterized by four features: growth, metabolism, irritability and the ability to reproduce themselves. The combination of these features is characteristic only of living organisms. The structural and functional unit of living things is the cell.

Cell - it is a structural and functional unit of a living organism, capable of division and exchange with the environment. It carries out the transfer of genetic information by self-reproduction. Cells are very diverse in structure, function, shape, and size (Fig. 1). The latter range from 5 to 200 microns. The largest in the human body are the egg and nerve cell, and the smallest are blood lymphocytes.

Thus, the human body is a collection of cells. Their number reaches several billion. The cell, as part of a multicellular organism, performs the main function: the assimilation of incoming substances and their breakdown with the formation of energy,

Rice. one. cell shapes:

1 - nervous; 2 - epithelial; 3 - connective tissue;

4 - smooth muscle; 5- erythrocyte; 6- sperm; 7 -egg

necessary to keep the body alive. The cell is part of the tissue that makes up the body of humans and animals.

Textile - it is a system of cells and extracellular structures united by the unity of origin, structure and functions. As a result of the interaction of the organism with the external environment, which has developed in the process of evolution, four types of tissues have appeared with certain functional features: epithelial, connective, muscular and nervous, each of which consists of many cells of the same type and intercellular substance. Each organ is made up of various tissues that are closely related. Connective tissue many organs forms a stroma, and the epithelial - the parenchyma. The function of the digestive system cannot be fully performed if its muscular activity is impaired.

Thus, the various tissues that make up a particular organ ensure the performance of the main function of this organ.

epithelial tissue covers the entire outer surface of the human body and lines the mucous membranes of hollow internal organs (stomach, intestines, urinary tract, pleura, pericardium, peritoneum) and is part of the endocrine glands.

Connective tissue according to its properties, it unites a significant group of tissues: connective tissues proper; tissues that have special properties (adipose, reticular); skeletal solid (bone and cartilage) and liquid (blood, lymph). Connective tissue performs supporting, protective (mechanical), shaping, plastic and trophic functions. This tissue consists of many cells and intercellular substance, which contains a variety of fibers (collagen, elastic).

Muscle ensures the movement of the body in space, its posture and the contractile activity of internal organs. Muscle tissue has such functional features as excitability, conductivity and contractility. There are three types of muscles: skeletal (striated, or voluntary), smooth (visceral, or involuntary) and cardiac muscle.

All skeletal muscles composed of striated muscle tissue. Their main structural and functional elements are muscle fibers (myofibrils), which have a transverse striation. Muscle contraction occurs at the will of a person, therefore such muscles are called arbitrary muscles. Smooth muscles consist of spindle-shaped mononuclear cells with fibrils devoid of transverse bands. These muscles act slowly and contract involuntarily. They line the walls of internal organs (except the heart). Thanks to their synchronous action, food is pushed through the digestive system, urine is excreted from the body, blood flow and blood pressure are regulated. cardiac muscle forms the muscle tissue of the myocardium (the middle layer of the heart) and is built from cells whose contractile fibrils have a transverse striation. It has a very good blood supply and is significantly less fatigued than normal striated tissue. The structural unit of the muscle tissue of the heart is cardiomyocyte. The contraction of the heart muscle does not depend on the will of the person.

nervous tissue is the main component of the nervous system, ensures the transmission of signals (impulses) to the brain, their conduction and synthesis, establishes the relationship of the body with the external environment, participates in the coordination of functions within the body, ensures its integrity. It is characterized by the maximum development of such properties as irritability and conductivity. Irritability- the ability to respond to physical (heat, cold, light, sound, touch) and chemical (taste, smell) stimuli. Conductivity- the ability to transmit an impulse resulting from irritation (nerve impulse). The element that perceives irritation and conducts a nerve impulse is a nerve cell (neuron). The nervous system consists of several billion neurons that communicate with each other. The areas of their contacts are called synapses. The contact type of relations in the synapse at various physiological states provides the possibility of a selective reaction to any irritation. In addition, the contact construction of chains of neurons creates the possibility of conducting a nerve impulse in a certain direction. From the cell body, a nerve impulse is carried along a single process - an axon - to other neurons. The sheathed axon is called a nerve fiber. bundles nerve fibers make up the nerves.

Connecting with each other, different tissues form organs. Authority a part of the body that has a certain shape, structure, occupies an appropriate place and performs a specific function is called. Various tissues take part in the formation of any organ, but only one of them is the main one, the rest perform an auxiliary function. For example, connective tissue forms the basis of an organ, epithelial - the mucous membranes of the respiratory and digestive organs, muscular - the walls of hollow organs (esophagus, intestines, bladder, etc.), nervous tissue is presented in the form of nerves innervating the organ, nerve nodes lying in the walls organs. Organs differ in shape, size and position.

Organs whose activities are mutually connected form complexes called systems. Human movements are carried out with the help of the skeletal and muscular systems. Human nutrition is provided by the digestive system, and breathing is provided by the respiratory system. The urinary system and skin serve to remove excess fluids, and the reproductive system is used for reproduction. Blood circulation is carried out by the cardiovascular system, through which nutrients, oxygen and hormones are carried in the body. The connection between tissues and organs, as well as the connection of the body with the external environment, is provided by the nervous system. The skin protects the body and removes waste products in the form of sweat.

The totality of systems forms an integral human body, in which all its constituent parts are interconnected, while the main role in the unification of the body belongs to the cardiovascular, nervous and endocrine systems. These systems work in concert, provide neurohumoral regulation of bodily functions. The nervous system transmits signals in the form of nerve impulses, while the endocrine system releases hormonal substances that are carried by the blood to the organs. The interaction between the cells of the nervous and endocrine systems is carried out with the help of different cellular mediators. Produced in the nervous system in small concentrations, they have only big influence to the endocrine apparatus.

Thus, neurohumoral regulation ensures the coordinated work of all organs, thanks to which the body functions as a whole.

Any harmful effect on one of the systems of the body is reflected in other systems, damaging the entire body as a whole.

The skeletal system is a collection of bones that form when connected to each other with skeleton human body.

Skeleton forms the structural basis of the body, determines its size and shape, performs supporting and protective functions, and together with the muscles forms cavities in which vital organs are located. The skeleton of an adult consists of more than 200 bones, mostly paired.

Skeleton Functions:

1. supporting - attaching muscles and providing support for internal organs;

2. locomotor - the movement of body parts relative to each other and the whole body in space;

3. protective - the bones form a fence of the walls of the cavities containing the internal organs (the lungs are in the chest cavity, the brain is in the cranial cavity, the spinal cord is in the spinal canal);

4. hematopoietic - red bone marrow is a hematopoietic organ;

5. participation in metabolism, mainly mineral (salts of calcium, phosphorus, magnesium, etc.).

Skeleton(Fig. 2) is subdivided into axial(skull, spinal column, chest) and d additional(skeleton limbs).

Scull has two parts: cerebral and facial. The brain part of the skull consists of 2 paired bones (temporal and parietal) and 4 unpaired (frontal, ethmoid, sphenoid and occipital).

The facial section of the skull consists of 6 paired and 3 unpaired bones. The bones of the skull form a receptacle for the brain and form the skeletons of the initial sections of the respiratory system (nasal cavity), digestion (mouth cavity), bone cavities for the organs of vision, hearing and balance. The skull has a number of openings for nerves and blood vessels.

Spine formed by 33-34 vertebrae located one above the other; it surrounds and protects the spinal cord. There are 5 sections of the spine: cervical, consisting of 7 vertebrae, thoracic - from 12, lumbar from 5, sacral - from 5 and coccygeal (caudal) - from 4-5 fused vertebrae.

Rib cage formed by 12 pairs of ribs articulated with the bodies of the thoracic vertebrae and their transverse processes. 7 pairs of upper, true ribs in front are connected to a flat bone - the sternum,

Rice. 2.

Human skeleton (front view):

1 - scull;

2 - spinal column;

3 - collarbone;

4 - edge;

5 - sternum;

6 - brachial bone;

7 - radius;

8 - elbow bone;

9 - wrist bones;

10 - metacarpal bones;

11 - phalanges of fingers;

12 - ilium;

13 - sacrum;

14 - pubic bone;

1 5- ischium;

18- tibia; 16 - femur;

17 - patella;

19 - fibula; 20 - tarsal bones;

21 - metatarsal bones;

22 - phalanges of the toes.

the next three pairs of ribs are connected to each other by cartilage. The two lower pairs of ribs lie freely in the soft tissues.

The thoracic vertebrae, sternum and ribs, together with the respiratory muscles and diaphragm located between them, form the chest cavity.

Upper limb belt consists of two triangular shoulder blades lying on the back of the chest, and clavicles articulated with them, connected to the sternum.

Skeleton of the upper limb formed by the bones: humerus, connected to the scapula, forearm (radius and ulna) and brushes.

hand skeleton formed by small bones of the wrist, long bones of the metacarpus and bones of the fingers.

Belt of the lower extremities consists of two massive flat pelvic bones, firmly fused to the back with the sacrum.

Skeleton of the lower limb consists of bones: femur, lower leg (large and small tibia) and foot.

Foot skeleton formed by the short bones of the tarsus, the long bones of the metatarsus, and the short bones of the legs.

Skeleton bones are a solid support for the soft tissues of the body and levers that move by the force of muscle contraction. The bones of the shoulder, forearm, thigh and lower leg are called tubular. On the surface of the bones there are elevations, depressions, platforms, holes of various sizes and shapes. In the middle part of the tubular bones there is a cavity filled with bone marrow. Bone is a connective tissue, the intercellular substance of which consists of organic material(osseina) and inorganic salts, mainly calcium and magnesium phosphates. It always contains specialized bone cells - osteocytes scattered in the intercellular substance. The bone is permeated with a large number of blood vessels and a number of nerves. FROM outside it is covered by a periosteum (periosteum). The periosteum is a source of osteocyte progenitor cells, and restoration of bone integrity is one of its main functions. Only the articular surfaces are not covered by the periosteum; covers them articular cartilage. Bones are connected to each other by ligaments and joints. In some cases, this connection motionless, for example, the bones of the skull are interconnected due to an uneven, jagged edge; in other cases, the bones are connected by dense fibrous connective tissue. Such a connection sedentary. Movable the connection of bones to each other through cartilage at the end of the bone is called joint. The joint is covered with an articular capsule of dense fibrous connective tissue, which passes into the periosteum. The joint capsules around the joints form a cavity filled with synovial fluid, which acts as a lubricant and ensures minimal friction between the articulating bones. The articular surfaces of the bones are covered with thin, smooth cartilage. The capsule is reinforced with rigid ligaments. Bundles these are dense bundles of fibrous connective tissue located in the thickness of the joint capsule, sometimes in the joint cavity between the articular surfaces, in some joints there are articular discs - menisci, which complement the correspondence of the articular surfaces. The joint is called simple, if it is formed by two bones and difficult if more than two bones are involved. Movements in the joint, depending on its structure, can be: in the horizontal axis - flexion and extension; sagittal axis - adduction and abduction; in the vertical axis - rotation. Rotation is done inside or outside. And in spherical joints, circular motion is possible.

The muscular system is a system of muscles, thanks to which the movements of the bones of the skeleton in the joints are carried out. The total muscle mass is 30-40% of body weight, and for athletes - 45-50%. More than half of all muscles are located in the head and trunk, and 20% - on the upper limbs. There are about 400 muscles in the human body, each muscle consists of many muscle fibers located parallel to each other, dressed in a sheath of loose connective tissue, and has three parts: the body is the abdomen, the initial section is the head and the opposite end is the tail. The head is attached to the bone, which remains motionless during contraction, and the tail is attached to the bone that moves. The contractile part of the muscles, formed by muscle fibers, passes into the tendons at both ends. With their help, skeletal muscles are attached to the bones and set them in motion, other muscles are involved in the formation of the walls of the body cavities - oral, thoracic, abdominal, pelvic. With the help of muscles, the human body is held in a vertical position, moves in space. Breathing is carried out with the help of the pectoral muscles. Tendons are formed by dense fibrous connective tissue that fuses with the periosteum. Tendons are able to withstand a large load when stretched. A damaged tendon, like a ligament, does not recover well, unlike a quickly healing bone. Muscles have a large number of blood vessels necessary for their nutrition, therefore, when muscles are injured, bleeding is profuse.

COVERING SYSTEM. The skin and its derivatives (hair, nails) form the outer surface of the body, which is why it is called the integumentary system. The area of ​​the skin is 1.5–2.0 m 2, depending on the size of the body. The skin consists of two layers: superficial (epidermis) and deep (dermis). The epidermis is made up of many layers of epithelium. The dermis (skin proper) is located under the epidermis and is a connective tissue with some elastic fibers and smooth muscle cells.

Skin integuments in different parts of the body have different thickness and different quantity sebaceous and sweat glands, hair follicles. On the certain areas bodies, skin integuments have hairline of varying intensity: on the head, in the armpit and in the inguinal region, the hairline is more pronounced than in others.

Skin functions:

1. protective - a barrier between the external environment and internal organs, one of the first to react to the influence of the external environment;

2. vitamin-forming - the production of vitamin "D";

3. excretory - sebaceous glands secrete endogenous fat, sweat glands secrete excess fluid.

4. receptor (the skin has a large number of tactile, pain, baroreceptors).

The protective function of the skin is carried out in several ways. outer layer epidermis, consisting of dead cells, resists wear. In case of strong friction, the epidermis thickens and forms calluses. The eyelids protect the cornea of ​​the eye. Eyebrows and eyelashes prevent foreign bodies from entering the cornea. Nails protect the tips of the fingers and toes. Hair also performs a protective function to some extent. The excretion of metabolic products such as salt and water is the function of the sweat glands scattered throughout the body. Specialized nerve endings in the skin sense touch, heat, and cold and relay appropriate stimuli to peripheral nerves.

The nervous system is a unifying and coordinating system of the body: it regulates the activity of individual organs, organ systems and the whole body, it coordinates and integrates the activity of all organs and systems, determining the integrity of the body. Higher nervous activity is associated with the nervous system: consciousness, memory, speech, thinking.

The human nervous system is divided into central and peripheral. The central nervous system (CNS) includes the brain located in the cranial cavity and the spinal cord lying in the spinal canal.

The brain is divided into two cerebral hemispheres and the brainstem. The nervous tissue of the hemispheres forms deep and shallow grooves and convolutions, covered with a thin layer of gray matter - the cortex. Most of the centers of mental activity and higher associative functions are concentrated in the cerebral cortex. The brain stem consists of the medulla oblongata, the pons (the pons), the midbrain, the cerebellum, and the thalamus. The medulla oblongata, in its lower part, is a continuation spinal cord, and its upper part adjoins the bridge. It contains vital important centers regulation of cardiac, respiratory and vasomotor activity. The bridge that connects the two hemispheres of the cerebellum is located between the medulla oblongata and the midbrain; many motor nerves pass through it and several cranial nerves begin or end. Located above the bridge, the midbrain contains the reflex centers of vision and hearing. The cerebellum, which consists of two large hemispheres, coordinates muscle activity. The thalamus, the upper part of the brain stem, transmits all sensory inputs to the cerebral cortex; its lower section - the hypothalamus - regulates the activity of internal organs, exercising control over the activity of the autonomic nervous system. The central nervous system is surrounded by three connective tissue meninges. Between the two of them is the cerebrospinal fluid produced by specialized blood vessels in the brain.

The brain and spinal cord are made up of gray and white matter. Gray matter is a cluster of nerve cells, and white matter is nerve fibers, which are processes of nerve cells. Nerve fibers in the brain and spinal cord form pathways.

The peripheral nervous system includes roots, spinal (31 pairs) and cranial nerves (12 pairs), their branches, nerve plexuses and nodes. Through them, at a speed of up to 100 m/s, nerve impulses propagate to the nerve centers and in reverse order to all organs of the human body.

The nervous system, according to its functional characteristics, is conditionally divided into two large sections - the somatic, or animal, nervous system and the autonomic, or autonomic, nervous system.

somatic nervous system performs mainly the functions of communication of the body with the external environment, providing sensitivity and movement, causing contraction of skeletal muscles. With the help of the somatic system, we feel pain, temperature changes (heat and cold), touch, perceive the weight and size of objects, feel the structure and shape, the position of body parts in space, feel vibration, taste, smell, light and sound. Since the functions of movement and feeling are characteristic of animals and distinguish them from plants, this part of the nervous system is called animal (animal).

autonomic nervous system influences the processes of the so-called plant life, common to animals and plants (metabolism, respiration, excretion, etc.), which is why its name comes from (vegetative - plant). The autonomic nervous system consists of the sympathetic and parasympathetic systems, which receive stimuli from the internal organs, blood vessels, and glands, transmit these stimuli to the central nervous system, and stimulate smooth muscles, cardiac muscle, and glands. Despite a well-defined functional division, both systems are largely connected, but the autonomic nervous system has a certain degree of independence and does not depend on our will, as a result of which it is also called the autonomic nervous system.

According to the definition of I.M. Sechenov, the activity of the nervous system is reflex in nature. Reflex - This is the response of the body to irritation from the external or internal environment, which occurs with the participation of the central nervous system. The reflex is a functional unit of nervous activity. Reflexes are divided into unconditional(congenital, hereditary and fixed) and conditional. FROM unconditioned reflexes(swallowing, sucking, breathing, etc.) the child is born. Their biological function consists in maintaining life, maintaining and regulating the constancy of the internal environment of the organism, as well as ensuring its vital activity. Conditioned reflexes are formed in the course of a person's life under the influence of upbringing, training, and are necessary to adapt the body to the changes taking place around it.

With brain injuries, memory impairment, motor and sensory functions, as well as disorders of mental activity are possible. With damage to the spinal cord and peripheral nerves, there is a violation of sensitivity, complete or partial paralysis of parts of the body, depending on the location of the injury.

sense organs

Sense organs are anatomical formations that perceive external stimuli (sound, light, smell, taste, etc.), transform them into a nerve impulse and transmit it to the brain. The sense organs serve a person for interconnection and adaptation to constantly changing environmental conditions and its knowledge.

Organ of vision. The eye is located in the socket of the skull. The optic nerve emerges from the eyeball, connecting it to the brain. The eyeball consists of the inner core and the surrounding three shells - outer, middle and inner. The outer shell is the sclera, or the albuginea passes in front into the transparent cornea. Below it is the choroid, which passes in front into the ciliary body, where the ciliary muscle is located, which regulates the curvature of the lens, and into the iris, in the center of which there is a pupil. In the inner shell of the eye - the retina - there are light-sensitive receptors - rods and cones. The inner core of the eyeball forms the optical system of the eye and consists of the lens and the vitreous body (Fig. 3).

Organ of hearing. The organ of hearing is divided into the outer, middle and inner ear. The outer ear consists of the auricle and the external auditory meatus. The middle ear is located inside the temporal bone, where the auditory ossicles are located - the hammer, anvil and stirrup, and the auditory tube, which connects the middle ear to the nasopharynx.

Rice. 3. Diagram of the structure of the eye:

1 - sclera; 2 - choroid; 3 - retina;

4 - central fossa; 5 - blind spot; 6 - optic nerve;

7 - conjunctiva; 8- ciliary ligament; 9 -cornea; 10 -pupil;

11 , 18- optical axis; 12 - front camera; 13 - lens;

14 - iris; 15 - rear camera; 16 - ciliary muscle;

17- vitreous body

The inner ear consists of the cochlea, a system of three semicircular canals that form a bony labyrinth in which the membranous labyrinth is located. In a spirally coiled cochlea, auditory receptors - hair cells - are placed. sound waves pass through the external auditory meatus, cause vibrations of the tympanic membrane, which are transmitted through the auditory ossicles to the oval window of the inner ear and cause vibrations of the fluid filling it. These vibrations are converted by auditory receptors into nerve impulses.

vestibular apparatus. The system of three semicircular canals, oval and round sacs form the vestibular apparatus. Receptors of the vestibular apparatus are irritated by the tilt or movement of the head. In this case, reflex muscle contractions occur, which contribute to straightening the body and maintaining an appropriate posture. With the help of receptors of the vestibular apparatus, the position of the head is perceived in the space of movement of the body. Excitations arising in the receptors of the vestibular apparatus enter the nerve centers, carrying out the redistribution of tone and muscle contraction, as a result of which the balance and position of the body in space are maintained.

The organ of taste. On the surface of the tongue, the back of the throat and the soft palate are receptors that perceive sweet, salty, bitter and sour. These receptors are located mainly in the papillae of the tongue, as well as in the mucous membrane of the palate, pharynx and epiglottis. When food is in the oral cavity, a complex of irritations arises and, turning from an irritant into a pathogen, they are transmitted to the cortical part of the taste analyzer of the brain, which is located in the parahippocampal gyrus of the temporal lobe of the cerebral cortex.

Olfactory organ. The sense of smell plays an essential role in human life and is designed to recognize odors, identify gaseous odorous substances contained in the air. In humans, the olfactory organ is located in the upper part of the nasal cavity and has an area of ​​about 2.5 cm2. The olfactory region includes a mucous membrane that covers upper part nasal septum. The receptor layer of the mucous membrane is represented by olfactory cells (epitheliocytes), which perceive the presence of odorous substances, the cortical center of smell is also located in the parahippocampal gyrus. Olfactory sensitivity is a distant type of reception. The distinction of more than 400 different odors is associated with this type of reception.

Internal organs. Internal organs and systems include: respiratory system, cardiovascular system, digestive system, endocrine system, excretory organs.

CARDIOVASCULAR SYSTEM includes the heart and a network of blood vessels (arteries, veins, capillaries).

The heart and blood vessels, considered as a single anatomical and physiological system that provides blood circulation in the body and blood supply to organs and tissues, necessary to deliver oxygen to them, as well as nutrients and remove metabolic products. Due to the function of blood circulation, the cardiovascular system participates in gas exchange and heat exchange between the body and the environment, in the regulation of physiological processes by hormones secreted into the blood and, thereby, in coordinating the various functions of the body.

These functions are directly performed by the fluids circulating in the system - blood and lymph. Lymph is a clear, watery fluid containing white blood cells and found in the lymphatic vessels. From a functional point of view, the cardiovascular system is formed by two related structures: the circulatory system and lymphatic systems oh. The first consists of the heart, arteries, capillaries and veins, which provide a closed blood circulation. The lymphatic system consists of a network of capillaries, nodes and ducts that flow into the venous system.

Blood is a biological tissue that ensures the normal existence of the organism. The amount of blood in men is on average about 5 liters, in women - 4.5 liters; 55% of the blood volume is plasma, 45% - blood cells, the so-called formed elements (erythrocytes, leukocytes, lymphocytes, monocytes, platelets, eosinophils, basophils).

Blood in the human body performs complex and diverse functions. It supplies tissues and organs with oxygen, nutrients, carries away carbon dioxide and metabolic products formed in them, delivers them to the kidneys and skin, through which these toxic substances are removed from the body. The vital, vegetative, function of the blood is to continuously maintain the constancy of the internal environment of the body, deliver the tissues of the hormones, enzymes, vitamins they need, mineral salts and energy substances.

Plasma consists of an aqueous solution of minerals, food, and a small amount of compounds such as hormones, as well as another important component, protein, which makes up the bulk of plasma. Each liter of plasma contains about 75 grams of protein.

Arterial blood, oxygenated bright red. Venous blood, in which there is little oxygen, is dark red in color.

Heart- this is an extremely powerful muscular organ, it pushes blood with such force that it enters all corners of our body, nourishing all our organs with vital oxygen and nutrients. It is located in the lower part of the chest above the diaphragm, between the left and right pleural sacs with the lungs, enclosed in a membrane (pericardium) and fixed on large vessels. The function of the heart is to pump the blood of the body. It consists of two non-communicating halves and four chambers: two atria (left and right) and two ventricles (left and right). The right atrium receives blood (venous) with a low oxygen content from the superior and inferior vena cava. Then the blood passes through the atrioventricular opening with the tricuspid valve and enters the right ventricle, and from it into the pulmonary arteries. The pulmonary veins, carrying arterial, oxygenated blood, flow into the left atrium. Through the atrioventricular opening with a bicuspid valve, blood enters the left ventricle, and from it into the largest artery - the aorta (Fig. 4).

Systemic circulation begins in the left ventricle and ends in the right atrium. The aorta emerges from the left ventricle. It forms an arc, and then goes down along the spine. The part of the aorta located in the chest cavity is called the thoracic aorta, and located in the abdominal cavity is called the abdominal aorta.

Rice. four. Heart:

1 - hollow veins;

2 - right atrium;

3 - right ventricle;

4 - aorta;

5 - pulmonary arteries;

6 - pulmonary veins;

7 - left atrium;

8 - left ventricle.

At the level of the lumbar spine, the abdominal aorta divides into the iliac arteries. In the capillary system, gas exchange occurs in the tissues, and blood returns through the veins of the upper and lower parts of the body, through the larger, superior and inferior vena cava to the right atrium.

Small circle of blood circulation begins in the right ventricle and ends in the left atrium. From the right ventricle, venous blood enters the lungs through the pulmonary arteries. Here, the pulmonary arteries break up into arteries of smaller diameter, passing into the smallest capillaries, which densely braid the walls of the pulmonary alveoli. From the blood in these capillaries, carbon dioxide enters the pulmonary alveoli, and oxygen enters the blood, that is, gas exchange occurs. After saturation with oxygen, the blood flows through the pulmonary veins into the left atrium (Fig. 5).

Blood flow volume, blood pressure and other important hemodynamic parameters are determined not only by the work of the heart as a pump, but also by the function of blood vessels.

Blood vessels. Among the vessels, arteries, veins and capillaries connecting them are distinguished. The walls of blood vessels consist of three layers:

inner shell consists of a connective tissue base;

middle shell, or muscular, is formed by circularly arranged smooth muscle fibers;

outer shell consists of collagen and longitudinal elastic fibers.

The wall of the arteries is thicker than that of the vein due to the better development of the muscle layer. The walls of the aorta and other large arteries, in addition to smooth muscle cells, have a large number of elastic fibers.

Fig.5. Circulation scheme:

1 - capillary network of the upper body;

2 - aorta ;

3 - superior vena cava;

4 - right atrium;

5 - lymphatic duct;

6 - pulmonary artery;

7 - pulmonary veins;

8 - capillary network of the lung;

9 - left ventricle;

10 - celiac trunk;

11 - hepatic vein;

12- capillaries of the stomach;

13 - capillary network of the liver;

14- superior and inferior mesenteric arteries;

15 - portal vein;

16 - inferior vena cava;

17 - intestinal capillaries;

18 - internal iliac artery;

19 - external iliac artery;

20 - capillary network of the lower body.

Elasticity and extensibility allows them to withstand the powerful pressure of pulsating blood. The smooth muscles of the walls of muscular arteries and arterioles regulate the lumen of these vessels and in this way influence the amount of blood reaching any organ. As the arteries move away from the heart, they divide into a tree, the diameter of the vessels gradually decreases and reaches 7-8 microns in the capillaries. The capillary networks in the organs are so dense that if you prick any part of the skin with a needle, then part of the capillaries will surely collapse and blood will come out at the injection site. The walls of the capillaries consist of a single layer of endothelial cells, through their wall oxygen and nutrients are released to the tissues, and carbon dioxide and metabolic products penetrate back into the blood. From the capillaries, blood enters the venules and veins and returns to the heart. Veins that carry blood against gravity have valves to prevent backflow of blood.

Aorta has several divisions: ascending aorta, arch and descending aorta. From the ascending aorta depart the coronary arteries that supply blood to the heart, from the aortic arch - the arteries that supply the head, neck and upper extremities, from the descending aorta - the arteries that deliver blood to the organs of the chest and abdominal cavities, to the pelvic organs and to the lower extremities. Most of the arteries in the human body are found deep in body cavities and channels between muscles. The location and names of the arteries on the limbs correspond to parts of the skeleton (brachial, radial, ulnar, etc.).

Pulse- this is a rhythmic oscillation of the walls of the arteries, synchronous with the contractions of the heart and giving an idea of ​​the frequency, rhythm and strength of heart contractions.

Places for determining the pulse. The heart, contracting rhythmically, pushes blood into the arteries with a powerful stream. This “pressurized” flow of blood provides a pulse that can be felt on an artery passing close to the surface of the skin or over bone.

Pulse detection points:

1. occipital artery;

2. temporal;

3. mandibular;

4. sleepy;

5. subclavian;

6. axillary;

7. shoulder;

8. radial;

10. femoral;

11. tibial.

Circulatory efficiency is assessed using four major arteries: carotid, femoral, radial, and brachial. Knowledge of these arteries is vital for assessing the condition of the circulatory system:

The carotid arteries supply the brain and can be palpated on the right and left sides of the neck, lateral to the trachea.

The femoral arteries supply the lower extremities and can be palpated in the groin area (fold between the abdomen and thigh).

The radial arteries supply the distal part of the upper extremities and can be palpated on the wrist from the side of the palm closer to the thumb.

The brachial arteries supply the upper limbs and can be palpated on the inside of the upper arm between the elbow and the shoulder joint.

Pulse rate is determined by counting pulse fluctuations for 30 seconds, then the result must be multiplied by 2. If the patient's pulse is arrhythmic, then its calculation is carried out within one minute.

The pulse is felt with the thumb of the examiner, in the form of a rhythmic pulsation of the radial artery for 30 seconds. The normal heart rate in adults is 60 to 80 beats per minute, in children it is 78 to 80 at the age of 10 years and older, in five-year-olds it is 98-100, and in newborns it is 120-140 beats.

Pulse Rhythm it is considered correct if the pulse wave passes through certain intervals of time. With arrhythmia, interruptions are always felt.

Pulse voltage is determined by pressing on the artery with a finger until the pulsation stops. Generally, the stronger the pulse, the higher the blood pressure.

Pulse filling - this is the strength of pulse beats, the weaker they are felt, the less filling and the weaker the work of the heart muscle.

A strong, rhythmic pulse means that the heart is efficiently pumping blood throughout the body. A weak pulse means poor circulation. The absence of a pulse indicates cardiac arrest.

RESPIRATORY SYSTEM performs vital important function delivery of oxygen to the tissues of the body and removal of carbon dioxide from the body. Oxygen is a vital element of all living cells of the body, and carbon dioxide is a by-product of cellular metabolism. It includes Airways(nasal cavity, nasopharynx, larynx, trachea, bronchi) and lungs where the process of gas exchange takes place. The nasal cavity and pharynx are united by the concept of "upper respiratory tract". The larynx, trachea and bronchi form the "lower airways". The lungs are divided into lobes: the right - into three, the left - into two (Fig. 6). Shares consist of segments, which are divided into slices, the number of which reaches a thousand. The anatomy of the respiratory system begins with the nasal cavity and mouth, through which air can enter the respiratory system. They connect to the pharynx, which consists of the oropharynx and nasopharynx. Remember that the pharynx has a dual function: a passage for both air and food/water. As a result, airway obstruction is possible here. The tongue is not part of the respiratory system, but it can also block the airways. And they are divided into smaller airways (bronchi, bronchioles). The bronchioles pass into the alveoli, braided with capillaries.

Fig.6. Lungs

1 - larynx; 2 - trachea; 3 - apex of the lung 4 - rib surface; 5 - bifurcation of the trachea; 6 - upper lobe of the lung;

7 - horizontal fissure of the right lung; 8 - oblique slit;

9 - cardiac notch of the left lung; 10 - middle lobe of the lung;

11 - lower lobe of the lung; 12 - diaphragmatic surface;

13 - the base of the lung.

The totality of the alveoli forms the tissue of the lungs, where active gas exchange takes place between blood and air. The respiratory tract consists of tubes, the lumen of which is preserved due to the presence of a bone or cartilaginous skeleton in their walls. This morphological feature is fully consistent with the function of the respiratory tract - conducting air into the lungs and out of the lungs. Because of this, it performs a protective function.

Passing through the respiratory tract, the air is purified, warmed and humidified. During inhalation, air is sucked into them due to an increase in the volume of the chest with a contraction of the external intercostal muscles and the diaphragm. In this case, the pressure inside the lungs becomes less than atmospheric pressure, and air rushes into the lungs. The lungs then exchange oxygen for carbon dioxide.

Reducing the volume of the chest by relaxing the respiratory muscles and the diaphragm provides exhalation. It is very important to monitor the frequency and rhythm of the patient's breathing. The respiratory rate can be determined either by observing the respiratory movements of the chest, or by placing a palm on the epigastric region of the patient. Normally, the respiratory rate in adults ranges from 16 to 20 per minute, and in children a little more often. Breathing can be frequent or rare, deep or shallow. Increased breathing is observed with an increase in temperature and, especially, with diseases of the lungs and heart. In this case, the rhythm of breathing can also be disturbed, when respiratory movements occur at different intervals. Violation of respiratory activity may be accompanied by a change in the color of the skin and mucous membranes of the lips - they acquire a bluish tint (cyanosis). Most often, respiratory distress manifests itself in the form of shortness of breath, in which its frequency, depth and rhythm are disturbed. Severe and rapid shortness of breath is called suffocation, and respiratory arrest asphyxia.

Functions of the respiratory system as a whole:

1. Air supply and regulation of air supply;

2. The airways are the ideal air conditioner for the inhaled air:

mechanical cleaning;

hydration;

warming.

3. External respiration, that is, saturation of the blood with oxygen, removal of carbon dioxide;

4. Endocrine function. The presence of cells that provide local regulation of the functions of the respiratory system, the adaptation of blood flow to ventilation of the lungs;

5. Protective function. Implementation of non-specific (phagocytosis) and specific (immunity) defense mechanisms.

6. Metabolic function. The endothelium of the hemocapillaries of the lungs synthesize numerous enzymes;

7. Filtration function. In the small vessels of the lungs, blood clots and foreign particles linger and dissolve;

8. Depositing function. Depot of blood, lymphocytes, granulocytes;

9. Water exchange, lipid exchange.

In the digestive system, the digestive canal and the digestive glands connected with it by the excretory ducts are distinguished: salivary, gastric, intestinal, pancreas and liver. The alimentary canal in humans has a length of about 8-10 meters and is divided into the following sections: oral cavity, pharynx, esophagus, stomach, small and large intestines, rectum (Fig. 7).

In the oral cavity, food is chewed and crushed by the teeth. In the oral cavity, the initial chemical processing of carbohydrates by saliva enzymes is also carried out, the muscles that push food into the pharynx and esophagus contract, the walls of which contract in waves and move food into the stomach.

Fig.7. Digestive system

The stomach is a sac-like extension of the alimentary canal with a capacity of about 2-3 liters. In its mucous membrane there are about 14 million glands that secrete gastric juice.

The liver is the largest gland of our body, a vital organ whose various functions allow us to call it the "main chemical laboratory of the body."

In the liver, low-molecular toxic substances that enter the blood are neutralized, bile is continuously produced, which accumulates in the gallbladder, and enters the duodenum when the digestion process takes place in it. The pancreas secretes digestive juice into the duodenum, which contains enzymes that break down food nutrients. Digestion of food is carried out under the influence of digestive enzymes, which are contained in the secretions of the salivary glands, the ducts of which open into the oral cavity, and are also part of the gastric juice, pancreatic juice and intestinal juice produced by the small glands of the mucous membrane of the small intestine. The presence of folds and villi increases the total absorptive surface of the small intestine, because. it is here that the processes of absorption of the main nutrients contained in the digested food take place. The total suction surface of the small intestine reaches 500 square meters. Undigested food remains are excreted through the anus.

The function of the digestive system is the mechanical and chemical processing of food entering the body, the absorption of processed, and the release of unabsorbed and unprocessed substances.

Organs of excretion. Decay products are excreted from the body in the form of aqueous solutions - through the kidneys (90%), through the skin with sweat (2%); gaseous - through the lungs (8%).

The end products of the body's protein metabolism in the form of urea, uric acid, creatinine, products of incomplete oxidation of organic substances (acetone bodies, lactic and acetoacetic acids), salts, endogenous and exogenous toxic substances dissolved in water are mainly removed from the body through the kidney. The urinary system is involved in filtering and excreting waste products and toxins from the body. In the cells of the human body, the process of metabolism (assimilation and dissimilation) is constantly taking place. The end products of metabolism must be removed from the body. They enter the blood from the cells, and are removed from the blood mainly due to the urinary system. This system includes the right and left kidneys, ureters, bladder and urethra. All blood constantly flows through the kidneys and is cleared of metabolic products harmful to the body. The daily amount of urine in an adult is normally 1.2 - 1.8 liters and depends on the fluid that has entered the body, ambient temperature and other factors. The bladder is a container with a capacity of about 500 ml for the accumulation of urine. Its shape and size depend on the degree of filling with urine.

The normal function of the excretory system maintains the acid-base balance and ensures the activity of the organs and systems of the body. Delay and accumulation of end products of metabolism in the body can cause profound changes in many internal organs.

The endocrine system consists of endocrine glands that do not have excretory ducts. They produce chemicals called hormones that have a powerful effect on the functions of various human organs: some hormones accelerate the growth and formation of organs and systems, others regulate metabolism, determine behavioral responses etc. The endocrine glands include: pituitary gland, pineal gland, thyroid, parathyroid and thymus glands, pancreas and adrenal glands, ovaries and testes. Anatomically separate endocrine glands influence each other. Due to the fact that this effect is provided by hormones delivered by the blood to target organs, it is customary to talk about humoral regulation these organs. However, it is known that all processes occurring in the body are under constant control of the central nervous system. This dual regulation of organ activity is called neurohumoral. Changes in the functions of the endocrine glands cause severe disorders and diseases of the body, including mental disorders.

So, we have considered the anatomical and physiological characteristics of the body systems, since a prerequisite for the assimilation of the principles of first aid is knowledge of the activities of the human body. This is a paramount condition for its successful and consistent implementation and correct rendering in specific conditions.

Man is the most advanced living being that lives on Earth. This opens the possibility of self-knowledge and study of the structure of one's own body. Anatomy studies the structure of the human body. Physiology studies the functioning of organs and the entire human body.

The human body is a kind of hierarchical sequence, from simple to complex:

Cell;
- Textile;
- Organ;
- System.

Cells similar in structure are combined into tissues that have their own clear purpose. Each type of tissue is folded into certain organs, which also carry individual functions. Organs, in turn, are formed into systems that regulate human life.

Each of the 50 trillion microcells in the body perform certain function. In order to better understand human anatomy and physiology, it is necessary to consider all body systems.

12 systems blink to fully exist for a person:

Skeletal or supporting (bones, cartilage, ligaments);
- Muscular or motor (muscles);
- Nervous (brain, spinal cord nerves);
- Endocrine (regulation of hormonal levels);
- Circulation (responsible for the nutrition of cells);
- Lymphatic (responsible for fighting infections);
- Digestive (digests food, filtering useful substances);
- Respiratory (human lungs);
- Integumentary, protective (skin, hair, nails);
- Reproductive (male and female organs breeding);
- Excretory (liberates the body from unnecessary or harmful substances);
- Immune (responsible for the state of immunity in general).

Skeletal or musculoskeletal (bones, cartilage, ligaments) system

The basis of our movement is the skeleton, which is the main support for everything else. Muscles are attached to the skeleton, they are attached with the help of ligaments (muscles can stretch, there are no ligaments), thanks to which the bone can be raised or pushed back.

Analyzing the properties of the skeletal system, it can be noted that the main thing in it is the support for the body and the protection of internal organs. The human supporting skeleton includes 206 bones. The main axis consists of 80 bones, the additional skeleton consists of 126.

Human bone types

There are four types of bones:

Tubular bones. Tubular bones line up the limbs, they are long and suitable for this.

Mixed bones. Mixed dice can contain all of the above types of dice in two or three variants. An example is the vertebral bone, clavicle, etc.

Flat bones. Flat bones are suitable for attaching large muscle groups. In them, the width prevails over the thickness. Short are bones in which the length is equal to the width of the bone.

Short bones. Short are bones in which the length is equal to the width of the bone.

Bones of the human skeletal system

Main bones of the human skeletal system:

Scull;
- Lower jaw;
- Clavicle;
- Spatula;
- Sternum;
- Rib;
- Shoulder;
- spinal column;
- Elbow;
- Beam;
- Metacarpus bones;
- Phalanges of fingers;
- Taz;
- sacrum;
- Femoral;
- Knee cap;
- Big tibia;
- Small tibia;
- Tarsal bones;
- Metatarsal bones;
- Phalanges of the toes.

The structure of the human skeleton

The structure of the skeleton is distinguished:

Body skeleton. The skeleton of the body consists of the spine and chest.
- The skeleton of the limbs (upper and lower). The skeleton of the limbs is usually divided into the skeleton of free limbs (arms and legs) and the skeleton of the girdle (shoulder girdle and pelvic girdle).

The hand skeleton is made up of:

Shoulder, consisting of one bone, the humerus;
- forearms, which form two bones (radius and ulna) and brushes.

The leg skeleton is divided into three sections:

The thigh, which consists of one bone, the femur;
- lower leg formed by the fibula and tibia);
- foot, which has in its composition the tarsus, metatarsus and phalanges of the fingers.

The shoulder girdle is formed by two paired bones:

shoulder blade;
- clavicle.

The pelvic skeleton is made up of:

Paired pelvic bones.

Skeleton brushes form:

Wrists;
- metacarpus;
- phalanges of fingers.

The structure of the human spine

Man became upright due to the special structure of his spine. It runs along the entire body and rests on the pelvis, where it gradually ends. The last bone is the coccyx, it is assumed that earlier it was the tail. There are 24 vertebrae in the human spinal column. Through it passes the back of the brain, which is connected to the brain.

The spine is divided into sections, there are five in total:

The cervical region consists of 7 vertebrae;
- the thoracic region consists of 12 vertebrae;
- the lumbar region consists of 5 vertebrae;
- the sacral department consists of 5 vertebrae;
- coccygeal consists of 4-5 rudimentary vertebrae fused together.

Muscular system

The main function of the muscular system is to contract under the influence of electrical impulses, thereby providing the function of movement.
Innervation is carried out at the cellular level. Muscle cells are the structural unit of a muscle fiber. Muscles are formed from muscle fibers. Muscle cells have a special function - contraction. The contraction occurs under the influence of a nerve impulse, due to which a person can perform actions such as walking, running, squatting, even blinking is performed by muscle cells.

The muscular system is made up of three types:

Skeletal (striated);
- Smooth;
- Muscles of the heart.

striated muscles

Striated muscle tissue has a high rate of contraction, so it performs all motor functions.

The striated muscles are:

Smooth muscles

Smooth muscle tissue contracts autonomously under the influence of adrenaline and acetylcholine, and the rate of contraction is noticeably lower. Smooth muscles line the walls of organs and blood vessels and are responsible for internal processes, for example, digestion of food, movement of blood (due to constriction and expansion of blood vessels).

Muscles of the heart

Cardiac muscle - this is composed of striated muscle tissue but works autonomously.

Nervous system

Nervous tissue is used to receive and transmit electrical impulses.

Nervous tissue has three types:

The first type receives signals from the external environment and sends them to the central nervous system. The largest number of receptors is in the mouth.

The second type of contact neurons, their main task is to receive, process and transmit information, it can also store the impulses that passed through it.

The third type of motor is also called efferent, they deliver impulses to the working organs.

The nervous system is controlled by the brain and consists of billions of neurons. The brain, combined with the spinal cord, form the central nervous system, and the nerves are the peripheral system.

It is fashionable to highlight several main nerve endings:

Brain;
- cranial nerve;
- Nerve going to the hand;
- spinal nerve;
- Spinal cord;
- Nerve leading to the leg.

Endocrine system

The endocrine system is a set of biologically active elements that regulate growth, weight, reproduction and many other vital functions. important processes organism.
Hormones are chemical messengers released by the endocrine system into the blood. glands endocrine system located in the craniocerebral box, sternum and in the abdominal cavity.

Identify the main parts of the endocrine system:

Pituitary;
- Epiphysis;
- Thyroid;
- Thymus (thymus gland);
- Adrenal;
- Pancreas;
- Ovaries (produce the female sex hormone);
- Testicles (produce the male sex hormone).

Circulatory system

The circulatory system is one of the main human systems.

The circulatory system is represented:

Heart;
- Blood vessels;
- Blood.

The heart is a so-called pump that pumps blood in one direction through the circulatory network. The length of blood vessels in the human body is about 150 thousand kilometers, each of which performs an individual function.

Large vessels of the circulatory system:

Jugular vein;
- Subclavian vein;
- Aorta;
- Pulmonary artery;
- Femoral vein;
- Carotid artery;
- Superior vena cava;
- Subclavian artery;
- Pulmonary vein;
- Inferior vena cava;
- Femoral artery.

lymphatic system

The lymphatic system filters intercellular fluids and destroys pathogenic microbes. The main functions of the lymphatic system are tissue drainage and a protective barrier. The lymphatic system permeates 90% of body tissues.

High-quality work of the lymphatic system occurs due to the following organs:

Thoracic tributary, which flows into the left subclavian vein;
- Right lymphatic tributary, which flows into the right subclavian vein;
- Thymus;
- Thoracic duct;
- The spleen is a kind of blood depot;
- The lymph nodes;
- Lymphatic vessels.

Digestive system

The main and main function of the digestive system is the process of digesting food.

The process of digestion of food includes 4 stages:

ingestion;
- Digestion;
- Suction;
- Removal of waste.

Each stage of digestion is assisted by certain organs that make up the digestive system.

Respiratory system

For proper life, a person needs oxygen, which enters the body due to the work of the lungs - the main organs of the respiratory system.
First, the air enters the nose, then, after which, passing through the pharynx and larynx, it enters the trachea, which, in turn, is divided into two bronchi and enters the lungs. Thanks to gas exchange, cells constantly receive oxygen and are freed from carbon dioxide, which is harmful to their existence.

integumentary system

The integumentary system is the living shell of the human body. Skin, hair and nails are a "wall" between the internal organs of a person and the external environment.

The skin is a waterproof shell capable of maintaining body temperature within 37 degrees. The skin protects the internal organs from infection and harmful sunlight.

Hair protects the skin from mechanical damage, cooling and overheating. The hairline is absent only on the lips, palms and soles of the feet.

The nail plates carry the protective function of the sensitive tips of the fingers and toes.

reproductive system

The reproductive system saves the human species from extinction. Male and female reproductive organs are different in their functions and structure.

The male reproductive system consists of the following organs:

vas deferens;
- Urethra;
- Testicle;
- epididymis;
- Penis.

The structure of the female reproductive system is fundamentally different from the male:

Uterus;
- Fallopian tube;
- Ovary;
- Cervix;
- Vagina.

excretory system

Excretory system - removes the original metabolic products from the body, preventing its poisoning. The excretion of harmful substances occurs with the help of the lungs, skin, liver and kidneys. The main one is the urinary system.

The urinary system consists of the following organs:

2 kidneys;
- 2 ureters;
- Bladder;
- Urethra.

The immune system

The human body is constantly threatened by pathogenic viruses and bacteria, the immune system is a fairly reliable defense against such exposure.
The immune system is a collection of leukocytes, white blood cells, they recognize antigens and help in the fight against pathogenic microorganisms.

Finally

Over the centuries, the understanding of the structure and functioning of the human body has changed dramatically. Thanks to observations and the emergence of anatomical science, a global study of human physiology became possible.

Anatomy and Physiology

Textbook

INTRODUCTION

Human anatomy and physiology is one of the biological disciplines that form the basis of the theoretical and practical training of teachers, athletes, doctors and nurses.
Anatomy - it is a science that studies the form and structure of an organism in connection with its functions, development and under the influence of the environment.
Physiology - the science of the regularities of the life processes of a living organism, its organs, tissues and cells, their relationship when changing various conditions and state of the body.
Human anatomy and physiology are closely related to all medical specialties. Their achievements constantly influence the practice of medicine. It is impossible to carry out qualified treatment without knowing well the anatomy and physiology of a person. Therefore, before studying clinical disciplines, they study anatomy and physiology. These subjects form the foundation of medical education and medical science in general.
The structure of the human body by systems studies systematic (normal) anatomy.
The structure of the human body by region, taking into account the position of the organs and their relationship with each other, studies with the skeleton topographic anatomy.
Plastic anatomy considers the external forms and proportions of the human body, as well as the topography of organs in connection with the need to explain the features of the physique; age anatomy - the structure of the human body depending on age.
pathological anatomy studies organs and tissues damaged by a particular disease.
The totality of physiological knowledge is divided into a number of separate but interrelated areas - general, special (or private) and applied physiology.
General physiology includes information that relates to the nature of the main life processes, general manifestations of vital activity, such as the metabolism of organs and tissues, general patterns of the body's response (irritation, excitation, inhibition) and its structures to environmental influences.
Special (private) physiology explores the characteristics of individual tissues (muscle, nervous, etc.), organs (liver, kidneys, heart, etc.), the patterns of combining them into systems (respiratory, digestive, circulatory systems).
Applied Physiology studies the patterns of manifestations of human activity in connection with special tasks and conditions (physiology of labor, nutrition, sports).
Physiology is conventionally divided into normal and pathological. The first studies the patterns of life healthy body, mechanisms of adaptation of functions to the influence of various factors and the stability of the organism. Pathological physiology considers changes in the functions of a diseased organism, finds out the general patterns of the appearance and development of pathological processes in the body, as well as the mechanisms of recovery and rehabilitation.

Short story development of anatomy and physiology

The development and formation of ideas about anatomy and physiology begin with ancient times.
Among the first known history of anatomists should be called Alkemon from Kratona, who lived in the 5th century. BC e. He was the first to dissect (dissect) the corpses of animals in order to study the structure of their bodies, and suggested that the sense organs are connected directly with the brain, and the perception of feelings depends on the brain.
Hippocrates(c. 460 - c. 370 BC) - one of the prominent medical scientists of ancient Greece. He attached paramount importance to the study of anatomy, embryology and physiology, considering them the basis of all medicine. He collected and systematized observations on the structure of the human body, described the bones of the skull roof and the joints of the bones with sutures, the structure of the vertebrae, ribs, internal organs, the organ of vision, muscles, large vessels.
The outstanding natural scientists of their time were Plato (427-347 BC) and Aristotle (384-322 BC). Studying anatomy and embryology, Plato revealed that the brain of vertebrates develops in the anterior sections of the spinal cord. Aristotle, opening the corpses of animals, he described their internal organs, tendons, nerves, bones and cartilage. According to him, the main organ in the body is the heart. He named the largest blood vessel the aorta.
A great influence on the development of medical science and anatomy had Alexandria Medical School, which was created in the III century. BC e. Doctors of this school were allowed to dissect human corpses for scientific purposes. During this period, the names of two outstanding anatomists became known: Herophilus (born c. 300 BC) and Erasistratus (c. 300 - c. 240 BC). Herophilus described the membranes of the brain and the venous sinuses, the ventricles of the brain and the choroid plexuses, the optic nerve and the eyeball, the duodenum and mesenteric vessels, and the prostate. Erasistratus He described the liver, bile ducts, heart and its valves quite fully for his time; knew that blood from the lung enters the left atrium, then into the left ventricle of the heart, and from there through the arteries to the organs. The Alexandrian school of medicine also belongs to the discovery of a method of ligation of blood vessels in case of bleeding.
The most prominent scientist in various fields of medicine after Hippocrates was the Roman anatomist and physiologist Claudius Galen(c. 130 - c. 201). He first began to teach a course in human anatomy, accompanied by an autopsy of the corpses of animals, mainly monkeys. The autopsy of human corpses was prohibited at that time, as a result of which Galen, facts without proper reservations, transferred the structure of the animal body to humans. Possessing encyclopedic knowledge, he described 7 pairs (out of 12) of cranial nerves, connective tissue, muscle nerves, blood vessels of the liver, kidneys and other internal organs, periosteum, ligaments.
Important information was obtained by Galen about the structure of the brain. Galen considered it the center of sensitivity of the body and the cause of voluntary movements. In the book "On Parts of the Human Body" he expressed his anatomical views and considered the anatomical structure in close connection with the function.
The authority of Galen was very great. Medicine has been taught from his books for nearly 13 centuries.
A Tajik doctor and philosopher made a great contribution to the development of medical science Abu Ali Ibn Son, or Avicenna(c. 980-1037). He wrote the "Canon of Medicine", which systematized and supplemented information on anatomy and physiology, borrowed from the books of Aristotle and Galen. Avicenna's books were translated into Latin and reprinted more than 30 times.
Starting from the XVI-XVIII centuries. Universities are being opened in many countries, medical faculties are being established, and the foundations of scientific anatomy and physiology are being laid. An especially great contribution to the development of anatomy was made by the Italian scientist and artist of the Renaissance. Leonardo da Vinci(1452-1519). He dissected 30 corpses, made many drawings of bones, muscles, internal organs, providing them with written explanations. Leonardo da Vinci laid the foundation for plastic anatomy.
The founder of scientific anatomy is considered a professor at the University of Padua Andras Vesalius(1514-1564), who, on the basis of his own observations made during the autopsy, wrote a classic work in 7 books "On the structure of the human body" (Basel, 1543). In them, he systematized the skeleton, ligaments, muscles, blood vessels, nerves, internal organs, brain and sensory organs. Research Vesalius and the publication of his books contributed to the development of anatomy. In the future, his students and followers in the XVI-XVII centuries. made many discoveries, described in detail many human organs. The names of some organs of the human body are associated with the names of these scientists in anatomy: G. Fallopius (1523-1562) - fallopian tubes; B. Eustachius (1510-1574) - Eustachian tube; M. Malpighi (1628-1694) - Malpighian bodies in the spleen and kidneys.
Discoveries in anatomy served as the basis for deeper research in the field of physiology. The Spanish physician Miguel Servet (1511-1553), a student of Vesalius R. Colombo (1516-1559) suggested the passage of blood from the right half of the heart to the left through the pulmonary vessels. After numerous studies, the English scientist William Harvey(1578-1657) published the book Anatomical Study of the Movement of the Heart and Blood in Animals (1628), where he provided proof of the movement of blood through the vessels of the systemic circulation, and also noted the presence of small vessels (capillaries) between arteries and veins. These vessels were discovered later, in 1661, by M. Malpighi, the founder of microscopic anatomy.
In addition, W. Harvey introduced vivisection into the practice of scientific research, which made it possible to observe the work of animal organs using tissue cuts. The discovery of the doctrine of blood circulation is considered to be the date of foundation of animal physiology.
Simultaneously with the discovery of W. Harvey, a work was published Casparo Azelli(1591-1626), in which he made an anatomical description of the lymphatic vessels of the mesentery of the small intestine.
During the XVII-XVIII centuries. not only new discoveries in the field of anatomy appear, but a number of new disciplines begin to emerge: histology, embryology, and somewhat later - comparative and topographic anatomy, anthropology.
For the development of evolutionary morphology, the doctrine played an important role Ch. Darwin(1809-1882) on influence external factors on the development of forms and structures of organisms, as well as on the heredity of their offspring.
Cell theory T. Schwanna (1810-1882), evolutionary theory Ch. Darwin set a number of new tasks for anatomical science: not only to describe, but also to explain the structure of the human body, its features, to reveal the phylogenetic past in anatomical structures, to explain how its individual features developed in the process of historical development of man.
To the most significant achievements of the XVII-XVIII centuries. applies formulated by the French philosopher and physiologist Rene Descartes notion of "reflected activity of the organism". He introduced the concept of reflex into physiology. The discovery of Descartes served as the basis for the further development of physiology on a materialistic basis. Later ideas about nervous reflex, reflex arc, the importance of the nervous system in the relationship between the external environment and the body were developed in the works of the famous Czech anatomist and physiologist G. Prohasky(1748-1820). Achievements in physics and chemistry made it possible to apply more precise research methods in anatomy and physiology.
In the XVIII-XIX centuries. especially significant contribution in the field of anatomy and physiology was made by a number of Russian scientists. M. V. Lomonosov(1711-1765) discovered the law of conservation of matter and energy, suggested the formation of heat in the body itself, formulated a three-component theory of color vision, gave the first classification taste sensations. Student of M. V. Lomonosov A. P. Protasov(1724-1796) - the author of many works on the study of human physique, structure and functions of the stomach.
Professor of Moscow University S. G. Zabelin(1735-1802) lectured on anatomy and published the book "A word about the additions of the human body and ways to protect them from diseases", where he expressed the idea of ​​​​the common origin of animals and humans.
In 1783 Ya. M. Ambodik-Maksimovich(1744-1812) published the Anatomical and Physiological Dictionary in Russian, Latin and French and in 1788 A. M. Shumlyansky(1748-1795) in his book described the capsule of the renal glomerulus and the urinary tubules.
An important place in the development of anatomy belongs to E. O. Mukhina(1766-1850), who taught anatomy for many years, wrote tutorial"Course of Anatomy".
The founder of topographic anatomy is N. I. Pirogov(1810-1881). He developed an original method for studying the human body on cuts of frozen corpses. He is the author of such well-known books as "A Complete Course in Applied Anatomy of the Human Body" and "Topographic Anatomy Illustrated by Cuts Through the Frozen Human Body in Three Directions". N. I. Pirogov studied and described the fasciae, their relationship with blood vessels with particular care, attaching great practical importance to them. He summarized his research in the book Surgical Anatomy of Arterial Trunks and Fascia.
Functional anatomy was founded by an anatomist P. F. Les-gaft(1837-1909). His provisions on the possibility of changing the structure of the human body through the impact of physical exercises on the functions of the body are the basis of the theory and practice of physical education. .
P. F. Lesgaft was one of the first to use the method of radiography for anatomical studies, the experimental method on animals and the methods of mathematical analysis.
The works of famous Russian scientists K. F. Wolf, K. M. Baer and X. I. Pander were devoted to the issues of embryology.
In the XX century. successfully developed functional and experimental directions in anatomy such research scientists as V.N. Tonkov (1872-1954), B.A. Dolgo-Saburov (1890-1960), V.N. Shevkunenko (1872-1952), V.P. -1937), D.A. Zhdanov (1908-1971) and others.
Formation of physiology as an independent science in the XX century. significantly contributed to the successes in the field of physics and chemistry, which gave researchers accurate methodological techniques that made it possible to characterize the physical and chemical essence physiological processes.
I. M. Sechenov(1829-1905) entered the history of science as the first experimental researcher of a complex phenomenon in the field of nature - consciousness. In addition, he was the first who managed to study the gases dissolved in the blood, to establish the relative effectiveness of the influence of various ions on physicochemical processes in a living organism, and to clarify the phenomenon of summation in the central nervous system (CNS). I. M. Sechenov received the greatest fame after the discovery of the process of inhibition in the central nervous system. After the publication in 1863 of the work of I. M. Sechenov "Reflexes of the brain", the concept of mental activity was introduced into the physiological foundations. Thus, a new view was formed on the unity of the physical and mental foundations of man.
The development of physiology was greatly influenced by the work I. P. Pavlova(1849-1936). He created the doctrine of the higher nervous activity of man and animals. Investigating the regulation and self-regulation of blood circulation, he established the presence of special nerves, of which some increase, others delay, and others change the strength of heart contractions without changing their frequency. At the same time, IP Pavlov also studied the physiology of digestion. Having developed and put into practice a number of special surgical techniques, he created a new physiology of digestion. Studying the dynamics of digestion, he showed its ability to adapt to excitatory secretion when eating various foods. His book "Lectures on the work of the main digestive glands" became a guide for physiologists around the world. For work in the field of physiology of digestion in 1904, IP Pavlov was awarded the Nobel Prize. His discovery of the conditioned reflex made it possible to continue the study of the mental processes that underlie the behavior of animals and humans. The results of many years of research by IP Pavlov were the basis for the creation of the doctrine of higher nervous activity, in accordance with which it is carried out by the higher parts of the nervous system and regulates the relationship of the organism with the environment.
Belarusian scientists also made a significant contribution to the development of anatomy and physiology. Opening in 1775 in Grodno of the Medical Academy, headed by a professor of anatomy J. E. Gilibert(1741-1814), contributed to the teaching of anatomy and other medical disciplines in Belarus. At the academy, an anatomical theater and a museum were created, as well as a library, which contained many books on medicine.
A native of Grodno made a significant contribution to the development of physiology August Becu(1769-1824) - the first professor of the independent department of physiology at Vilna University.
M. Gomolitsky(1791-1861), who was born in the Slonim district, from 1819 to 1827 headed the Department of Physiology at Vilna University. He conducted extensive experiments on animals, dealt with the problems of blood transfusion. His doctoral dissertation was devoted to the experimental study of physiology.
FROM. B. Yundzill, a native of the Lida district, professor of the department natural sciences Vilna University, continued the research begun by Zh. E. Zhiliber, published a textbook on physiology. S. B. Yundzill believed that the life of organisms is located in in constant motion and connections with the external environment, "without which the existence of the organisms themselves is impossible." Thus, he approached the position of the evolutionary development of living nature.
I. O. Cybulsky(1854-1919) first singled out in 1893-1896. active extract of the adrenal glands, which later made it possible to obtain the hormones of this endocrine gland in its pure form.
The development of anatomical science in Belarus is closely connected with the discovery in 1921 of Faculty of Medicine in Belarusian state university. The founder of the Belarusian school of anatomists is Professor S. I. Lebed-kin, who headed the department of anatomy of Minsk medical institute from 1922 to 1934. The main direction of his research was the study of the theoretical foundations of anatomy, the definition of the relationship between form and function, as well as the elucidation of the phylogenetic development of human organs. He summarized his research in the monograph "Biogenetic Law and Theory of Recapitulation", published in Minsk in 1936. The research of the famous scientist is devoted to the development of the peripheral nervous system and reinnervation of internal organs. D. M. Golub, Academician of the Academy of Sciences of the BSSR, who headed the Department of Anatomy of the Moscow State Medical Institute from 1934 to 1975. In 1973, D. M. Golub was awarded the State Prize of the USSR for a series of fundamental works on the development of the autonomic nervous system and reinnervation of internal organs.
For the last two decades, the ideas of S. I. Lebedkin and D. M. Golub have been fruitfully developed by Professor P. I. Lobko. The main scientific problem of the team he heads is the study of theoretical aspects and patterns of development of vegetative nodes, trunks and plexuses in human and animal embryogenesis. Row installed general patterns formation of the nodal component of the autonomic nerve plexuses, extra- and intraorganic nerve nodes, etc. For the textbook "Autonomic nervous system" (atlas) (1988) P. I. Lob-ko, S. D. Denisova and P. G. Pivchenko in 1994 State Prize of the Republic of Belarus was awarded.
Targeted research in human physiology is associated with the creation in 1921 of the corresponding department at the Belarusian State University and in 1930 at the Moscow State Medical Institute. Here, questions of blood circulation, nervous mechanisms of regulation of the functions of the cardiovascular system (I. A. Vetokhin), questions of the physiology and pathology of the heart (G. M. Pruss and others), compensatory mechanisms in the activity of the cardiovascular system (A. Yu. Bronovitsky, A. A. Krivchik), cybernetic methods of regulation of blood circulation in health and disease (G. I. Sidorenko ), functions of the insular apparatus (G. G. Gacko).
Systematic physiological research began in 1953 at the Institute of Physiology of the ANSSR , where the original direction was taken to study the autonomic nervous system.
A significant contribution to the development of physiology in Belarus was made by Academician I. A. Bulygin. He devoted his research to the study of the spinal cord and brain, the autonomic nervous system. In 1972, I. A. Bulygin was awarded the State Prize of the BSSR for the monographs “Investigations into the Patterns and Mechanisms of Interoreceptive Reflexes” (1959), “Afferent Pathways of Interoreceptive Reflexes” (1966), “Chain and Tubular Neurohumoral Mechanisms of Visceral Reflex Reactions” (1970) , and for a series of works published in 1964-1976. "New principles of the organization of autonomic ganglia", in 1978 State Prize of the USSR.
Scientific research of the academician N. I. Arinchina associated with the physiology and pathology of blood circulation, comparative and evolutionary gerontology. He developed new methods and apparatus for a comprehensive study of the cardiovascular system.
Physiology of the XX century. characterized by significant achievements in the field of disclosure of the activities of organs, systems, the body as a whole. A feature of modern physiology is a deep analytical approach to the study of membrane, cellular processes, the description of the biophysical aspects of excitation and inhibition. Knowledge of the quantitative relationships between various processes makes it possible to carry out their mathematical modeling, to find out certain violations in a living organism.

Research methods

To study the structure of the human body and its functions, various research methods are used. For studying morphological features there are two groups of methods. The first group is used to study the structure of the human body on cadaveric material, and the second - on a living person.
AT first group includes:
1) dissection method using simple tools(scalpel, tweezers, saw, etc.) - allows you to study. structure and topography of organs;
2) the method of soaking corpses in water or in a special liquid for a long time to isolate the skeleton, individual bones to study their structure;
3) the method of sawing frozen corpses - developed by N. I. Pirogov, allows you to study the relationship of organs in a single part of the body;
4) corrosion method - used to study blood vessels and other tubular formations in internal organs by filling their cavities with hardening substances (liquid metal, plastics), and then destroying the tissues of organs with the help of strong acids and alkalis, after which a cast of poured formations remains;
5) injection method - consists in introducing dyes into organs with cavities, followed by clarification of the parenchyma of organs with glycerin, methyl alcohol, etc. It is widely used to study the circulatory and lymphatic systems, bronchi, lungs, etc .;
6) microscopic method - used to study the structure of organs with the help of devices that give an enlarged image.

Co. second group relate:
1) X-ray method and its modifications (fluoroscopy, radiography, angiography, lymphography, X-ray kymography, etc.) - allows you to study the structure of organs, their topography on a living person at different periods of his life;
2) somatoscopic (visual examination) method of studying the human body and its parts - used to determine the shape of the chest, the degree of development of individual muscle groups, curvature of the spine, body constitution, etc .;
3) anthropometric method - studies the human body and its parts by measuring, determining the proportion of the body, the ratio of muscle, bone and adipose tissue, the degree of joint mobility, etc .;
4) endoscopic method - makes it possible to examine on a living person using light guide technology inner surface digestive and respiratory systems, cavities of the heart and blood vessels, urogenital apparatus.
In modern anatomy, new research methods are used, such as computed tomography, ultrasound echolocation, stereophotogrammetry, nuclear magnetic resonance, etc.
In turn, histology stood out from anatomy - the study of tissues and cytology - the science of the structure and function of the cell.
For the study of physiological processes are usually used experimental methods.
In the early stages of the development of physiology, extirpation method(removal) of an organ or part thereof, followed by observation and registration of the obtained indicators.
fistula method is based on the introduction of a metal or plastic tube into a hollow organ (stomach, gallbladder, intestines) and fixing it to the skin. Using this method, the secretory function of organs is determined.
Catheterization method used to study and record the processes that occur in the ducts of the exocrine glands, in the blood vessels, the heart. With the help of thin synthetic tubes - catheters - various drugs are administered.
Denervation method is based on cutting the nerve fibers innervating the organ in order to establish the dependence of the function of the organ on the influence of the nervous system. To excite the activity of an organ, an electrical or chemical type of irritation is used.
In recent decades, they have been widely used in physiological research. instrumental methods(electrocardiography, electroencephalography, registration of the activity of the nervous system by implantation of macro- and microelements, etc.).
Depending on the form of the physiological experiment, it is divided into acute, chronic, and under conditions of an isolated organ.
acute experiment designed for artificial isolation of organs and tissues, stimulation of various nerves, registration electrical potentials, drug administration, etc.
chronic experiment is used in the form of targeted surgical operations (imposition of fistulas, neurovascular anastomoses, transplantation various organs, implantation of electrodes, etc.).
The function of an organ can be studied not only in the whole organism, but also isolated from it. In this case, the organ is provided with all the necessary conditions for its vital activity, including the supply of nutrient solutions to the vessels of the isolated organ. (perfusion method).
The use of computer technology in conducting a physiological experiment has significantly changed its technique, methods of registering processes and processing the results obtained.

Cells and tissues

The human body is a component of elements that work together in order to effectively perform all vital functions.

Cells

Cell - it is a structural and functional unit of a living organism, capable of division and exchange with the environment. It carries out the transfer of genetic information by self-reproduction.
Cells are very diverse in structure, function, shape, and size (Fig. 1). The latter range from 5 to 200 microns. The largest in the human body are the egg and nerve cell, and the smallest are blood lymphocytes. The shape of the cells are spherical, spindle-shaped, flat, cubic, prismatic, etc. Some cells, together with processes, reach a length of up to 1.5 m or more (for example, neurons).

Rice. 1. Cell shapes:
1 - nervous; 2 - epithelial; 3 - connective tissue; 4 - smooth muscle; 5- erythrocyte; 6- sperm; 7-ovum

Each cell has complex structure and is a system of biopolymers, contains a nucleus, cytoplasm and organelles located in it (Fig. 2). The cell is separated from the external environment by the cell wall. plasmalemma(thickness 9-10 mm), which transports the necessary substances into the cell, and vice versa, interacts with neighboring cells and intercellular substance. Inside the cell is nucleus, in which protein synthesis occurs, it stores genetic information in the form of DNA (deoxyribonucleic acid). The nucleus may be round or ovoid in shape, but in flat cells it is somewhat flattened, and in leukocytes it is rod-shaped or bean-shaped. It is absent in erythrocytes and platelets. From above the core is covered nuclear envelope, which is represented by the outer and inner membrane. At the core is nucleoplasm, which is a gel-like substance and contains chromatin and nucleolus.

Rice. 2. Scheme of the ultramicroscopic structure of the cell
(according to M. R. Sapin, G. L. Bilich, 1989):
1 - cytolemma (plasma membrane); 2 - pinocytic vesicles; 3 - centrosome ( cell center, cytocenter); 4 - hyaloplasm; 5 - endoplasmic reticulum (a - membranes of the endoplasmic reticulum, b - ribosomes); 6- nucleus; 7 - connection of the perinuclear space with the cavities of the endoplasmic reticulum; 8 - nuclear pores; 9 - nucleolus; 10 - intracellular reticular apparatus (Golgi complex); 11- secretory vacuoles; 12- mitochondria; 13 - lysosomes; 14-three successive stages of phagocytosis; 15 - connection of the cell membrane (cytolemma) with the membranes of the endoplasmic reticulum

The core surrounds cytoplasm, which includes hyaloplasm, organelles and inclusions.
Hyaloplasm is the main substance of the cytoplasm, it is involved in metabolic processes cells, contains proteins, polysaccharides, nucleic acid, etc.
Permanent parts of a cell that have a specific structure and perform biochemical functions are called organelles. These include the cell center, mitochondria, the Golgi complex, the endoplasmic (cytoplasmic) reticulum.
Cell Center usually located near the nucleus or Golgi complex, consists of two dense formations - centrioles, which are part of the spindle of a moving cell and form cilia and flagella.
Mitochondria have the form of grains, threads, sticks, are formed from two membranes - internal and external. The length of the mitochondria ranges from 1 to 15 microns, the diameter is from 0.2 to 1.0 microns. The inner membrane forms folds (crystals) in which enzymes are located. In mitochondria, the breakdown of glucose, amino acids, the oxidation of fatty acids, the formation of ATP (adenosine triphosphoric acid) - the main energy material.
Golgi complex (intracellular reticular apparatus) has the appearance of bubbles, plates, tubes located around the nucleus. Its function is to transport substances, their chemical processing and removal of the products of its vital activity outside the cell.
Endoplasmic (cytoplasmic) reticulum It is formed from an agranular (smooth) and a granular (granular) network. Agranular Endoplasmic reticulum It is formed mainly by small cisterns and tubules with a diameter of 50-100 nm, which are involved in the metabolism of lipids and polysaccharides. The granular endoplasmic reticulum consists of plates, tubules, tanks, to the walls of which small formations are adjacent - ribosomes that synthesize proteins.
Cytoplasm also has constant accumulations of individual substances, which are called inclusions of the cytoplasm and have a protein, fat and pigment nature.
The cell, as part of a multicellular organism, performs the main functions: the assimilation of incoming substances and their splitting with the formation of energy necessary to maintain the vital activity of the organism. Cells also have irritability (motor reactions) and are able to multiply by division. Cell division can be indirect (mitosis) or reductional (meiosis).
Mitosis is the most common form of cell division. It consists of several stages - prophase, metaphase, anaphase and telophase. Simple (or direct) cell division - amitosis - is rare, in cases where the cell is divided into equal or unequal parts. Meiosis - a form of nuclear division, in which the number of chromosomes in a fertilized cell is halved and a rearrangement of the cell's gene apparatus is observed. The period from one cell division to another is called its life cycle.

fabrics

The cell is part of the tissue that makes up the body of humans and animals.
Textile - it is a system of cells and extracellular structures united by the unity of origin, structure and functions.
As a result of the interaction of the organism with the external environment, which has developed in the process of evolution, four types of tissues have appeared with certain functional features: epithelial, connective, muscle and nervous.
Each organ is made up of various tissues that are closely related. For example, the stomach, intestines, and other organs consist of epithelial, connective, smooth muscle, and nervous tissues.
The connective tissue of many organs forms the stroma, and the epithelial tissue forms the parenchyma. The function of the digestive system cannot be fully performed if its muscular activity is impaired.
Thus, the various tissues that make up a particular organ ensure the performance of the main function of this organ.

epithelial tissue

Epithelial tissue (epithelium) covers the entire outer surface of the body of humans and animals, lines the mucous membranes of hollow internal organs (stomach, intestines, urinary tract, pleura, pericardium, peritoneum) and is part of the endocrine glands. Allocate integumentary (superficial) and secretory (glandular) epithelium. Epithelial tissue is involved in the metabolism between the body and the environment, performs a protective function (skin epithelium), functions of secretion, absorption (intestinal epithelium), excretion (kidney epithelium), gas exchange (lung epithelium), and has a great regenerative capacity.
Depending on the number of cell layers and the shape of individual cells, epithelium is distinguished multilayer - keratinized and non-keratinized, transition and single layer - simple columnar, simple cubic (flat), simple squamous (mesothelium) (Fig. 3).
AT squamous epithelium the cells are thin, compacted, contain little cytoplasm, the discoid nucleus is in the center, its edge is uneven. The squamous epithelium lines the alveoli of the lungs, the walls of capillaries, blood vessels, cavities of the heart, where, due to its thinness, it diffuses various substances, reduces the friction of flowing fluids.
cuboidal epithelium lines the ducts of many glands, and also forms the tubules of the kidneys, performs a secretory function.
Columnar epithelium consists of tall and narrow cells. It lines the stomach, intestines, gallbladder, renal tubules, and is also part of the thyroid gland.

Rice. 3. Different kinds epithelium:
BUT - single layer flat; B - single layer cubic; AT - cylindrical; G-single-layer ciliated; D-multigrade; E - multilayer keratinizing

Cells ciliated epithelium usually have the shape of a cylinder, with many cilia on the free surfaces; lines the oviducts, the ventricles of the brain, the spinal canal and the respiratory tract, where it provides the transport of various substances.
Stratified epithelium lines the urinary tract, trachea, respiratory tract and is part of the mucous membrane of the olfactory cavities.
Stratified epithelium consists of several layers of cells. It lines the outer surface of the skin, the mucous membrane of the esophagus, the inner surface of the cheeks, and the vagina.
transitional epithelium located in those organs that are subject to strong stretching (bladder, ureter, renal pelvis). The thickness of the transitional epithelium prevents urine from entering the surrounding tissues.
glandular epithelium makes up the bulk of those glands in which epithelial cells are involved in the formation and release of substances necessary for the body.
There are two types of secretory cells - exocrine and endocrine. exocrine cells secrete on the free surface of the epithelium and through the ducts into the cavity (stomach, intestines, respiratory tract, etc.). Endocrine called glands, the secret (hormone) of which is secreted directly into the blood or lymph (pituitary, thyroid, thymus, adrenal glands).
By structure, exocrine glands can be tubular, alveolar, tubular-alveolar.

Connective tissue

The articles contain scientific and popular science information. The sections include such topics as the structure of the body (cellular level), diseases associated with dysfunctions of organs and other components, anatomy of organs, systems, and apparatuses. The structure and operation of each system is carefully described and provided with detailed illustrations, some systems are illustrated schematically, from an anatomical or histological point of view.

Each drawing or diagram contains an explanation of the work of a particular organ or system, taking into account the fundamental principles histology, anatomy and physiology. The mechanisms of functioning of the organism as a whole are also indicated, which allow it, while developing independently, at the same time to remain inextricably linked with the environment.

The structure and functions of cells, tissues, internal organs and systems

Materials about cells, tissues and organs of the human body are of great importance on the site. Analyzing in detail the structure of one or another structure of the human body, we understand the components of the sciences more deeply and more extensively, and as a result we can look at the human body as a whole.

Books and textbooks

The new section of the site is books and textbooks on natural and near-natural sciences and disciplines among which are manuals on anatomy, physiology, histology, psychophysiology, neurology, otorhinolaryngology, ophthalmology, pediatrics, traumatology, books about the human brain and neurosis, literature for obstetricians, dentists, paramedics, and many other sections.

Pictures, drawings and diagrams of human anatomy

Another new section of the site was a section with various drawings and diagrams of internal organs and human systems. These graphic materials are designed to help in the study of human anatomy, allowing you to visually familiarize yourself with the structures of the human body. Pictures, if possible, are distributed by organ systems, some drawings and diagrams are left without a category or may refer to several systems at once. Examples include the structure of the spleen, which is not only a hematopoietic organ, but also provides immune function.

Interesting facts about internal organs and systems

〄 The human brain contains a huge amount of water. Despite its complex structure, 80% of the human brain is water;

〄 The brain itself does not experience pain, unlike the tissues that surround it. This is due to the elementary absence of receptors in the tissues of the organ;

〄 Neurons are not the same and, at least, are divided into types, and from this it follows that information also moves along their processes at different speeds;

〄 The thesis that neurons do not recover is still controversial, however, the growth of nerve cells throughout our life remains a reliable fact;

〄 The blood vessels form a huge network, supplying nourishment to the multiple cells of the human body. If it were possible to stretch this network in one line, then such a single "vessel" would be enough to go around the Earth 2.5 times;

〄 The longest organ in our body is the small intestine;

〄 Another unusual property of our brain is its excessive love for oxygen. Of all the oxygen that the human body receives, 20% is taken by the brain. This explains and confirms the high sensitivity of the body to the lack of supplies;

〄 And for lovers of fountains, there is a very famous fact, and yes, we are talking about the heart - an organ that creates such a strong pressure that it may well be enough for a bloody fountain 9 meters high;

〄 When you were born, you had much more bones than now, namely, about a third more. But you can stop panicking, you didn’t lose the bones, they simply and prosaically grew together. Now there are about 206 of them in your body, well, give or take a few;

〄 A long time ago, there was a rumor that if you separate the head from the human body, then it can still remain conscious for about 15-20 seconds. Similar data has been presented since the time of executions, when the head of the executed could blink for a few more seconds after being cut off;

〄 In addition to children, debts or a growing business, after death we are quite capable of leaving 3 or even 4 kg. ashes, it's just a matter of cremation;

〄 Despite the oxygen voraciousness of the brain, it consumes not so much energy, namely, like a 10-watt light bulb. Economical and useful;

〄 Without saliva, we are not able to dissolve food, and therefore we cannot taste it;

〄 The approximate speed of travel of a nerve impulse from and to the brain is 273 km per hour;

〄 Fingerprints are an integral and unique anatomical characteristic of every human being. Registration of prints is completed in the child by the 6th month of pregnancy;

The main human need is the preservation of life and health. A healthy person is one who is free from disease and physical defects. In order to maintain health for as long as possible, it is necessary to study your body, to know what processes are going on inside, to study the factors and conditions that cause pathological changes.

They do it scientific disciplines who are researching human body develop prevention and treatment of diseases. There are 2 main areas: anatomy and physiology.

What is anatomy

Anatomy is a science that studies the structure of the body, organs and systems as a whole.

The discipline originated in ancient Greece BC. The name came from Greek word"anatom", when translated means "dissection".

In those days, the study of the human body was carried out by opening dead body. The first to conduct such experiments on animals was the scientist Alkemon, in order to study the structure of internal organs.

Hippocrates described the bones of the skull, the structure of the vertebrae, ribs, internal organs. This served as a powerful impetus for the study of the discipline in the future. Today, anatomy has several branches:

• normal anatomy- the science of a healthy body;
• pathological anatomy- a discipline that explores deviations from the norm, pathological changes in organs and systems;
• topographic anatomy studies layer-by-layer anatomical regions, the projection of organs on the skin ( holotopy), the location of organs relative to each other ( syntopy), relation to the skeleton ( skeletopy), blood supply, innervation and lymph outflow in normal and pathological conditions.

What is physiology

normal physiology explores the functions and processes of a healthy body. pathological physiology studies how the processes of vital activity change with any pathology, the factors leading to the disease, the pathogenesis of these phenomena.

It is generally accepted that physiology officially arose in 1628. when William Harvey (an English physician) published his treatise, in which he described the presence of large and small circles of blood circulation and the effect of the heart on the circulatory system.

Types of physiology:

• Age, which explores the vital activity of the human body, the formation, development and extinction of its functions;
• labor physiology studies professional factors that affect life processes;
• aviation considers changes in the reactions of the body in conditions of low atmospheric pressure and space;
• ecological detects and studies the reactions in the body with changes in climate and geographic environment, an increase in endurance to adverse factors;
• evolutionary studies the processes of physiology, their mechanisms of regulation and development, similarities in organisms that are at different evolutionary stages.

Human anatomy and physiology are inseparable from each other. A set of cells form a tissue, the tissue turns into an organ, the organs turn into systems. The structure of organs is directly connected with their functions.

For example, the stomach consists of a mucous, submucosal, muscular, serous layer. Its main functions are the mixing of the food eaten and its splitting, for further movement through the gastrointestinal tract. The muscle layer contracts, when food enters, the food is mixed and rubbed to a thick consistency. The cells of the mucous layer secrete pepsin and hydrochloric acid. Pepsin is needed to convert proteins into polypeptides and amino acids, and hydrochloric acid forms the necessary acidity for the action of proteolysis enzymes and kills bacteria.

Having knowledge about the structure of an organ, one can understand its functional abilities, and vice versa, understanding the functions of an organ, one can explain its structure.

Based on the knowledge of human anatomy and physiology, it is possible to solve the problems of maintaining health and well-being, to carry out preventive and therapeutic measures.

For example, with atherosclerosis of the coronary vessels, an atherosclerotic plaque appears on the wall of the arteries, which leads to circulatory disorders, hypoxia and the development of coronary heart disease, its adverse consequences. One of the reasons for the development of this plaque is elevated level cholesterol. It is with the help of knowledge of the pathogenesis of the disease that it is possible to prevent the development of the disease by reducing foods containing saturated fats in the diet (sausages and flour products, cakes).

Anatomy and physiology are two pillars on which the entire medical industry is built.