Human skeleton layout diagram. Human bone
Lesson topic
Human skeleton
Lesson Objectives
Continue to form schoolchildren’s ideas about the structure of the human skeleton;
To consolidate students’ knowledge about the human musculoskeletal system;
Lesson Objectives
Continue to deepen students’ knowledge on the topic “ Musculoskeletal system»;
Focus children's attention on the unique structure of the human skeleton;
Consolidate acquired knowledge by practical application using reference materials and working with diagrams and tables;
Promote the formation of reflexive qualities (self-analysis, self-correction);
Develop students' communication skills;
Facilitate the creation of a psychologically comfortable environment in anatomy lessons;
Cultivate schoolchildren's interest in biology lessons.
Basic terms
From a biological point of view, a skeleton is biological system, which is a reliable support for the human body.
The human skeleton in translation sounds like dried up, and denotes a collection of hard bones in the body, which serve not only as a support for the body, but also for its individual parts, and also plays the role of the body’s protective functions from various types of damage.
Bones are the components of the skeleton and its main elements.
Human skeleton
Even without studying anatomy, each of you knows that the human skeleton is made up of different bones, but what is its need... We will try to figure this out together.
The skeleton is needed to support the body, protect the internal organs and maintain the shape of the body. In addition to all of the above, strong muscles are attached to the skeleton.
Firstly, thanks to the skeleton, a strong base is formed in which vulnerable parts of the body are located. It plays the role of a frame that is capable of fixing different parts of the body in a certain position. The bones of the chest act as protectors of the lungs and heart, and they have the ability to contract and expand as we breathe.
Secondly, the skeleton allows living beings to move. After all, nature designed it in such a way that the skeleton consists of different bones, each of which has its own specific shape and performs a specific role in the human body. The mobility and flexibility of the skeleton in our body is provided by joints, cartilage and ligaments.
The number of bones in the human skeleton can be debated for a very long time, since different people it is not the same. Basically, most adults have more than 200 bones in their body. But it should be taken into account that there are people who have an extra pair of ribs, others also have deviations in the number of vertebrae, and the skeleton of a newborn child has more than 350 types of bones. In addition, with age, some bones have the ability to grow together, and their number decreases. Therefore, it makes no sense to say about a specific number of human bones, since it is not possible to make an accurate count.
Exercise:
1. Can human bones grow throughout life?
2. Why do bones sometimes lose their strength?
3. What needs to be done to prevent bones from losing their elasticity?
Skeletal organization
The human skeleton, like all vertebrates, is divided into the axial and accessory skeleton. The first includes all the bones that are located in the middle and create the skeleton of the body. These include all the bones of the head, neck, spine and ribs with the sternum. And the accessory or peripheral skeleton includes the bones of the scapula, clavicle, as well as the bones of the upper and lower limbs.
Axial skeleton
Now let's take a closer look at the human axial skeleton.
Scull
The components of the skull are the bony base of the head, which protects the human brain and its organs of vision, hearing and smell. The skull is divided into the brain and facial sections and consists of flat and fixed bones, with the exception of the bones of the lower jaw.
To see what bones the brain and facial sections are made of, carefully look at the picture above.
Now look at the connection of the skull bones:
Exercise:
1. Name the bones that form the brain section?
2. Which of the bones of the skull skeleton are unpaired and which are paired bones?
3. Name the largest bones that are located in the facial region.
4. Name all the bones that belong to the axial skeleton.
5. Which bone of the skull is immobile?
Skeleton of the torso
The human skeleton consists of the rib cage and the spinal column. Rib cage is bone base the chest, behind which the internal organs are hidden, and it consists of the sternum, twelve thoracic vertebrae and ribs.
The ribs of the human skeleton look like flat curved arcs, the rear ends of which are connected to thoracic vertebrae, and the anterior ones are connected to the sternum with the help of cartilage. Such attachment of the ribs to the skeleton creates conditions for the mobility of the chest when a person breathes.
The spinal column is the main axis of the body, which is designed to support the human skeleton and is the main axis of the body. Inside the spine is the spinal cord.
The spinal column consists of 33–34 vertebrae, which is about forty percent of the length of the human body.
Four curves act as shock absorbers for the spine, protecting internal organs and the brain, and softening shocks during walking, running and jumping.
peripheral skeleton
The accessory skeleton, or peripheral skeleton as it is also called, consists of the skeleton of the limbs and is divided into the skeleton of the lower and upper limbs. TO upper section includes the shoulder girdle and limbs, and the lower one includes the pelvic girdle with its limbs.
Since the free limbs are securely attached to the bones of the belt and have good mobility, they are able to withstand considerable loads.
Naturally, the upper and lower limbs have different functions. The upper ones provide a person with the ability to perform various movements and operations, and the lower ones are needed for movement and support.
Upper limb belt
The upper belt consists of the shoulder blades and collarbones. And the skeleton of the upper limbs is divided into the bones of the shoulder, forearm and hand.
Lower limb belt
The pelvic girdle consists of three rigidly interconnected bones. In each such bone there is a spherical cavity into which the head of the lower limb bone enters. The motionlessly connected bones of the lower extremity girdle, fused with the sacrum, provide the human body with reliable protection internal organs and allow to withstand huge physical exercise.
Skeleton of the lower extremities
If we look at the skeleton of the lower extremities, we can see that it consists of the femur, bones of the lower leg and foot. The femur and tibia have an anterior joint in the form kneecap which provides mobility to the knee joint.
Homework
Look carefully at the drawing of a human skeleton and sign its digital symbols:
Give answers to the questions posed:
1. Name all the departments that make up the human skeleton.
2. Name the number of vertebrae in each of the sections of the spine.
3. What parts does the spine consist of?
4. What importance do the curves of the spine play for the human body?
The human skeleton is a movable support of the body to which movable muscles are attached. Without skeletal bones, we would look like shapeless bags.
There are only 206 bones in the human body. The bones of the limbs, spine and pelvis are the support of the body. The bones of the skull, chest and pelvis protect internal organs from damage. The bones are smooth and hard. But that's just outside. Inside they have a tubular structure and are filled with bone marrow.
Bones can break. Children have more plastic substance in their bones, and their fractures are rare. Old people have more in their bones mineral salts, their fractures occur more often, and their bones heal much more slowly than in children.
The skeleton, together with the muscles attached to it, participates in body movements. Many bones of the skeleton are movably connected through joints and ligaments. Thanks to the flexible joints of the bones, you can run and jump. Cartilage covers the surfaces of articulating bones at the joints, and in some places - in the ears, nose, between the sternum and ribs - it is part of the skeleton.
The spine consists of 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 fused sacral vertebrae and 3-4 coccygeal vertebrae. There are 32-33 vertebrae in the spine, and they are the most delicate in the entire body. Connected by ligaments and muscles that attach to bone processes vertebrae and separated intervertebral discs. The human spine has four curves that take some of the load off the vertebrae and allow us to stand upright and walk on two legs, and not on four, as almost all animals do. The curves also soften the shocks that occur when running.
The skull consists of 22 bones that are connected to each other and protect the brain from damage. All bones of the skull, with the exception of the lower jaw, are connected to each other using ossified sutures formed by dense tissue. The lower jaw is movable, allowing us to open and close our mouth. There are also 3 pairs of auditory ossicles in the skull.
The lower limb consists of the thigh, lower leg and foot. The joints that connect the bones of the lower limbs allow us to run and jump.
The skeleton of the upper limbs consists of the shoulder girdle and the skeleton of the arms. The shoulder girdle is the shoulder blades on the back side and the collarbone on the front, one end of which is connected to the sternum - the bone that makes up the central part chest. The arm skeleton includes the humerus, forearm bones, and arm bones.
There is only one bone (hyoid), which is not connected to the general skeleton.
The crown is the place on the head where the three main bones of the skull meet: two parietal and one frontal. If a book is placed on the head of a person standing upright, the book will lie on the crown of the head. In young children, connective tissue in this area for a long time does not ossify and remains soft. Ossification ends in the second year of life.
To avoid curvature of the spine, it is necessary to constantly monitor your posture and avoid incorrect positions body or uncomfortable positions, for example, while doing homework or sleeping.
Children are interested in how the world works and everything in it. Their curiosity makes no exception for humans. They are interested in how a person works, how he sees and hears, runs and jumps. Modern children learn about the human skeleton, which cannot be seen with the naked eye like skin or eyes, from cartoons and comics. This makes the skeleton even more interesting in the eyes of a child.
But you won’t see a human skeleton with the names of bones and muscles in cartoons and comics, and it won’t hurt children to memorize them little by little.
Knowledge of how complex and fascinating it is human body, will awaken in the child an interest in biology and medicine, and will encourage a more conscious approach to their health and the health of others. Finally, this knowledge will be useful to him at school, where he is already primary school become familiar with the human structure.
The skeleton and muscles are the framework that determines the shape of a person, protects his internal organs and allows him to move. If it were not for the skeleton, then the person would be like a shapeless jellyfish. Muscles are attached to the skeleton and enable any of our movements - from fluttering eyelashes to lifting weights.
Bones are made of organic and non-organic organic matter, the first of which provide them with flexibility, and the second with strength. Thanks to this, the bones are unusually elastic and strong. Their complex structure adds strength and flexibility at the same time. Any bone consists of several layers.
- The outer layer is made up of strong bone tissue.
- The next connective layer covers the outside of the bone.
- Loose connective tissue that contains blood vessels.
- At the ends there is cartilage tissue, due to which bone growth occurs.
- Another layer - nerve endings, through which signals are transmitted from the brain and back.
Contained inside a bone tube Bone marrow, which also comes in two types. Red is involved in hematopoiesis and bone formation. It is full of blood vessels and nerves. Yellow is responsible for the growth and strength of bones. We see that the skeleton, among other things, contributes to the renewal of blood. This is where they are born blood cells. If, due to illness, it ceases to perform this task, the organism dies.
In the organization of the skeleton, several groups of bones are distinguished. One of them is the main supporting structure of our body, which includes the spine, bones of the head and neck, chest and ribs. Together they form the axial skeleton. The second part is called the accessory skeleton and it includes the bones that form our arms and legs, and the groups of bones that provide their connection with the axial skeleton.
Skeletal structure
The bones of the head include the skull and bones of the middle ear. The skull houses and protects the brain. It consists of two sections: the brain and the facial. The first of which includes eight dice. There are fifteen of them in the front section.
Torso bones
This part of the skeleton includes the chest and spine, starting from the neck. We combine them because they are closely connected both literally (the chest is attached to the spine), and by location, and by the tasks they solve. These are some of the most big bones person. Their function is to provide protection to the heart, lungs, etc. Among them are spinal column and chest.
Spinal column
The human spine is the main support of the entire body, its main axis. It is he who ensures our upright posture. Thanks to the spinal cord, communication is provided between the upper and lower parts bodies. It contains five sections, consisting of 32-34 vertebrae. They are called according to their location - cervical, thoracic, lumbar, sacral and coccygeal.
Rib cage
The chest really looks like a cage, where 12 pairs of ribs play the role of a lattice behind which the heart, lungs, vital important organs. It ends with a flat, wide bone called the sternum. In total, the rib cage includes 37 bones.
Bones of the upper limb
This is what scientists and doctors call our hands. I don’t think it’s necessary to explain how much it means to a person to be able to do both lifting weights and cross-stitching with them. But think about how different problems they are designed to solve. This explains why they are quite complex structure. To the bones upper limb(VK) include the VK belt and the free part of the VK.
The belt includes the scapula and clavicle, connected by a ball joint to humerus. This is where the muscles are attached. In the free part of the upper limb there are three sections - the shoulder (humerus), forearm (radius and ulna) and brush. The most bones in this area of the arm are twenty-seven; they are noticeably smaller than the bones of the forearm and differ from them in shape.
Pelvic girdle
This belt provides connection between the spine and lower extremities, and also accommodates and protects the organs of the digestive, urinary and reproductive systems. The pelvis consists of three fused bones.
Bones of the lower limb
The skeleton of the leg resembles the structure of the arm. They are fundamentally designed the same, differing in size and some other details. Since it is the legs that bear the main weight of our body when moving, they are more powerful and stronger than the bones of the arm.
What are the shapes of bones
Depending on their functions in the human body, bones differ in shape. There are four types of bone shapes:
- Wide or flat (for example, near the skull);
- Long or tubular (mainly in the limbs);
- Short, such as the bones of the wrist;
- Asymmetrical, having a composite shape. These are the pelvic bones, vertebrae, etc.
Muscles of the head and face
Previously, only specialists could know the structure of a person, his skeleton and the list of muscles. Today, anyone who is interested in this topic can find a detailed anatomical atlas on the Internet, where detailed description movements of our body and all its parts that provide this. The most important role muscles and organs consisting of special elastic tissue that can
contract under influence nerve impulses. There are more than 640 different muscles in the human body. Among them are different kinds according to different settings:
- By the functions they provide;
- In the direction of the fibers of which they are composed;
- According to the form;
- In relation to the joints.
It’s not so easy to understand all this, so let’s look at the muscles depending on where they are located on our body.
When we talk about movement, we first of all imagine how our arms and legs work. Meanwhile, the muscles of the head and face also work hard, providing breathing, facial expressions, speech, and our nutrition. The strongest muscles in our body are the chewing muscles.
The muscles of facial expression and the muscles of the eye, unlike all others, are not attached to the bones. This allows them to be especially sensitive and guarantee the implementation of even micro movements. Thanks to this, we can convey both joy and sadness, the slightest change in emotions.
Neck muscles
This group of muscles allows us to turn around, bow, swallow something and speak, even breathe.
Muscles of the trunk
Muscles are attached to bones by tendons and perform various tasks. – provide mobility and the ability to maintain balance, fix joints. According to their functions and modes of action, there are those that contract synchronously during work or synergists, and muscles that perform opposite actions (antagonists). Most often, actions occur due to the fact that some muscles contract and other muscles relax at the same time.
The muscles of the body include the superficial and deep muscles of the back and chest, oblique, rectus and other abdominal muscles.
Pelvic muscles
These muscles begin on the bones of the pelvis and spine, are attached to the upper edge of the thigh and surround hip joint. Among them, two groups are distinguished: internal and external.
Muscles of the upper limbs
Among this group of muscles, the same parts are distinguished as in the bones of the hand:
- Muscles of the VK belt;
- Shoulder;
- The forearms provide flexion and extension of the forearm, hand and each finger.
Muscles of the lower extremities
Thanks to these muscles, a person walks and runs, swims or jumps. In order to provide such different actions no single different muscle group is required. These include the muscles of the thigh, leg and foot. This is a rather complex system, including muscles that are different in shape, direction of fibers, in relation to joints, etc., mutually complementing each other.
Muscle anatomy Muscle physiology How muscles work
Skeleton(from the Greek skeleton - dried) of a person is a collection of bones connected to each other in a certain way. The adult human skeleton consists of approximately 205 bones. The skeleton (Fig. 12) has three sections: the skeleton of the body, the skeleton of the skull and the skeleton of the limbs (Table 2).
Rice. 12. Human skeleton (front view):
1 – brain skull, 2 - facial skull, 3 - bones of the upper limb girdle, 4 - humerus, 5 - bones of the forearm, 6 - bones of the hand, 7 - chest 8 - spinal column, 9 - bones of the lower limb girdle, 10 - femur, 11 - bones shin, 12 – foot bones
| Bones of body parts | Names of bones and their number |
| Torso bones | Vertebrae – 31 – 33 cervical – 7 thoracic – 12 lumbar – 5 sacrum (5 fused sacral vertebrae) coccyx (3 – 5 coccygeal vertebrae) Ribs – 12 pairs Sternum |
| Skull bones | 23 bones, including unpaired ones - frontal, occipital, sphenoid, lower jaw, hyoid bone and paired bones - parietal, temporal, zygomatic, etc. |
| Bones of the upper limb | 32 bones in one upper limb: clavicle, scapula, humerus radius carpal bones – 8 metacarpal bones – 5 phalanges of fingers – 14 |
| Bones of the lower limb | 31 bones in one lower limb: pelvic bone, femur, patella tibia fibula tarsal bone – 7 metatarsals– 5 phalanges of fingers – 14 |
The skeleton of the body consists of the vertebrae that form the spine and the bones of the chest. Each segment of the human body skeleton is formed by a vertebra, and in the thoracic region also by a pair of ribs and a section of the sternum.
The skeleton of the head, the skull, protects the brain, sensory organs and serves as a support for the initial sections of the digestive and respiratory organs. The skull is conventionally divided into two sections - the brain and the facial.
The skeleton of the upper and lower extremities is divided into the skeleton of the free limb and the skeleton of the belt. The skeleton of the upper limb girdle (shoulder girdle) consists of two paired bones - the scapula and the clavicle, and the skeleton of the free upper limb - of three sections: the humerus, the bones of the forearm and the bones of the hand.
The skeleton of the lower limb girdle (pelvic girdle) consists of a steam room pelvic bone, and the skeleton of the free lower limb is divided into three sections: the femur, the bones of the leg and the bones of the foot. Each bone is an independent organ that performs a specific function.
The bones of the skeleton differ in shape and structure. Distinguish tubular, spongy, flat, mixed And air bones(Fig. 13).
Rice. 13. Types of bones:
1 – long (tubular) bone, 2 – flat bone, 3 – spongy (short) bones, 4 – mixed bone
Tubular bones are divided into long (humerus, femur, bones of the forearm and tibia) and short (tarsal and metatarsal bones, phalanges of the fingers). Except for the bones articular surfaces, covered with a connective tissue membrane - periosteum, which performs bone-forming and protective functions. The periosteum is firmly fused to the bone with the help of connective tissue fibers that penetrate deep into the bone. The outer layer of the periosteum is coarsely fibrous, consisting of complexly intertwined fibers and connective tissue cells. This layer contains many blood vessels and lymphatic vessels, nerve fibers that provide vital activity to the bone. The inner layer of the periosteum is thin and contains cells from which osteoblasts are formed - young bone cells. Due to the bone-forming function of the periosteum, the bone grows in thickness and heals during fractures.
Inside the bones there are medullary cavity(in tubular bones) and cells of spongy substance, which contains bone marrow. In a newborn and in childhood, the bone marrow cavities are filled with red bone marrow, which performs blood-forming and protective functions. Red bone marrow stem cells form blood cells (erythrocytes, leukocytes) and immune system cells (lymphocytes). In an adult, red bone marrow is stored only in the cells of spongy bone. Other bone cavities contain fatty yellow bone marrow that has lost its function.
On the side of the medullary cavity and cells, the bone is covered with a thin connective tissue plate - endostome, also producing bone tissue.
The bones of the skeleton and the skeleton in the whole body perform supporting, motor and protective functions. Bones are also a depot for minerals - phosphorus, calcium, iron, copper and other trace elements.
Bone Strength is ensured by the presence of organic and inorganic substances in them, as well as the structure of bone tissue. In terms of hardness and elasticity, bones can be compared with bronze and cast iron. The compact and spongy substance of bones is built from bone tissue. Compact (dense) bone substance forms the outer layer of each bone. spongy substance, formed by bone crossbars (beams), is located under the compact substance. U tubular bones in the area of their body (diaphysis), the compact bone substance is thick (up to 1 cm). At the ends of tubular bones and flat bones and other bones, this layer is thin. The compact bone substance is penetrated by a system of bone canals in which blood vessels and nerve fibers(Fig. 14).
Rice. 14. Scheme of the structure of the tubular bone:
1 - periosteum, 2 - compact bone substance, 3 - layer of outer surrounding plates, 4 - osteons, 5 - layer of internal surrounding plates, 6 - medullary cavity, 7 - bone crossbars of cancellous bone substance.
Each bone canal (osteon canal) is surrounded by concentric plates in the form of 4 to 20 thin tubes inserted into one another. The system of such tubes together with the tubule is called osteona, or Haversian system(Fig. 15). The spaces between osteons are occupied by intermediate, or intercalary, plates, which, during bone restructuring due to changing physical load, serve as material for the formation of new osteons. The surface layer of compact bone substance is represented by the outer surrounding plates, which are a product of the bone-forming function of the periosteum.
Rice. 15. Structure of osteon in a section: 1 – osteon plates, 2 – bone cells (osteocytes), 3 – central canal (osteon canal)
The inner layer of bone, bordering the medullary cavity, is formed by internal surrounding plates and covered with fibrous connective tissue - endosteum.
Spongy bone substance located under the compact, is located at the ends of the tubular bones - the epiphyses, in the bodies of spongy, mixed bones, in flat and pneumatic bones. Spongy bone substance consists of bone crossbars intersecting with each other in different directions. Their distribution corresponds to the direction of the main lines of compression (pressure) and tension acting on the bone (Fig. 16).
Rice. 16. Scheme of the location of bone crossbars in the cancellous substance of bones (cutting of the upper end of the femur): 1 – compression (pressure) lines, 2 – tension lines
This arrangement of the bone crossbars at an angle to each other ensures uniform distribution of pressure and muscle force on the skeletal bones.
Bone is highly plastic. Depending on the load on the bones, the number of osteons increases or decreases, and their location in the compact substance changes. With constant muscle load, sports, physical labor the number of osteons and their sizes increase, the layer of compact bone substance in tubular and other bones thickens, and the bone marrow cavities narrow. The bone crossbars (beams) of the spongy substance also thicken and acquire a more complex structure (branch). At the same time, the bones become thicker and stronger. With a decrease in physical (muscle) activity, a sedentary lifestyle, and prolonged bed rest during illness, the bones become thinner and weaker.
Organic and inorganic substances also provide bone strength. Organic substances give bones flexibility and elasticity.
Inorganic substances (calcium phosphate, calcium carbonate and other salts) give bones hardness. In living bone, organic substances account for about 60% of its mass, the rest belongs to inorganic compounds.
The influence of organic and inorganic substances on the strength properties of bones can be tested experimentally. Once the organic matter is removed by roasting the bone over a fire, it becomes brittle. Removing inorganic substances (salts) from the bone by keeping the bone in acid makes the bone soft and flexible. The combination of the hardness of inorganic compounds with the elasticity of organic compounds ensures the strength of bones.
Related information.
Everyone knows about the existence of bones in our body. Being a solid skeleton, the skeleton (from the Greek “skeleton” - “dried”, “dried”) performs in our body various functions, the main one is supporting: it holds all organs in a certain position, takes on the entire weight of the body. And together with muscles and connective tissue formations - cartilage, ligaments, tendons - it gives us the ability to move, creates structural form body, determines its size. In addition, bones, muscles and ligaments serve as a reliable shell for the internal organs and tissues hidden in the body. In Figure 1 you can view the human skeleton.
Rice. 1. Human skeleton.
The human skeleton consists of interconnected bones. Bone tissue V total mass body – 10–15 kg (for men a little more), i.e. makes up 1/5–1/7 of a person’s body weight. It is not possible to indicate the exact number of bones in the human body. First, it varies somewhat from person to person. Approximately 20% of people have abnormalities in the number of vertebrae. One person in every 20 has an extra rib, and it is about three times more common in men than women (contrary to the biblical legend of Eve's creation from Adam's rib). Secondly, the number of bones changes with age: over time, some bones grow together, forming dense sutures. Therefore, modern scientists are careful to point out that a person has “several more than 200 bones,” and in a child’s body there are about 300 of them. Each bone has a certain shape, size and occupies a certain position in the skeleton. Some of the bones are connected to each other by movable joints, which are driven by the muscles attached to them.
Watch video 1.
Guys, watch the video."
The human skeleton is divided into: the axial skeleton and the peripheral skeleton. Figure 2.
Rice. 2. Diagram of the structure of the human skeleton
Axial skeleton. Skeleton of the head (skull)
Consists mainly of flat, immovably interconnected bones. The only movable bone of the skull is the lower jaw. The skull protects the brain and sensory organs from external damage, provides support for the facial muscles and the initial parts of the digestive and respiratory systems.
The skull is divided into a large cerebral and smaller facial (visceral) sections. Brain department form bones: unpaired - frontal, occipital, sphenoid, ethmoid and paired - parietal and temporal.
The largest bones facial section– paired zygomatic, maxillary, nasal, lacrimal and unpaired – lower jaw and hyoid bone located on the neck.
You can see the skeleton of the skull in Figure 3.
Rice. 3. Head skeleton
Figure 4 shows the connection of the skull bones
Rice. 4. Connection of the skull bones
We will see a model of a human skull in video 3
Skeleton of the torso
The skeleton of the body consists of the spine and thoracic cells. Figures 5 and 6 respectively.
The spine connects the parts of the body, performs protective function For spinal cord and support for the head, arms and torso. The length of the spine is 40% of the length of the human body. The spine is formed by 33–34 vertebrae. It distinguishes the following sections: cervical (7 vertebrae), thoracic (12), lumbar (5), sacral (5) and coccygeal (4-5). In an adult, the sacral and coccygeal vertebrae fuse into the sacrum and coccyx. In humans, the coccygeal vertebrae are the least developed. They correspond to the caudal vertebrae of the animal spine.
Rice. 5. Spine
The spine has 4 bends that act as shock absorbers: thanks to them, shocks when walking, running, jumping are softened, which is very important for protecting internal organs and especially the brain from concussions.
The spine is formed by vertebrae. A typical vertebra consists of a body from which an arch extends posteriorly. Processes extend from the arch. Between the posterior surface of the vertebral body and the arch is the vertebral foramen. Overlapping each other, the vertebral foramina form spinal canal which contains the spinal cord.
Now guys try to complete the task yourself( Make a copy of the document first. Sign the document indicating your first and last name).
The structure of the cervical vertebrae
The structure of the cervical vertebrae
The rib cage is formed by 12 pairs of ribs, thoracic vertebrae and a flat breastbone– sternum The ribs are flat, curved bones. their posterior ends are movably connected to the thoracic vertebrae, and the anterior ends of the 10 upper ribs are connected to the sternum with the help of flexible cartilage. This ensures the mobility of the chest during breathing. The two lower pairs of ribs are shorter than the others and end freely. The rib cage protects the heart, lungs, liver, stomach and large vessels from damage.
Rice. 6. Chest
Upper limb belt
Formed by two shoulder blades and two clavicles. The skeleton of the upper limb (Figure 7) consists of three sections: the humerus, the bones of the forearm (radius and ulna) and the hand (3 sections - wrist, metacarpus, phalanges of the fingers). The humerus forms a movable connection with the scapula ( shoulder joint), allowing you to perform various movements.
Rice. 7. Skeleton of the upper limb
Lower limb belt
The girdle of the lower extremities (pelvic girdle) consists of three bones that are motionlessly connected to each other, fused with the sacrum, which allows them to withstand heavy physical loads and perform a protective function for internal organs. Each pelvic bone has a spherical socket into which the head of the bone of the free lower limb fits.
