That is why the science of mechanics is so noble
and more useful than all other sciences, which,
as it turns out, all living beings,
having the ability to move,
act according to its laws.

Leonardo da Vinci

Know yourself!

The human locomotor system is a self-propelled mechanism consisting of 600 muscles, 200 bones, and several hundred tendons. These numbers are approximate because some bones (e.g., spinal column, rib cage) are fused together, and many muscles have multiple heads (e.g., biceps brachii, quadriceps femoris) or are divided into multiple bundles (deltoid, pectoralis major, rectus abdominis, latissimus dorsi and many others). It is believed that human motor activity is comparable in complexity to human brain- the most perfect creation of nature. And just as the study of the brain begins with the study of its elements (neurons), so in biomechanics, first of all, the properties of the elements of the motor apparatus are studied.

The motor system consists of links. Linkcalled the part of the body located between two adjacent joints or between a joint and the distal end. For example, the parts of the body are: hand, forearm, shoulder, head, etc.

GEOMETRY OF HUMAN BODY MASSES

The geometry of masses is the distribution of masses between the links of the body and within the links. The geometry of masses is quantitatively described by mass-inertial characteristics. The most important of them are mass, radius of inertia, moment of inertia and coordinates of the center of mass.

Weight (T)is the amount of substance (in kilograms),contained in the body or individual link.

At the same time, mass is a quantitative measure of the inertia of a body in relation to the force acting on it. The greater the mass, the more inert the body and the more difficult it is to remove it from a state of rest or change its movement.

Mass determines the gravitational properties of a body. Body weight (in Newtons)

acceleration of a freely falling body.

Mass characterizes the inertia of a body during translational motion. During rotation, inertia depends not only on mass, but also on how it is distributed relative to the axis of rotation. The greater the distance from the link to the axis of rotation, the greater the contribution of this link to the inertia of the body. A quantitative measure of the inertia of a body during rotational motion is moment of inertia:

Where R in — radius of inertia - the average distance from the axis of rotation (for example, from the axis of a joint) to the material points of the body.

Center of mass is the point where the lines of action of all forces that lead the body to translational motion and do not cause rotation of the body intersect. In a gravitational field (when gravity acts), the center of mass coincides with the center of gravity. The center of gravity is the point to which the resultant forces of gravity of all parts of the body are applied. The position of the overall center of mass of the body is determined by where the centers of mass of the individual links are located. And this depends on the posture, i.e. on how the parts of the body are located relative to each other in space.

There are about 70 links in the human body. But so detailed description mass geometry is most often not required. For majority decision practical problems a 15-link model is enough human body(Fig. 7). It is clear that in the 15-link model, some links consist of several elementary links. Therefore, it is more correct to call such enlarged links segments.

Numbers in Fig. 7 are true for the “average person” and are obtained by averaging the results of a study of many people. Individual characteristics of a person, and primarily the mass and length of the body, influence the geometry of the masses.

Rice. 7. 15 - link model of the human body: on the right - the method of dividing the body into segments and the mass of each segment (in% of body weight); on the left - locations of the centers of mass of the segments (in % of the segment length) - see table. 1 (according to V. M. Zatsiorsky, A. S. Aruin, V. N. Seluyanov)

V. N. Seluyanov established that the masses of body segments can be determined using the following equation:

Where m X — the mass of one of the body segments (kg), for example, foot, lower leg, thigh, etc.;m— total body weight (kg);H— body length (cm);B 0, B 1, B 2— coefficients of the regression equation, they are different for different segments(Table 1).

Note. The coefficient values ​​are rounded and are correct for an adult male.

In order to understand how to use Table 1 and other similar tables, let’s calculate, for example, the mass of the hand of a person whose body weight is 60 kg and whose body length is 170 cm.

Table 1

Equation coefficients for calculating the mass of body segments by mass (T) and body length(s)

Segments	Equation coefficients
	B 0	IN 1	AT 2
Foot Shin Hip Brush Forearm Shoulder Head Upper body Mid torso Lower torso	—0,83 —1,59 —2,65 —0,12 0,32 0,25 1,30 8,21 7,18 —7,50	0,008 0,036 0,146 0,004 0,014 0,030 0,017 0,186 0,223 0,098	0,007 0,012 0,014 0,002 —0,001 —0,003 0,014 —0,058 —0,066 0,049

Brush weight = - 0.12 + 0.004x60+0.002x170 = 0.46 kg. Knowing what the masses and moments of inertia of the body links are and where their centers of mass are located, you can solve many important practical problems. Including:

- determine the quantity movements, equal to the product of body mass and its linear speed(m·v);

— determine kinetic moment, equal to the product of the moment of inertia of the body and the angular velocity(J w ); it should be taken into account that the values ​​of the moment of inertia relative to different axes are not the same;

- assess whether it is easy or difficult to control the speed of a body or an individual link;

— determine the degree of body stability, etc.

From this formula it is clear that during rotational motion about the same axis, the inertia of the human body depends not only on mass, but also on posture. Let's give an example.

In Fig. Figure 8 shows a figure skater performing a spin. In Fig. 8, A the athlete rotates quickly and makes about 10 revolutions per second. In the pose shown in Fig. 8, B, the rotation slows down sharply and then stops. This happens because, by moving her arms to the sides, the skater makes her body more inert: although the mass ( m ) remains the same, the radius of gyration (R in ) and therefore the moment of inertia.

Rice. 8. Slowing down rotation when changing pose:A -smaller; B - a large value of the radius of inertia and moment of inertia, which is proportional to the square of the radius of inertia (I=m R in)

Another illustration of what has been said can be a comic problem: what is heavier (more precisely, more inert)—a kilogram of iron or a kilogram of cotton wool? During forward motion, their inertia is the same. When moving in a circular motion, it is more difficult to move the cotton. Its material points are further away from the axis of rotation, and therefore the moment of inertia is much greater.

BODY LINKS AS LEVERS AND PENDULUMS

Biomechanical links are a kind of levers and pendulums.

As you know, levers are of the first kind (when forces are applied on opposite sides of the fulcrum) and of the second kind. An example of a second-class lever is shown in Fig. 9, A: gravitational force(F 1)and the opposing force of muscle traction(F 2) applied on one side of the fulcrum, located in this case at the elbow joint. There are a majority of such levers in the human body. But there are also levers of the first kind, for example the head (Fig. 9, B) and the pelvis in the main stance.

Exercise: find the lever of the first kind in fig. 9, A.

The lever is in equilibrium if the moments of the opposing forces are equal (see Fig. 9, A):

F 2 — traction force of the biceps brachii muscle;l 2 —a short lever arm equal to the distance from the tendon attachment to the axis of rotation; α is the angle between the direction of the force and the perpendicular to the longitudinal axis of the forearm.

The lever device of the motor apparatus gives a person the opportunity to perform long throws, strong blows etc. But nothing in the world comes for free. We gain in speed and power of movement at the cost of increasing the strength of muscle contraction. For example, in order to move a load weighing 1 kg (i.e. with a gravity force of 10 N) by bending the arm at the elbow joint as shown in Fig. 9, L, the biceps brachii muscle should develop a force of 100-200 N.

The “exchange” of force for speed is more pronounced, the greater the ratio of the lever arms. Let us illustrate this important point with an example from rowing (Fig. 10). All points of the oar-body moving around an axis have the samesame angular velocity

But their linear speeds are not the same. Linear speed(v)the higher, the larger the radius of rotation (r):

Therefore, to increase speed, you need to increase the radius of rotation. But then you will have to increase the force applied to the oar by the same amount. That is why it is more difficult to row with a long oar than a short one, throwing a heavy object over a long distance is more difficult than over a short distance, etc. Archimedes, who led the defense of Syracuse from the Romans and invented lever devices for throwing stones, knew about this.

A person's arms and legs can make oscillatory movements. This makes our limbs look like pendulums. The least energy expenditure for moving the limbs occurs when the frequency of movements is 20-30% greater than the frequency of natural vibrations of the arm or leg:

where (g= 9.8 m/s 2 ; l - the length of the pendulum, equal to the distance from the point of suspension to the center of mass of the arm or leg.

This 20-30% is explained by the fact that the leg is not a single-link cylinder, but consists of three segments (thigh, lower leg and foot). Please note: the natural frequency of oscillations does not depend on the mass of the swinging body, but decreases as the length of the pendulum increases.

By making the frequency of steps or strokes when walking, running, swimming, etc. resonant (i.e., close to the natural frequency of vibration of the arm or leg), it is possible to minimize energy costs.

It has been noted that with the most economical combination of frequency and length of steps or strokes, a person demonstrates significantly increased physical performance. It is useful to take this into account not only when training athletes, but also when conducting physical education classes in schools and health groups.

An inquisitive reader may ask: what explains the high efficiency of movements performed at a resonant frequency? This happens because the oscillatory movements of the upper and lower extremities are accompanied by recuperation mechanical energy (from lat. recuperatio - receipt again or reuse). Simplest form recovery - the transition of potential energy into kinetic, then again into potential, etc. (Fig. 11). At a resonant frequency of movements, such transformations are carried out with minimal energy losses. This means that metabolic energy, once created in muscle cells and converted into mechanical energy, is used repeatedly - both in this cycle of movements and in subsequent ones. And if so, then the need for an influx of metabolic energy decreases.

Rice. eleven. One of the options for energy recovery during cyclic movements: the potential energy of the body (solid line) transforms into kinetic energy (dotted line), which is again converted into potential and contributes to the transition of the gymnast’s body to the upper position; the numbers on the graph correspond to the athlete's numbered poses

Thanks to energy recovery, performing cyclic movements at a pace close to the resonant frequency of limb oscillations— effective method conservation and accumulation of energy. Resonant vibrations contribute to the concentration of energy, and in the world of inanimate nature they are sometimes unsafe. For example, there are known cases of a bridge being destroyed when a military unit was walking across it, clearly taking steps. Therefore, you are supposed to walk out of step on the bridge.

MECHANICAL PROPERTIES OF BONES AND JOINTS

Mechanical properties of bones determined by their various functions; In addition to motor, they perform protective and support functions.

The bones of the skull, chest and pelvis protect the internal organs. Support function bones are performed by the bones of the limbs and spine.

The bones of the legs and arms are oblong and tubular. The tubular structure of bones provides resistance to significant loads and at the same time reduces their mass by 2-2.5 times and significantly reduces moments of inertia.

There are four types of mechanical effects on bone: tension, compression, bending and torsion.

With a tensile longitudinal force, the bone can withstand a stress of 150 N/mm 2 . This is 30 times more than the pressure that destroys a brick. It has been established that the tensile strength of bone is higher than that of oak and almost equal to that of cast iron.

When compressed, bone strength is even higher. Thus, the most massive bone, the tibia, can withstand the weight of 27 people. The maximum compression force is 16,000–18,000 N.

When bending, human bones also withstand significant loads. For example, a force of 12,000 N (1.2 t) is not enough to break femur. This type of deformation is widely found in Everyday life, and in sports practice. For example, segments upper limb deformed by bending when maintaining the “cross” position while hanging on the rings.

When we move, bones not only stretch, compress, and bend, but also twist. For example, when a person walks, the moments of torsional forces can reach 15 Nm. This value is several times less than the tensile strength of bones. Indeed, to destroy, for example, the tibia, the moment of twisting force must reach 30-140 Nm (Information about the magnitude of forces and moments of forces leading to bone deformation is approximate, and the figures are apparently underestimated, since they were obtained mainly from cadaveric material. But they also indicate a multiple safety margin of the human skeleton. In some countries, intravital determination of bone strength is practiced. Such research is well paid, but leads to injury or death of testers and is therefore inhumane).

Table 2

The magnitude of the force acting on the head of the femur
(by X. A. Janson, 1975, revised)

Type of motor activity	Magnitude of force (according to type of motor activityrelation to body gravity)
seat	0,08
Standing on two legs	0,25
Standing on one leg	2,00
Walking on a flat surface	1,66
Ascent and descent on an inclined surface	2,08
Fast walk	3,58

The permissible mechanical loads are especially high for athletes, because regular training leads to working hypertrophy of the bones. It is known that weightlifters have thicker bones in their legs and spine, while football players have outer part metatarsal bones, in tennis players - forearm bones, etc.

Mechanical properties of joints depend on their structure. The articular surface is moistened by synovial fluid, which, as in a capsule, is stored by the joint capsule. Synovial fluid reduces the coefficient of friction in the joint by approximately 20 times. The nature of the action of the “squeezable” lubricant is striking, which, when the load on the joint decreases, is absorbed by the spongy formations of the joint, and when the load increases, it is squeezed out to wet the surface of the joint and reduce the coefficient of friction.

Indeed, the magnitude of the forces acting on the articular surfaces is enormous and depends on the type of activity and its intensity (Table 2).

Note. Even higher are the forces acting on knee-joint; with a body weight of 90 kg they reach: when walking 7000 N, when running 20000 N.

The strength of joints, like the strength of bones, is not unlimited. Thus, the pressure in the articular cartilage should not exceed 350 N/cm 2 . At higher pressures, lubrication of the articular cartilage ceases and the risk of mechanical abrasion increases. This should be taken into account especially when conducting hiking trips (when a person carries a heavy load) and when organizing recreational activities for middle-aged and elderly people. After all, it is known that with age, lubrication of the joint capsule becomes less abundant.

BIOMECHANICS OF MUSCLES

Skeletal muscles are the main source of mechanical energy in the human body. They can be compared to an engine. What is the operating principle of such a “living engine” based on? What activates a muscle and what properties does it exhibit? How do muscles interact with each other? Finally, what are the best modes of muscle function? You will find answers to these questions in this section.

Biomechanical properties of muscles

These include contractility, as well as elasticity, rigidity, strength and relaxation.

Contractility is the ability of a muscle to contract when excited. As a result of contraction, the muscle shortens and a traction force occurs.

To talk about the mechanical properties of a muscle, we will use a model (Fig. 12), in which connective tissue formations (parallel elastic component) have a mechanical analogue in the form of a spring(1). Connective tissue formations include: the membrane of muscle fibers and their bundles, sarcolemma and fascia.

When a muscle contracts, transverse actin-myosin bridges are formed, the number of which determines the force of muscle contraction. Actin-myosin bridges of the contractile component are depicted on the model in the form of a cylinder in which the piston moves(2).

An analogue of a sequential elastic component is a spring(3), connected in series with the cylinder. It models the tendon and those myofibrils (contractile filaments that make up the muscle) that are this moment do not participate in the reduction.

According to Hooke's law for a muscle, its elongation nonlinearly depends on the magnitude of the tensile force (Fig. 13). This curve (called “strength - length”) is one of the characteristic relationships that describe the patterns of muscle contraction. Another characteristic “force-velocity” relationship is named after the famous English physiologist Hill’s curve who studied it (Fig. 14) (This is how we call this important dependence today. In fact, A. Hill studied only overcoming movements (the right side of the graph in Fig. 14). The relationship between force and speed during yielding movements was first studied by Abbot. ).

Strength muscle is assessed by the magnitude of the tensile force at which the muscle ruptures. The limiting value of the tensile force is determined by the Hill curve (see Fig. 14). Force at which muscle rupture occurs (in terms of 1 mm 2 its cross section), ranges from 0.1 to 0.3 N/mm 2 . For comparison: the tensile strength of the tendon is about 50 N/mm 2 , and fascia is about 14 N/mm 2 . The question arises: why does a tendon sometimes tear, but the muscle remains intact? Apparently, this can happen with very fast movements: the muscle has time to absorb shock, but the tendon does not.

Relaxation - a property of a muscle manifested in a gradual decrease in traction force at a constant lengthmuscles. Relaxation manifests itself, for example, when jumping and jumping up, if a person pauses during a deep squat. The longer the pause, the lower the repulsion force and the jumping height.

Modes of contraction and types of muscle work

Muscles attached by tendons to bones function in isometric and anisometric modes (see Fig. 14).

In the isometric (holding) mode, the length of the muscle does not change (from the Greek “iso” - equal, “meter” - length). For example, in the isometric contraction mode, the muscles of a person who has pulled himself up and holds his body in this position work. Similar examples: “Azaryan cross” on the rings, holding the barbell, etc.

On the Hill curve, the isometric mode corresponds to the magnitude of the static force(F 0),at which the speed of muscle contraction is zero.

It has been noted that the static strength exhibited by an athlete in the isometric mode depends on the mode of previous work. If the muscle functioned in a inferior mode, thenF 0more than in the case when overcoming work was performed. That is why, for example, the “Azaryan cross” is easier to perform if the athlete comes into it from the top position, rather than from the bottom.

During anisometric contraction, the muscle shortens or lengthens. The muscles of a runner, swimmer, cyclist, etc. function in anisometric mode.

The anisometric mode has two varieties. In overcoming mode, the muscle shortens as a result of contraction. And in the yielding mode, the muscle is stretched by an external force. For example, calf muscle The sprinter functions in a yielding mode when the leg interacts with the support in the depreciation phase, and in an overcoming mode in the repulsion phase.

The right side of the Hill curve (see Fig. 14) displays the patterns of overcoming work, in which an increase in the speed of muscle contraction causes a decrease in traction force. And in the inferior mode, the opposite picture is observed: an increase in the speed of muscle stretching is accompanied by an increase in traction force. This is the cause of numerous injuries in athletes (eg, Achilles tendon rupture in sprinters and long jumpers).

Rice. 15. The power of muscle contraction depending on the strength and speed exerted; the shaded rectangle corresponds to the maximum power

Group interaction of muscles

There are two cases of group interaction of muscles: synergism and antagonism.

Synergistic musclesmove body parts in one direction. For example, in bending the arm at the elbow joint, the biceps brachii, brachialis and brachioradialis muscles, etc. are involved. The result of the synergistic interaction of the muscles is an increase in the resulting force of action. But the significance of muscle synergism does not end there. In the presence of an injury, as well as in the case of local fatigue of a muscle, its synergists ensure the performance of a motor action.

Antagonist muscles(as opposed to synergistic muscles) have multidirectional effects. So, if one of them does overcoming work, then the other does inferior work. The existence of antagonist muscles ensures: 1) high precision of motor actions; 2) reduction of injuries.

Power and efficiency of muscle contraction

As the speed of muscle contraction increases, the traction force of the muscle operating in the overcoming mode decreases according to the hyperbolic law (see. rice. 14). It is known that mechanical power is equal to the product of force and speed. There are strengths and speeds at which the power of muscle contraction is greatest (Fig. 15). This mode occurs when both force and speed are approximately 30% of their maximum possible values.

Has it ever seemed strange to you that you have been living for decades, but know absolutely nothing about your own body? Or that you found yourself taking an exam on human anatomy, but did not prepare for it at all. In both cases, you need to catch up on lost knowledge and get to know the human organs better. It is better to see their location in pictures - clarity is very important. Therefore, we have collected pictures for you in which the location of human organs is easily traced and labeled.

If you like games with human internal organs, be sure to try it on our website.

To enlarge any picture, click on it and it will open in full size. This way you can read the fine print. So let's start at the top and work our way down.

Human organs: location in pictures.

Brain

The human brain is the most complex and least studied human organ. He controls all other organs and coordinates their work. In fact, our consciousness is the brain. Despite little knowledge, we still know the location of its main sections. This picture describes in detail the anatomy of the human brain.

Larynx

The larynx allows us to make sounds, speech, singing. The structure of this cunning organ is shown in the picture.

Major organs, chest and abdominal organs

This picture shows the location of the 31 organs of the human body from the thyroid cartilage to the rectum. If you urgently need to look at the location of any organ in order to win an argument with a friend or take an exam, this picture will help.

The picture shows the location of the larynx, thyroid gland, trachea, pulmonary veins and arteries, bronchi, heart and pulmonary lobes. Not much, but very clear.

Schematic arrangement of human internal organs from trochea to Bladder shown in this picture. Due to its small size, it loads quickly, saving you time for peeking during the exam. But we hope that if you are studying to become a doctor, then you do not need the help of our materials.

A picture showing the location of human internal organs, which also shows the system of blood vessels and veins. The organs are beautifully depicted from an artistic point of view, some of them are signed. We hope that among those signed there are those you need.

A picture that details the location of the organs of the human digestive system and the pelvis. If you have a stomach ache, this picture will help you localize the source while it works Activated carbon, or while you ease your digestive system in convenience.

Location of the pelvic organs

If you need to know the location of the superior adrenal artery, bladder, psoas major muscle or any other organ abdominal cavity, then this picture will help you. It describes in detail the location of all organs of this cavity.

Human genitourinary system: location of organs in pictures

Everything you wanted to know about the genitourinary system of a man or woman is shown in this picture. Seminal vesicles, eggs, labia of all stripes and, of course, the urinary system in all its glory. Enjoy!

Male reproductive system

The study of the complex structure of the human body and the arrangement of internal organs is the study of human anatomy. Discipline helps us understand the structure of our body, which is one of the most complex on the planet. All its parts perform strictly defined functions and they are all interconnected. Modern anatomy is a science that distinguishes both what we observe visually and the structure of the human body hidden from the eyes.

What is human anatomy

This is the name of one of the sections of biology and morphology (along with cytology and histology), which studies the structure of the human body, its origin, formation, evolutionary development at a level above the cellular level. Anatomy (from the Greek Anatomia - cut, opening, dissection) studies what the external parts of the body look like. She also describes internal environment and microscopic structure of organs.

Isolating human anatomy from comparative anatomies All living organisms are conditioned by the presence of thinking. There are several main forms of this science:

1. Normal or systematic. This section studies the body of the “normal”, i.e. healthy person by tissues, organs, and their systems.
2. Pathological. This is a scientific and applied discipline that studies diseases.
3. Topographical or surgical. It is called this because it has practical significance for surgery. Complements descriptive human anatomy.

Normal anatomy

Extensive material has led to the complexity of studying the anatomy of the human body. For this reason, it became necessary to artificially divide it into parts - organ systems. They are considered normal, or systematic, anatomy. She breaks down the complex into simpler ones. Normal human anatomy studies the body in healthy condition. This is its difference from pathological. Plastic anatomy studies appearance. It is used to depict a human figure.

• topographical;
• typical;
• comparative;
• theoretical;
• age;
• X-ray anatomy.

Pathological human anatomy

This type of science, along with physiology, studies the changes that occur in the human body during certain diseases. Anatomical studies are carried out microscopically, which helps to identify pathological physiological factors in tissues, organs, and their combinations. The object in this case is the corpses of people who died from various diseases.

The study of the anatomy of a living person is carried out using harmless methods. This discipline is mandatory in medical universities. Anatomical knowledge here is divided into:

• general, reflecting methods of anatomical studies of pathological processes;
• particular ones, describing the morphological manifestations of individual diseases, for example, tuberculosis, cirrhosis, rheumatism.

Topographic (surgical)

This type of science developed as a result of the need for practical medicine. The doctor N.I. is considered its creator. Pirogov. Scientific human anatomy studies the arrangement of elements relative to each other, layer-by-layer structure, the process of lymph flow, and blood supply in a healthy body. This takes into account gender characteristics and changes associated with age-related anatomy.

Human anatomical structure

The functional elements of the human body are cells. Their accumulation forms the tissue from which all parts of the body are composed. The latter are combined in the body into systems:

1. Digestive. It is considered the most difficult. The organs of the digestive system are responsible for the process of digesting food.
2. Cardiovascular. The function of the circulatory system is to supply blood to all parts of the human body. This includes lymphatic vessels.
3. Endocrine. Its function is to regulate nervous and biological processes in the body.
4. Genitourinary. It differs in men and women and provides reproductive and excretory functions.
5. Intercession. Protects the insides from external influences.
6. Respiratory. Saturates blood with oxygen and converts it into carbon dioxide.
7. Musculoskeletal. Responsible for moving a person and maintaining the body in a certain position.
8. Nervous. Includes the spinal cord and brain, which regulate all body functions.

The structure of human internal organs

Section of anatomy that studies internal systems human is called splanchnology. These include respiratory, genitourinary and digestive. Each has characteristic anatomical and functional connections. They can be united by the common property of metabolism between the external environment and humans. In the evolution of the organism, it is believed that the respiratory system buds off from certain parts of the digestive tract.

Organs of the respiratory system

They ensure a continuous supply of oxygen to all organs and remove carbon dioxide from them. This system is divided into the upper and lower respiratory tract. The list of the first includes:

1. Nose. Produces mucus, which traps foreign particles when breathing.
2. Sinuses. Air-filled cavities in the lower jaw, sphenoid, ethmoid, frontal bones.
3. Throat. It is divided into the nasopharynx (provides air flow), the oropharynx (contains tonsils that have a protective function), and the hypopharynx (serves as a passage for food).
4. Larynx. Prevents food from entering the respiratory tract.

Another part of this system is the lower respiratory tract. They include organs chest cavity presented in the following small list:

1. Trachea. It starts after the larynx and extends down to the chest. Responsible for air filtration.
2. Bronchi. Similar in structure to the trachea, they continue to purify the air.
3. Lungs. Located on both sides of the heart in chest. Each lung is responsible for the vital process of exchanging oxygen with carbon dioxide.

Human abdominal organs

The abdominal cavity has a complex structure. Its elements are located in the center, left and right. According to human anatomy, the main organs in the abdominal cavity are as follows:

1. Stomach. Located on the left under the diaphragm. Responsible for the primary digestion of food and signals satiety.
2. The kidneys are located symmetrically at the bottom of the peritoneum. They perform the urinary function. The substance of the kidney consists of nephrons.
3. Pancreas. Located just below the stomach. Produces enzymes for digestion.
4. Liver. It is located on the right under the diaphragm. Removes poisons, toxins, removes unnecessary elements.
5. Spleen. Located behind the stomach, it is responsible for the immune system and ensures hematopoiesis.
6. Intestines. Located in the lower abdomen, it absorbs all useful substances.
7. Appendix. It is an appendage of the cecum. Its function is protective.
8. Gallbladder. Located below the liver. Accumulates incoming bile.

Genitourinary system

This includes the organs of the human pelvic cavity. There are significant differences in the structure of this part between men and women. They are located in organs that provide reproductive function. In general, the description of the structure of the pelvis includes information about:

1. Bladder. Collects urine before urination. Located below in front of the pubic bone.
2. Female genital organs. The uterus is located below the bladder, and the ovaries are slightly higher above it. They produce eggs responsible for reproduction.
3. Male genital organs. Prostate also located under the bladder, responsible for the production of secretory fluid. The testicles are located in the scrotum; they produce sex cells and hormones.

Human endocrine organs

System responsible for regulating activity human body through hormones - endocrine. Science distinguishes two devices in it:

1. Diffuse. Endocrine cells here are not concentrated in one place. Some functions are performed by the liver, kidneys, stomach, intestines and spleen.
2. Glandular. Includes the thyroid, parathyroid glands, thymus, pituitary gland, adrenal glands.

Thyroid and parathyroid glands

The largest endocrine gland is the thyroid. It is located on the neck in front of the trachea, on its lateral walls. The gland is partially adjacent to the thyroid cartilage and consists of two lobes and an isthmus necessary for their connection. The function of the thyroid gland is to produce hormones that promote growth, development, and regulate metabolism. Not far from it are the parathyroid glands, which have the following structural features:

1. Quantity. There are 4 of them in the body - 2 upper, 2 lower.
2. Place. Located on back surface lateral lobes of the thyroid gland.
3. Function. Responsible for the exchange of calcium and phosphorus (parathyroid hormone).

Anatomy of the thymus

The thymus, or thymus gland, is located behind the manubrium and part of the body of the sternum in the upper anterior region of the chest cavity. Represents two lobes connected loosely connective tissue. The upper ends of the thymus are narrower, so they extend beyond the chest cavity and reach the thyroid gland. In this organ, lymphocytes acquire properties that provide protective functions against cells foreign to the body.

Structure and functions of the pituitary gland

A small spherical or oval gland with a reddish tint is the pituitary gland. It is connected directly to the brain. The pituitary gland has two lobes:

1. Front. It affects the growth and development of the entire body as a whole, stimulates the activity of the thyroid gland, adrenal cortex, and gonads.
2. Rear. Responsible for enhancing the work of vascular smooth muscles, increases blood pressure, and affects the reabsorption of water in the kidneys.

Adrenal glands, gonads and endocrine pancreas

The paired organ located above the upper end of the kidney in the retroperitoneal tissue is the adrenal gland. On the anterior surface it has one or more grooves that act as gates for outgoing veins and incoming arteries. Functions of the adrenal glands: production of adrenaline in the blood, neutralization of toxins in muscle cells. Other elements of the endocrine system:

1. Sex glands. The testes contain interstitial cells responsible for the development of secondary sexual characteristics. The ovaries secrete folliculin, which regulates menstruation and affects the nervous state.
2. Endocrine part of the pancreas. It contains pancreatic islets that secrete insulin and glucagon into the blood. This ensures regulation of carbohydrate metabolism.

Musculoskeletal system

This system is a set of structures that provide support to parts of the body and help a person move in space. The entire apparatus is divided into two parts:

1. Osteoarticular. From a mechanical point of view, it is a system of levers that, as a result of muscle contraction, transmit forces. This part is considered passive.
2. Muscular. The active part of the musculoskeletal system is muscles, ligaments, tendons, cartilaginous structures, and synovial bursae.

Anatomy of bones and joints

The skeleton consists of bones and joints. Its functions are the perception of loads, the protection of soft tissues, and the implementation of movements. Bone marrow cells produce new blood cells. Joints are the points of contact between bones, between bones and cartilage. The most common type is synovial. Bones develop as a child grows, providing support for the entire body. They make up the skeleton. It contains 206 individual bones, made up of bone tissue and bone cells. All of them are located in the axial (80 pieces) and appendicular (126 pieces) skeleton.

The weight of bones in an adult is about 17-18% of body weight. According to the description of the structures of the skeletal system, its main elements are:

1. Scull. Consists of 22 connected bones, excluding only lower jaw. Functions of the skeleton in this part: protecting the brain from damage, supporting the nose, eyes, mouth.
2. Spine. Formed by 26 vertebrae. The main functions of the spine: protective, shock-absorbing, motor, supporting.
3. Rib cage. Includes the sternum, 12 pairs of ribs. They protect the chest cavity.
4. Limbs. This includes the shoulders, hands, forearms, hip bones, feet and legs. Provide basic motor activity.

The structure of the muscular skeleton

The human anatomy also studies the muscle apparatus. There is even a special section - myology. The main function of muscles is to provide a person with the ability to move. About 700 muscles are attached to the bones of the skeletal system. They make up about 50% of a person’s body weight. The main types of muscles are as follows:

1. Visceral. They are located inside organs and ensure the movement of substances.
2. Heart. Located only in the heart, it is necessary for pumping blood throughout the human body.
3. Skeletal. This type of muscle tissue is controlled by a person consciously.

Organs of the human cardiovascular system

The cardiovascular system includes the heart, blood vessels and about 5 liters of transported blood. Their main function is to transport oxygen, hormones, nutrients and cellular waste. This system works only due to the heart, which, while remaining at rest, pumps about 5 liters of blood throughout the body every minute. It continues to work even at night, when most of the rest of the body is resting.

Anatomy of the heart

This organ has a muscular hollow structure. The blood in it flows into the venous trunks and is then driven into the arterial system. The heart consists of 4 chambers: 2 ventricles, 2 atria. The left parts act as the arterial heart, and the right parts act as the venous heart. This division is based on the blood in the chambers. In human anatomy, the heart is a pumping organ, since its function is to pump blood. There are only 2 circles of blood circulation in the body:

• small, or pulmonary, transporting venous blood;
• large, carrying oxygenated blood.

Vessels of the pulmonary circle

The pulmonary circulation moves blood from the right side of the heart towards the lungs. There it is filled with oxygen. This is the main function of the vessels of the pulmonary circle. Then the blood returns back, but to the left half of the heart. The pulmonary circuit is supported by the right atrium and right ventricle - for it they are pumping chambers. This circulation includes:

• right and left pulmonary arteries;
• their branches are arterioles, capillaries and precapillaries;
• venules and veins that merge into 4 pulmonary veins, which flow into the left atrium.

Arteries and veins of the systemic circulation

The bodily, or systemic, circulation in human anatomy is designed to deliver oxygen and nutrients to all tissues. Its function is the subsequent removal of carbon dioxide from them with metabolic products. The circle begins in the left ventricle - from the aorta, which carries arterial blood. Next comes the division into:

1. Arteries. They go to all the insides except the lungs and heart. Contains nutrients.
2. Arterioles. These are small arteries that carry blood to the capillaries.
3. Capillaries. In them, the blood releases nutrients with oxygen, and in return takes in carbon dioxide and metabolic products.
4. Venules. These are return vessels that ensure the return of blood. Similar to arterioles.
5. Vienna. They merge into two large trunks - the superior and inferior vena cava, which flow into the right atrium.

Anatomy of the structure of the nervous system

Sense organs, nervous tissue and cells, spinal cord and brain - this is what the nervous system consists of. Their combination provides control of the body and the interconnection of its parts. The central nervous system is the control center consisting of the brain and spinal cord. It is responsible for evaluating information coming from outside and making certain decisions by a person.

Location of human organs CNS

Human anatomy says that the main function of the central nervous system is to carry out simple and complex reflexes. The following important bodies are responsible for them:

1. Brain. Located in the brain part of the skull. It consists of several sections and 4 communicating cavities - the cerebral ventricles. performs higher mental functions: consciousness, voluntary actions, memory, planning. It also supports breathing, heart rate, digestion and blood pressure.
2. Spinal cord. Located in the spinal canal, it is a white cord. It has longitudinal grooves on the anterior and posterior surfaces, and the spinal canal in the center. The spinal cord consists of white (conductor of nerve signals from the brain) and gray (creates reflexes to stimuli) matter.

Watch a video about the structure of the human brain.

Functioning of the peripheral nervous system

This includes elements nervous system located outside the spinal cord and brain. This part stands out conditionally. It includes the following:

1. Spinal nerves. Each person has 31 pairs. The posterior branches of the spinal nerves run between the transverse processes of the vertebrae. They innervate the back of the head and deep back muscles.
2. Cranial nerves. There are 12 pairs. Innervates the organs of vision, hearing, smell, glands of the oral cavity, teeth and facial skin.
3. Sensory receptors. These are specific cells that perceive irritation from the external environment and convert it into nerve impulses.

Human anatomical atlas

The structure of the human body is described in detail in the anatomical atlas. The material in it shows the body as a whole, consisting of individual elements. Many encyclopedias were written by various medical scientists who studied human anatomy. These collections contain visual diagrams of the placement of organs of each system. This makes it easier to see the relationship between them. In general, an anatomical atlas is a detailed description of the internal structure of a person.

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Attention! The information presented in the article is for informational purposes only. The materials in the article do not encourage self-treatment. Only a qualified doctor can make a diagnosis and make recommendations for treatment based on the individual characteristics of a particular patient.

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In the game "Who Wants to Be a Millionaire?" today, October 7, 2017, the twelfth question for the players of the first part of the game turned out to be difficult. The question concerned a model of the human body - a visual aid for future doctors. The correct answer is highlighted in blue and bold.

What is the name of the model of the human body - a visual aid for future doctors?

I found this visual material for obstetricians. Below is an excerpt from a help site about this visual aid.

PHANTOM OBSTETRIC, a visual teaching aid for teaching obstetrics, chap. arr. the course and mechanism of labor and obstetric operations. In its simplest form, F. a. consists of a bony female pelvis and a skeletonized head of a full-term fetus. Usually, however, under F. a. imply a pelvis built into something resembling the lower half of a woman’s torso with the upper halves of the thighs, and a “doll” depicting a full-term fetus. F. a. these are prepared from a wide variety of materials, from wood to a specially processed corpse; the same goes for “dolls”. For the first time he began to use F. a. for teaching at the end of the 17th century. Swedish obstetrician Horn, describing it in his textbook. This same textbook was the first educational book on obstetrics in Russian (“Midwife”, M., 1764).

Therefore, it is obvious that the correct answer to the question is in last place in the list of answer options, this is a phantom.

• ghost
• zombie
• phantom

Traditionally, on Saturdays, we publish for you the answers to the quiz in the “Question - Answer” format. We have a variety of questions, both simple and quite complex. The quiz is very interesting and quite popular, we are simply helping you test your knowledge and make sure that you have chosen the correct answer out of the four proposed. And we have another question in the quiz - What is the name of the model of the human body - a visual aid for future doctors?

• ghost
• zombie
• phantom

The correct answer is D. PHANTOM

Ghost, spirit, zombies, vampires, mutants - these are all manifestations of fantasy, heroes of mystical thrillers.

Medical students are now studying anatomy in pictures, morgue, in classes on physiology, histology, anatomy, and diseases, diagnosis and first aid medical care and other manuals on mannequins and simulators. Students learn to deliver a baby, provide cardiopulmonary resuscitation, give injections, vascular catheterization, intubation, tracheostomy, puncture of various cavities: pleura, joints, spinal puncture. The same phantoms are available in dentists, traumatologists and other specialties.