General overview of the structure of the human body

Work 2.
1. Read § 1 “Human Sciences”, fill in the table.

2. Consider in the textbook a reproduction of Rembrandt’s “Anatomy Lesson of Dr. Tülp” picture (Fig. 1) and in the “Functions” column describe the work of the forearm muscles.
Structure.
The muscles are located on the palmar side of the forearm, have a tape-like shape. At one end they are attached to the bones of the forearm, the other to the bones of the fingers.
Functions.
Finger flexion.

Work 3.
Read the article “Body Structure. The place of man in nature ”(§ 2). Determine the ratio of body parts.

1. Measure and compare the length of the ear (6 cm) and nose (6 cm); the length of the forearm (22 cm) and feet (22 cm).
2. Measure the knee circumference (29 cm). Does the knee circumference really fit the neck circumference?
The circumference of the neck is equal to the circumference of the knee.
(Figures may be different for boys and girls!).

Work 4.
Consider the drawing “Internal Organs of a Person” on the first flyleaf of the textbook.
1. Locate the thoracic obstruction, organs of the thoracic and abdominal cavities. Write down the names of these bodies and put the numbers by filling out the table.

2. Fill in the blanks in the text.
The right lung has three lobes. The liver is located in the abdominal cavity right upper quadrant, stomach - in the abdominal cavity. The appendix is ​​in the right groin.

Work 5.
1. Insert the missing words.
In the cranial cavity are the cerebral hemispheres, the diencephalon, the midbrain, the cerebellum, the medulla, the bridge, and the cerebral vessels.
In the cavity of the spinal canal is the spinal cord.
In the chest cavity are the heart, blood vessels and nerves, lungs, respiratory tract.
In the abdominal cavity are the stomach, liver, spleen, intestines thick and thin, the pancreas, kidneys, blood vessels and nerves.

2. List the organs that begin in the chest cavity, and end in the abdominal cavity.
Esophagus, vessels and nerves.

3. What bones protect the abdominal organs?
The spine is at the back, the pelvic bones are at the bottom.

4. Take a deep breath and exhale and follow the movements of the abdominal wall. Could its wall move easily if it had a bone base?
Could not. The abdominal wall does not have a bone basis, but only the abdominal muscles. This ensures the normal breathing process: inhaling and exhaling, the work of the diaphragm and muscles chest.

5. Look at the table “Man in the system of the organic world” (A) and write down the biological signs that allow
feed the young milk: the presence of mammary glands in females, nasal and oral cavity  separated by a soft and hard palate, there is no gap between the teeth and cheeks;
maintain a constant body temperature: hair and subcutaneous fatty tissue;
maintain a high metabolism due to the peculiarities of the circulatory system: the heart is four-chamber, completely divided into 2 atria and 2 ventricles, one aorta extends from the heart;
respiratory system: lungs of the alveolar type, the air in them enters the tubes forming the bronchial tree.

6. Review the list of features that make it possible to assign a person to the primate order (Table 1, B), and write down the signs that allow
grab items: five-fingered limbs, the thumb is opposed to the rest, the finger and toes are provided with flat nails, not claws;

develop mental activity: complication of the anterior part of the brain, in particular, the large hemispheres.
7. Write down from the table. 1 (B) morphological features that allow higher primates and humans
increase the speed of movement: short body and long limbs;
go to erect: reduction of the caudal vertebrae, decrease in the number of thoracic and lumbar vertebrae, increase in the number of sacral vertebrae fused into the sacrum.

8. Write down from the table. 1 (D) morphological features that allowed a person to develop sound speech: brain department  the skull is larger than the facial one, the canines are equal to the incisors, there is a mental protrusion to which the muscles responsible for speech are attached, the maxillary part of the skull does not come forward;
to adapt to work: the sternum is articulated with the clavicle, the radius is movable relative to the ulna, the bones of the palm are movable, the thumb is contrasted with the rest;
to master an upright posture: the attachment of the skull to the spine almost coincides with the center of gravity of the head, the spine is S-shaped, the chest is flattened in the dorsal-ventral direction, the pelvic and lower limb bones are massive, the foot is vaulted, the toe is shortened, the thumb is not contrasted with the rest;
to lead a social life: the development of the cerebral cortex.

Skeleton

Bones interconnected by means of connective cartilage and bone tissue form a skeleton (Fig.6). The skeleton performs a number of functions that are important for the body. He is a propof the organism, soft tissues and organs are attached to various parts of the skeleton. With the help of the skeleton carried motion  person The skeleton also carries defense  most important organs and systems: the spine protects the spinal cord; the skull protects the brain; The chest protects the vital organs of the chest cavity - the heart, lungs; the pelvis protects the internal genitals and the bladder.

The skeleton performs a biological function, participating in the metabolism, especially in the mineral, as well as in the blood.

According to the structure and shape, the bones are divided into tubular (for example, brachial, femoral), spongy (vertebrae, small foot bones), flat (skull bones), volume bones (carpal bones and tarsal bones) and mixed. The bone consists of bone plates, which are combined in Bole major elements - the crossbar. The bone substance consists of them - compact or spongy, depending on the density of the crossbar.

The bone structure is closely connected with the function it performs. In those bones (or their parts), which perform primarily the function of support and movement, compact matter prevails. In the same areas of the bone, where, with a large volume, strength and lightness should be ensured, a spongy substance prevails.

The tubular bones are constructed of a spongy and compact substance, in shape resemble a tube, inside of which there is a bone marrow cavity (Fig.7). They function as levers of motion. The tubular bone distinguishes two ends, which are called the epiphyses (upper and lower), as well as the body, or diaphysis. Epiphyses consist mainly of spongy substance. There is a red bone marrow in its cells. The diaphysis is constructed from a compact substance, inside it there is a bone-marrow cavity. It is filled with yellow bone marrow.

Tubular bones include humerus, femur, forearm and tibia (long tubular bones), phalanges of fingers and toes (short tubular bones). Spongy bones - ribs, sternum, vertebrae, wrist, etc. - consist mainly of spongy substance covered with a thin compact layer.

Flat bones consist of two bony plates, between which is a spongy substance. Flat bones are scapula, pelvic bones, ribs, sternum. They have a small thickness, with a predominance of width and length. In volumetric bones, all sizes are about the same. These bones are the bones of the wrist and tarsus. Mixed bones include bones consisting of several parts, such as vertebrae.

All internal spaces of the bone — the medullary canal of the tubular bones, the bone cells of the cancellous and flat bones, as well as the articular thickenings of the tubular bones — are filled with bone marrow. In the cavity of the tubular bones is yellow bone marrow. The cells of the spongy bone substance contain red bone marrow. The bone marrow is the organ of blood formation and biological defense of the body. Outside the bone is covered with a thin connective tissue film - periosteum. The periosteum is rich in nerves and vessels. The cells of the periosteum, multiplying vigorously, ensure bone growth in thickness.

Skeleton head (skull)  (Fig. 8) consists of two sections - brain and facial skull.

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In the brain skull, there is a set, or roof, and basement. To the bones brain skull  include the frontal bone located in the anterior part of the skull, two parietal bones, occipital, sphenoid (main), two temporal and ethmoid bones. The cranial vault is formed by the frontal, occipital, and parietal bones, tightly interconnected. AT occipital bone  there is a hole through which the cranial cavity connects to the spinal canal. Here the spinal cord passes into the brain. Temporal bones form part of the side walls and base of the skull, and also contain organs of hearing and balance.

Fig. 8. Human skull

and - in front; b - from the side;

1 - frontal bone; 2 - parietal bones; 3 - temporal bones; 4 - occipital bone;

5 - cheekbones; 6- upper jaw; 7 - lower jaw

All the bones of the cerebral skull, except for the parietal, are involved in the formation of the base of the skull. Brain part  the skull serves as a receptacle of the brain and the sensory organs associated with it, protecting these structures from various kinds of damage.

The facial skull serves as a bone container for the sense organs (sight, smell), as well as the initial parts of the digestive (oral cavity) and respiratory (nasal cavity) systems. It is formed by paired bones - the upper jaw, the lower nasal sink, the palatal, zygomatic, nasal, lacrimal and unpaired bones - the vomer, the lower jaw and the hyoid bone. The upper and lower jaws are involved in the chewing apparatus; the upper jaw together with the palatal, lacrimal, and other bones are involved in the formation of the sockets, the nasal cavity and external nose, as well as the septum between the nasal cavity and the mouth (hard palate).

The vomer is part of the bony septum of the nose. Bottom turbinate (steam room) is attached by its upper edge to the side wall of the nasal cavity and separates the middle nasal passage from the bottom. Nasal bone  (also steam room) forms the back of the nose. A strong zygomatic bone connects the zygomatic processes of the frontal, temporal and maxillary bones and contributes to the strengthening of the bones of the facial skull. Upper jaw, sphenoid, ethmoid and frontal bones  contain large pneumatic sinuses, connecting with the nasal cavity. The sinus of the upper jaw is called Gaymorova.

The bones of the skull are interconnected by strong fixed joints - sutures. The only moving articulation is the paired temporomandibular joint connecting lower jaw  with the base of the skull.

Spine, its departments. The spine, or spinal column (Fig. 9) is the support of the body, protects the spinal cord in its channel, participates in the movements of the body and the skull. It consists of separate bone segments - vertebrae, interconnected by intervertebral cartilage, or disks. Each vertebra has a body, an arc, and processes — an unpaired spinous and paired transverse and articular. Between the body and the arc is a hole in the vertebra. When one vertebra is laid on one another, the vertebral foramina form a spinal canal in which the spinal cord is placed. The articular processes are used to form the intervertebral joints, in which movements of the vertebrae and the spine are performed. Ligaments and muscles are attached to the transverse and spinous processes. In different parts of the spine vertebrae have a different shape. In this regard, the following vertebrae are distinguished: cervical (7), thoracic (12), lumbar (5), sacral (5) and coccygeal (3-5). Sacral vertebrae are a single, fused bone (sacral bone, sacrum). The coccyx vertebrae are underdeveloped and also grow into a single bone. All vertebrae form a single vertebral column, held together by two longitudinal ligaments running in front and behind the spine. Intervertebral cartilage and ligaments give the spinal column flexibility and elasticity. Developed muscular system provides not only the mobility of the spine in a fairly wide scope, but also its strength.

The spine has bends, which in the chest and in the sacrum are directed by a bulge back (kyphosis), and in the cervical and lumbar - bulge forward (lordosis). Bends soften the shocks and tremors that occur when a person moves.

Rib cage formed by the ribs, which are connected to the back of the thoracic vertebrae, and in front - with chest boneor sternum. The ribs are narrow curved plates, mainly consisting of a spongy substance, and in the front part - of cartilage. There are a total of 12 pairs of ribs. The upper 7 ribs are connected directly with the sternum by the front ends and are called true; The 8.9 and 10th pairs of ribs join with their cartilages to the cartilage of the previous rib and are called false, and the 11th and 12th pairs of ribs with the front ends lie freely in the muscles of the abdominal wall and are called oscillating. On the upper surface of the I rib there is a small groove, in which the subclavian artery is located. At this point, it is possible her finger pressing in order to stop bleeding when injured.

The sternum consists of three parts: the upper arm, the middle body and the lower xiphoid process. On the sternum are rib cuts, which serve to connect with the cartilage of the ribs. Spongy substance of the sternum contains red bone marrow.

The chest contains vital organs - the heart, lungs, large vessels. Chest movements provide the process of human breathing. The ribs are located obliquely forward and downward from the spine. When you inhale, the front ends of them are raised and together with the sternum are removed from the spine, as a result of which the chest cell expands in anteroposterior and transverse dimensions. When exhaling, the ribs are lowered to their former position.

The spinal column, ribs and sternum make up the skeleton of the trunk. With the skeleton of the trunk connected shoulder girdleconsisting of two paired bones: the clavicle and scapula.

In various diseases and injuries for diagnostic purposes, it is often necessary to count the ribs and vertebrae, determine the location of the wound (surgical incision, etc.) with respect to exact anatomical landmarks. To do this, use the following rules.

The ribs are easily palpable from a person of normal build and nutrition. In this case, the first rib can be probed near its attachment to the sternum below the clavicle. The second rib is immediately and clearly felt immediately downwards from the middle of the clavicle. Therefore, when reading as a guide, they use the II edge, taking the clavicle (conventionally) as the I edge. On the border of the body of the sternum and the base of the xiphoid process, easily palpable on a person, the cartilaginous end of the VII rib connects to the sternum. In men, the nipple is usually located in the projection of 4 intercostal spaces. A scapula can serve as a fairly accurate guideline: its upper edge is located above the upper edge of the second rib, and the lower angle is above the upper edge of the VII rib.

Count vertebrae  conducted on the spinous processes. In the cervical spine is clearly defined protruding spinous process of the VII cervical vertebra. Immediately below it is determined spinous process I thoracic vertebra. The palpation of the vertebrae is facilitated by leaning forward. The horizontal line connecting the lower corners of the shoulder blades, usually passes over the spinous process of the VII thoracic vertebra. To count the lumbar vertebrae use the line connecting the upper points of the iliac crests. It takes place in the interval between the spinous processes of the IV and V lumbar vertebrae.

Skeleton upper limb  consists of two parts of the bones of the upper limb girdle and a free part (Fig.10).

Shoulder girdle  represented by the scapula, which is a flat bone, and the clavicle, the tubular bone. The scapula has an articular cavity to connect with humerus. The clavicle is connected to the sternum and scapula.

Fig. 10. Bones of the upper limb:

a - humerus: 1 - head of the shoulder; b - forearm bones: 1 - ulna; 2 - radius; in - bones of the hand: 1 - the lower end of the radial bone; 2 - the same, ulnar; 3, 4, 5, 6, 7, 8, 9, 10 - eight bones of the wrist; 11, 12 - the bones of the metacarpus; 13, 16 - phalanxes of 1 finger (13 - primary, 16 - nail); 14, 15, 17 phalanxes of the rest of the fingers (14 - the main ones; 15 - the middle ones; 17 - the nail ones)

The humerus is a typical long tubular bone. Its upper end has a spherical head, which connects with the articular cavity of the scapula, forming shoulder joint. Bottom end humerus  it is expanded and ends with two protrusions: the head of the condyle and the block that serve to connect with the bones of the forearm. The forearm is formed by the ulnar and radial bones, while the latter is located outwards (from the side of the thumb).

The ulna in the upper end has a bone protrusion - the ulnar process, limiting the back of the elbow joint.

To the lower ends of the bones of the forearm are adjacent the bones of the hand, which are divided into bones of the wrist, metacarpus and bones that make up the fingers, the so-called phalanges. The wrist consists of 8 volume spongy bones arranged in two rows. Metacarpus formed by five short tubular bones. The phalanges of the fingers are represented by short tubular bones. The first finger of the hand consists of two phalanges, the rest of the three. The bones of the hand are connected to each other and with the bones of the forearm by complex, combined joints, which ensure high mobility of the hand and the ability to perform complex and diverse movements.

The skeleton of the lower limb also consists of two sections: the belt and the free section.

Pelvic girdle  consists of paired pelvic bone. Both pelvic bones are connected in front of each other, forming pubic symphysis, and behind - with a sacrum. They form a bone ring - the pelvis, which connects the body with the lower limbs, and also protects the internal organs located in the pelvic cavity. From the outer surface pelvic bones  there are deep articular cavities involved in the formation of the hip joint. Skeleton of the free lower extremity  consists of the femur, patella, two bones of the leg and foot bones.

The femur is the largest and thickest of all long human bones. At the upper end, it has a circular articular head that connects with pelvic bone. The lower end of the bone is thickened, there are two condoms on it, which are involved in the formation knee joint.

The bones of the shin are tibial and fibula bones. The tibia is located on the inside, and the fibula is on the outside (on the side of the little finger). The upper end of the tibia has two condyle to connect with similar formations of the femur. At the lower end of both bones of the lower leg are the outer and inner ankles.

The foot consists of tarsus, metatarsus and phalanges of the fingers. Tarsus consists of seven bones, arranged in two rows. The largest of them is the calcaneus, which performs the main support function of the foot. Metatarsus consists of five short tubular bones resembling metacarpal bones. The bones of the toes of the foot — phalanx — are much smaller than the phalanges of the fingers. The first finger also consists of two phalanxes, the rest of them are three. The foot is an arcuate structure, convex upwards. This structure of the foot due to the presence of two types of bends - arches of the foot. Bends oriented along the foot, called the longitudinal arches, and passing across - transverse. The arched structure of the foot allows you to evenly distribute the load of body weight on the muscles of the leg and foot, to soften the tremors during walking, running and jumping.

Sometimes flattening of the arch of the foot may be observed. flat feet. This is a painful phenomenon in which a person experiences fatigue and pain in the muscles of the leg when walking. Flatfoot is easily installed based on the study of the footprint.

On external examination, it is easy to detect the main bone protrusions of the upper and lower extremities of a person, which serve as important anatomical landmarks. Well accessible and clearly defined when palpating the outer and inner nadminiki humerus, located in the lower part of the shoulder. At the same time, the inner namyster is stronger than the outer one. Between them, the ulnar process of the ulna is determined from behind.

In the area of pelvic girdle  palpation clearly defines the iliac crest, the ischial tubercle, and the greater twist of the femur. In the lower part of the thigh, in the area of ​​the knee joint, the femoral condyles and the patella are palpable. The latter is easily shifted with a relaxed limb. Throughout the tibia, the front surface of the tibia is palpable, and in its lower part - the inner ankle. Outside the ankle of the fibular bone is determined in the area of ​​the ankle joint. The external ankle is already internal and is located 1.5-2 cm below it.

The human spine, in contrast to animals, plays a huge role in the support function. In other mammals that walk on four limbs, this large and complex complex of joints is only a link for the paws. The human body, acquiring the skill of an upright position of the body, began to need an analogue of the forelimbs. In order not to lose stability, the spinal column became much larger, and also acquired physiological curves.

But due to such evolutionary changes, a person is faced with diseases of the spine, which arise from prolonged axial loads. To avoid them, nature has “equipped” the spinal column with a multitude of ligaments and muscles. Therefore, the soft tissues of the back serve not only as a support, but also as a protection for vertebral bones. They soften all the shocks and blows that inevitably form during movements.

This complex of various structures stretched from head to toe, forming the entire back of a person along with soft tissues. Such an extended location provided protection to many internal organs. From the back they are covered with a thick layer of bones, muscles and ligaments. Therefore, diseases of the spinal column occur so often - its role in the body is too responsible.

The structure of the spine

What parts emit in spinal column? For many people, it is represented by separate bones, which in the process of movement slide relative to each other. In part, this definition is correct - the joints between the vertebrae really do not communicate with each other. But in terms of anatomy, they are part of a system of complex compounds that cannot work separately. Therefore, the normal functioning of the spine is carried out only by the joint work of all vertebrae.

This anatomical formation consists of several departments that have characteristic features. Their main difference is the change in the shape and size of the vertebrae:

1. The cervical region is formed by small bones that have good mobility. The absence of large processes allows them to make movements in any plane. This is due to the flexibility of the neck, which quickly turns the head in the right direction.
2. The thoracic region becomes (together with the sternum) the supporting point for the attachment of the ribs. Together with these bones, they form the chest, ensuring its stability and mobility.
3. The lumbar spine is formed by the largest vertebrae, as it assumes the weight of the body. But, like the neck, the bones do not have large processes, and are not fixed by other formations. Therefore, in the lower back, you can make various movements.
4. The sacrum is represented by several accrete vertebrae, so it looks like a solid bone. It serves as the main support for the back, and also forms the back wall of the pelvis.
5. The tailbone consists of several small bones - it was inherited by man from his ancestors, animals. It is part of the tail, which man did not need in the process of evolution.

The neural tube, which will then become part of the spine, is the first organ germ in a child growing in the womb.

The role of the spine in the body

This huge bone structure, willy-nilly, assumes the role of the skeleton base. She shares it with the bone pelvis, but, unlike him, she has to participate in all human movements. In addition to the support function, the spine has a number of various properties, without which the body would have a hard time:

• It interconnects the rest of the skeleton - the skull, chest, girdle of the upper and lower extremities. From such a peculiarity, it is not easy for him - he has to participate in any movement.
• Cartilaginous intervertebral discs and ligaments play the role of a shock absorber, softening any human movement. If they were not there, then at every step people would shake from head to toe.
• It provides a vertical position of the body - it may seem that when standing, the spine is at rest. But this is not so - in this position almost all the muscles of the back are strained.
• Physiological curves - lordosis and kyphosis - do not allow soft tissues to tire easily, as they evenly distribute the load between them.
• The spinal column is a place where many soft tissues adhere. Muscles, tendons, vessels, nerves - all this passes along or through it. And it is so arranged that it does not allow even minimal damage to them.

Due to the large length of the spine, it is in contact in each department with different organs, which makes such a complex structure of the back.

What protects the spine?

In addition to various organ systems, this complex joint contains its own formations that must be protected. For them in the bodies of the vertebrae there are many holes through which they freely pass. But the main formation that stretches across the entire pillar is the spinal canal containing the spinal cord:

1. This organ is protected from external influences by the vertebrae themselves, as well as by a two-layer sheath. They produce a soft and hard layer that perform opposite functions.
2. When moving, the spinal cord does not stretch, as it is located freely relative to the shells.
3. His whole tissue is located only at the level of the cervical and thoracic - in the lumbar region, it already consists of many small nerves.
4. Inside the soft shell circulates cerebrospinal fluidwhich protects the body from tremors. It also provides its nutrition and exchange products.
5. The vertebrae are interconnected by a whole capsule, which eliminates the contact of the spinal cord with other organs during movements.

This protection system is due to the role of the spinal cord - it ensures the operation of all parts of the body and internal organs  person

What protects the cervical?

The neck is not only a moving part of the body, but also contains all the paths connecting the head and torso. Therefore, the greatest number of structures is observed precisely in the cervical region, where the spine is surrounded by many vessels and nerves:

• The vertebrae contain in their canal a part of the spinal cord, which is responsible for the functioning of the vital organs - the heart and lungs.
• The vertebral arteries, which are the main source of nutrition for the brain (together with the carotid arteries), pass through their processes.
• Bones provide support for neck organs - respiratory tract, esophagus. Back wall  the pharynx is completely attached to the vertebrae. If it were not for such protection, the person could not breathe freely and swallow.
• The vertebrae provide the normal position of the vascular bundles that provide blood supply to the brain.
• In this section are located the nerve plexus, which ensures the functioning of the upper limbs.

Therefore, neck injuries are so dangerous - even a slight dislocation can damage important structures.

What protects the thoracic?

The thoracic vertebrae form the basis for the chest - a solid framework of ribs closes on them. This firm and flexible structure closes all organs located in the chest:

• Together with the pectoral muscles, respiratory movements are created that ensure the mobility of the lungs. Inhalation and exhalation are carried out due to alternate changes in the tone of these muscles.
• The heart is firmly hidden behind the bony structures, like a stone wall.
• A number of important vessels pass along the thoracic segment - the aorta, the inferior vena cava, the main lymphatic trunk. They are located on the side of the spine, and secured with soft tissues. Their damage is fatal to humans, so they are covered behind a layer of bones, muscles and ligaments.
• The tissue of the liver and spleen is easily affected and bleeds in the event of injury, so it is safely hidden from them behind the bone structures. Their envelope is connected to the vertebrae by a multitude of ligaments, which create their immobility.

The thoracic region is treated as one with the ribs and sternum, as it is firmly connected with the joints.

What protects the lumbosacral region?

This part of the back contains a powerful layer of muscles that support the human body in an upright position. It also provides protection to many organs and entities located in this segment:

• The kidneys are entirely dependent on the lumbar vertebrae - their soft tissues form a special “bed” for them. It is a pocket in which they are without the support of ligaments. A large thickness of the muscles keeps them warm, which is vital for them.
• Aorta and large veins run in the direction of the lower limbs along the entire loin. Large vertebrae protect them from damage from the back.
• The intestine is in an orderly position, as the folds attached to the anterior surface of the vertebrae are directed to its loops.
• The lumbar region and the sacrum serve as a receptacle in which powerful nerve plexuses are located. They form a multitude of nerves heading towards lower limbs. Here also the protection of the spinal cord is performed, since these fibers are its final divisions.

Together with such "responsibility" the loin should have sufficient mobility. Therefore, all the formations are located at a sufficient distance so that during the movements they would not be infringed.

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• Joint pains limit your movement and full life ...
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• But judging by the fact that you are reading these lines - they did not help you much ...

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