The structure of the child's skeleton. Anatomical features of children

A child is considered a newborn until he is one month old. This month is a kind of transition period from the intrauterine existence of the fetus to life in the human world. The baby has not yet gotten rid of many innate reflexes, sees poorly, hardly blinks and is not at all adapted to new conditions. He exists only in close connection with his mother and is completely dependent on her. During this period, the child is characterized by many interesting features that he will lose as he grows up.

Cry

Newborns cry without tears. This is due to narrowing or, less commonly, blockage of the tear glands. Instead of the usual crying, the baby screams loudly, thereby expressing anxiety, pain, hunger or discomfort. Scientists have proven that when a baby cries, it copies the intonations and accent of its mother, which it overheard while still in the womb. This is also evidenced by the results of a scientific study in which 60 children with their parents were involved: 30 speaking French and the same number speaking German. It was found that French babies cry with a rising intonation, which is characteristic of the French language, and German babies cry with a descending intonation, which is characteristic of the German language.

Skeleton

The skeleton of a baby contains more than 300 bones, while the skeleton of an adult consists of only 206. However, this is quite simple to explain - some of the bones of a newborn grow together as they strengthen and grow.

Respiratory system

A baby, unlike adults, can breathe and swallow at the same time. In this way he is similar to animals. The baby uses this amazing ability for about 9 months, while the articulatory apparatus is formed and complicated and the larynx moves down.

Another amazing property characteristic of infant breathing is that children breathe several times more often than adults. For comparison: the respiratory rate of an adult is about 20 times per minute, a baby aged one year is 33 to 36 times, an infant is from 30 to 45 times per minute.

In addition, newborns cannot breathe through their mouths. They will learn this much-needed skill only the first time they experience nasal congestion: during a cold or allergy.

Eye shape and color

The size of children's eyes remains the same throughout their lives. This is why a baby’s eyes seem so huge and deep to us. But the nose and ears tend to grow throughout life. In addition, it is surprising that every child, with rare exceptions, is born with a gray or blue iris. This is due to a temporary lack of a pigment called melanin. Already in the process of growing up, the eye color acquires a constant shade, this happens around six months. ()

Swimming ability

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The fetus spends all its development before birth in an aquatic environment, so more than 90% of babies retain the swimming reflex. It is thanks to him that the baby is able to swim and dive, making floundering body movements. Your baby's body helps conserve oxygen for the lungs and heart by slowing blood flow to the toes and reducing the beating rate of the little heart by as much as 20%. If the reflex is not strengthened, it will be lost by 3–4 months. ()

Heartbeat

The baby's heart beats incredibly fast - with a frequency of up to 130 - 160 vibrations per minute. During crying, the frequency can reach 200 beats. For comparison, the heart rate of an adult is 60 – 80 per minute.

Visual features

Newborn vision is an understudied phenomenon. Only recently, scientists have refuted the theory that a baby sees the world around him as flat. In fact, three-dimensional images are available to him from birth.

Otherwise, science is adamant - the baby does not see very well, only 25 - 28 cm, which will be approximately equal to the distance from the mother's nipple to her eyes. The first couple of weeks after birth, the baby perceives the surrounding reality in black and white, and only by the third week after birth begins to gradually distinguish colors. Any baby prefers bright colors and large patterns; it’s easier to focus their eyes on them.

Another interesting fact is that babies blink much less often than adults: only 1–2 times per minute. So far, medicine has not been able to find the causes of this physiological feature.

Taste

The baby’s food preferences are formed during the 7–9 months of the mother’s pregnancy and are finally consolidated by the first year of the baby’s life. It has been proven that the baby enjoys more familiar smells and tastes that entered his body earlier - with breast milk or as part of the amniotic fluid. This physiological feature explains why breastfed newborns get used to complementary foods faster than those children who were fed artificial formula.

Meteor dependence

Blonde babies react more acutely to changing weather conditions than their brunette peers. Twins and twins, premature babies are characterized by increased sensitivity. This susceptibility increases even more after illness, stress and vaccinations.

This is exactly how the little man comes into our world. Don't be surprised or worried if it doesn't meet your expectations. In just a few weeks you will learn to understand your baby and communicate with him using the language of sight and gestures. The newborn adapts to the world around him: he will learn to cry, smile charmingly and happily walk when he sees you.

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The skeleton is a particularly important part of the complete, healthy functioning of the human body. Thanks to bones, the body is always in shape and in the desired position. Bones form the skeleton, which in turn also performs the protective function of internal organs and systems from external influences. All this applies to both adults and children from the womb.

Formation of the fetal skeleton

More than 70% of the bones consist of very strong bone tissue, which contains many minerals. The main ones include: magnesium, phosphorus and calcium. Other elements are also necessary for the full formation of the fetal skeleton: zinc, copper, aluminum and fluorine. The fetus receives these and other substances through the placenta from the mother’s body. Therefore, it is extremely important for pregnant women to eat well and eat well. Starting from the fifth week of pregnancy, the foundations of cartilage are laid in the fetus - the future bones of the spine and shoulder girdle. The outlines of the pelvic girdle also appear. The fetus, which is already 9 weeks old, has formed fingers and jaw bones. Many people know that a newborn baby has more bones than an adult. This is due to the fact that in the future the cartilage will grow together to form one bone. The complete formation of the skeleton will occur at 24 years of age.

How many bones does a child have?

Many parents are convinced from their own experience that their child’s bones are more likely to bend than to be injured. Without taking into account, of course, serious damage. Very often, newborns fall out of bed or sofa, while “pah-pah” everything is fine. All this is because their skeleton is dominated by cartilage, which will then strengthen and become bone. So how many bones does a baby have? A newborn baby has 300 fragile bones in its small body. And only by the age of 24-25, 206 strong, durable bones will be formed from them.

This process occurs due to the intake of calcium and other necessary substances into the body.

Bone injuries in a child

How many bones are in the body of a small child - it’s clear, now about their injuries. Childhood injuries, to the great joy of parents, are quickly restored.

This is all due to the fact that in a child’s body there are cells responsible for the structure of bone tissue. And if it happens that the child is injured, these cells end up on the injured area. Thus, even a fracture in a child will heal much faster than in an adult. A child's injury will go away after 2-4 weeks, an adult's - 6-8. All young mothers and others need to know how many bones are in a child’s body. This will allow you to be more educated in this area and provide the necessary assistance to the child in case of injury.

Difference between bone of an elderly person and a child

We figured out how many bones are in a child’s skeleton. Now the question that worries many is: “What is the difference in the skeleton of an elderly person and a child?” Children's bones are much thinner than those of adults, including the elderly. Thanks to this, the child’s motor system is much more mobile and elastic. Around the age of 12-13, the child’s bones are almost completely similar to those of adults. However, cartilage is still found in some places. During adulthood and closer to old age, the relief of the cranial bones noticeably smoothes out.

Also, when teeth are lost, the weight of the skull decreases, which can provoke malocclusion and cause facial asymmetry.

The most pronounced changes in skeletal structure with age occur in the spine. After 40-50 years, this part of the skeleton becomes more compressed and slightly shorter than it was before. This is due to the fact that the intervertebral discs and vertebrae fit closer together. After 60 years, bone tissue begins to grow, and spine-like formations appear throughout the body.

So, the main differences between the skeleton of an elderly and a small person:

1. The main and first difference is, of course, quantity. How many bones do a small child and an elderly person have? Child - 300 dominoes, adult - 206.
2. The bone tissue of a child is richer in spongy substance than the bone of an elderly person.
3. Another important difference is mobility. The child's skeleton is more active and elastic, which cannot be said about the skeleton of older people.
4. With age, tissue changes, which leads to weakening of the skeletal bones. A noticeable decrease in calcium and fluorine in the body first makes itself felt.

In the maternity hospital, the pediatrician treats the baby very carefully, checking, among other indicators, whether there are any congenital pathologies in the development of his bones and joints.

Features of the structure of bone tissue of a newborn baby

A newborn's joints are very similar in structure to the joints of an adult, but the skeletal system is very different. Only about 50% of the components of bone tissue can be classified as ash substances. Everything else is mainly cartilaginous elements that allow the child to grow and will gradually decrease in volume. This process usually lasts up to 18 years and is completely completed only by 25 years.

Bone tissue in a newborn is contained only in tubular bones, while other elements of the skeleton include only small points of ossification, which increase as the baby grows.

This composition makes the child’s skeletal system very plastic, which means the newborn’s bones and joints are easily deformed. The baby's skeleton is so vulnerable that it can change even under prolonged exposure to gravity. That is why you should not allow the child to remain in the same position for a long time or carry him in your arms in a constant position. The newborn must be periodically turned over to the other side, transferred to the other hand, etc.

For the same reason, pediatricians do not advise putting the baby on his feet too early, even if he tries to do it himself. Such experiments can lead to deformation of individual bones and the entire skeleton of the child.

How does a child's skeleton grow?

The structure of the bone tissue of a newborn also has its differences. The bones of a newborn are a coarse fibrous bundle system in which a number of bone plates are randomly located. If the bones of an adult have significant cavities filled with yellow bone marrow, then in an infant such cavities are very small and contain mainly red bone marrow.

Thanks to the large amount of red bone marrow, the child's skeletal system receives an adequate supply of blood necessary for its growth. This process occurs intensively until approximately two years of age. After some decline, the growth process resumes with renewed vigor already in puberty.

The growth of bones in length is ensured by epiphyseal cartilage. Its peripheral edge remains active until the age of twenty-five, due to which the bones have the main opportunity to increase in length and the child becomes taller.

The periosteum is responsible for the thickening of bones and their growth in width. In a child, it is dense, thick and functionally more active. This feature of the periosteum is very favorable for the child, since even with fractures the periosteum often remains intact, and the bone protected by it heals faster and without dangerous consequences for the child’s musculoskeletal system.

The basis of the tissue of a newborn’s joints, as well as his bones, is cartilage tissue. The mobility of all elements that form the joints also differs. Since the newborn has not yet developed the joints, the amplitude of possible movements is still very small, but the likelihood of dislocations if handled carelessly is quite high. Such immaturity of the joints, as a rule, persists up to three and even up to five years, that is, until the tissue of the bones and joints has developed sufficiently and the child has fully mastered the science of controlling his body.

A newborn baby looks so fragile that a young mother is sometimes afraid to even just touch him. Sometimes such a reverent attitude towards the baby is completely justified. The bones and joints of a newborn baby continue to form and are very vulnerable, and when young parents understand this, this is not bad at all.
When a pediatrician examines a newborn in the maternity hospital, he treats him very carefully and carefully and, among other indicators, checks whether the baby has pathologies in the development of joints and bones.

Features of the structure of bone tissue of a newborn baby

The skeleton of a newborn consists of 50% cartilaginous elements, which ensure the baby’s ability to grow. With age, cartilage tissue gradually transforms into bone, and this process, as a rule, continues until the age of 18, and its complete completion should occur only by 23-25 ​​years.

The bone tissue of a newborn baby is contained exclusively in tubular bones; the remaining elements of his skeleton contain only tiny points of ossification, which will increase as he grows.

This structure of the baby’s skeletal system makes it hyperplastic, thanks to which he was able to pass through the mother’s birth canal. At the same time, the skeleton of a newborn is vulnerable to such an extent that it can become deformed even with prolonged exposure to gravitational forces. For this reason, experts recommend changing the baby’s position from time to time and not carrying him in the same position in your arms. Newborn babies must be periodically transferred to different hands and turned from side to side. It is not recommended to put the baby on his feet too early; wait until he is physically mature for this. This also applies to early placement of a child in pillows. These experiments usually lead to deformation of the baby's skeleton or individual bones.

How does a child's skeleton grow?

The bone tissue of a newborn baby is mainly a bundled coarse fibrous system, in the mass of which bone plates are randomly located in a small number. Unlike an adult, whose bones have cavities filled with yellow marrow, in infants these cavities are tiny and filled mainly with red bone marrow, through which the child’s skeleton is supplied with the substances necessary for further growth.

Epiphyseal cartilage ensures the growth of the child's bones in length. The peripheral edge of this cartilage remains active until almost twenty-five years of age, thanks to which human bones are able to grow in length and people become taller. But the periosteum is responsible for the growth of bones in width and their thickening. In babies it is thick, dense and has great functional activity.

For a child, this feature of the periosteum has very favorable aspects, even if, God forbid, the baby has a fracture, this tissue remains undamaged, and the bone protected by it grows together very quickly and without pathological consequences for the child’s musculoskeletal system.

Articles on the topic

Victoria Nikitina 20.06 15:04

I would rather call the bones and joints of a newborn not fragile, but soft, plastic and even flexible. It is especially important to monitor the correct formation of the hip joints. Therefore, placing the little one on his tummy, holding him by the shins, try to bend his legs at the knees and spread them apart. His pose should resemble that of a frog. Your thighs should be almost parallel to the surface of the table. And the butt should go down, and not rise up, like a chicken’s. Symmetrically located dimples should be visible on the lower back. If you cannot easily perform this exercise, then you should immediately consult with an orthopedist, take an x-ray of the hip joints and, possibly, put on stirrups.

Bone is a part of the human skeleton, consisting of several tissues. The most important of these is bone marrow. Each bone contains inorganic and organic substances. In the young skeleton, the former predominate, so the bone cover is more flexible and soft. In old people, bones, having lost a significant proportion of minerals, become fragile and break easily.

The number of bones in a person’s skeleton depends on his individual characteristics and may vary.

This occurs due to the fusion of several bones into a single whole, the absence of some small ones, or the presence of additional ones.

Skeletal functions

Serves as a support for the human body, determining its shape. Muscles are attached to it, which contract and provide mobility. Today, scientists know that bones are living formations that are constantly renewed, rebuilt and have blood vessels and a brain. From this understanding it follows that the functional significance of the skeleton is much broader than previously thought, namely:

In the body of an adult, mature human there are 206 bones. Some have a little less, some have a little more, but this amount can be considered the norm. 33-34 of them are paired. Skeletal bones are formed from two types of tissues: cartilage and bone. In addition to the cellular structure, intercellular substance is isolated.

The ratio of the skeletal mass of an adult to the total body mass is about 20%, however, with age, the figure gradually decreases.

In a newborn baby, the number of bones is determined in different ways. Some doctors believe that there are 300 of them, others - from 270 to 350. Babies' bones are very small, and it is important to determine at what size to count them. And that's the whole question. Newborns have different weights, and a premature baby may have bones smaller than the minimum size.

For several weeks, the embryo of a child has a rudimentary tail, which consists of individual bones. They later grow together and the coccyx is formed.

The baby's bones are soft and flexible; otherwise he could not have been born. During the prenatal period, the cartilaginous skeleton of the fetus gradually becomes bone. This process continues after birth for several years.

The child's skull bones are not fused. Between them there are fontanelles, which consist of connective tissue. They are overgrown with bone tissue by about two years. The vertebrae of the sacrum completely fuse into a single bone only by the age of 25.

Conventionally, the skeleton can be divided into four parts: the torso, the head, the girdle of the lower and upper extremities. Let's look at each department in detail.

Scull

The human skull has 25 bones: 17 facial bones and 8 brain bones. Facials include:

Brain:

• parietal – 2;
• frontal;
• wedge-shaped;
• occipital;
• temporal – 2;
• lattice.

Lower and upper limbs

The human upper limbs consist of the following bones:

The structure of the lower extremities, as well as the upper ones, are divided into:

1. Waist section:

• pelvic;
• ileal;
• ischial;
• pubic.

2. Free part:

• patella and femur;
• fibula and tibia.

3. Tarsus:

• foot;
• ram;
• heel;
• medial wedge-shaped;
• scaphoid;
• intermediate wedge-shaped;
• lateral;
• cuboid.

4. Metatarsus.

5. Fingers:

• middle phalanges;
• proximal;
• distal.

Torso

The human torso consists of the chest and spine. In its turn, The spine has five sections:

• cervical;
• lumbar;
• coccyx;
• chest;
• sacral.

There are 7 vertebrae in the cervical region, 12 in the thoracic region. The lumbar region consists of 5 vertebrae.

The thoracic spine is made up of 37 bones, including 24 ribs and the sternum.

A child has about 300-350 bones. As you grow older, some bones fuse and their number decreases. Bone tissue at the age of 25 years. During this period, the main growth of the body stops. The skeleton of a 25-year-old person consists of 206 bones, and this number remains unchanged until the end of life.

The human skeleton weighs only one-fifth of the total body weight.

Why do 90-odd more bones have more? The fact is that some bones are more similar in structure to cartilage. As cartilage grows, it becomes ossified, i.e. become ossified and their structure changes. During the process of ossification, bones fuse to form the human skeleton. This applies not only to the skeleton of the body. The newborn's skull is also divided into separate bones that allow the head to pass through the birth canal. During the first two years of life, the bones of the skull grow rapidly, becoming overgrown with connective tissue, although the sutures between the bones remain open for up to 20 years.

Some people may have a different number of bones than normal due to different growths, extra fingers or ribs.

Ensuring bone growth

Bones are made up of four types of tissue: periosteum, compact bone, cancellous bone, and bone marrow. The periosteum is the top layer of bone; it contains nerves and blood vessels that deliver nutrients to the bone tissue. This layer protects the bone marrow from damage. For healthy bones, the child must receive all the necessary micro- and macroelements and lead an active lifestyle. Physical exercise is beneficial. Fruits and vegetables and calcium-containing foods are essential for healthy bones. Sunlight provides the body with vitamin D, which helps the body absorb calcium. Without sunlight, bone tissue will not be healthy and strong.

It is important to prevent any bone injuries, especially fractures, in childhood. Parents should ensure that children wear protective equipment when riding a bicycle or rollerblading. When engaging in outdoor sports, it is also necessary to provide proper uniforms and other protective equipment, since in childhood the risk of injury is quite high. Children's bones grow quickly, so the healing process is faster than. However, it is up to the age of 20 that the skeleton begins to form, which will serve a person for the rest of his life.

Sources:

• How many bones does a person have?

Each fracture is unique, just as each human body is unique, so the time frame for restoring bone integrity can vary widely. Some bones can take more than six months to heal, others in just a few weeks. The speed of recovery is directly affected by the patient's age and the severity of the fracture.

Instructions

Until now, scientists cannot give a clear answer to the question of whether bones grow together. It has not been proven that any medications can speed up this process. Qualified doctors know that the integrity of bones is restored by the body itself, and the doctor’s job is to ensure that broken bones are rested and in the correct position to avoid the risks of incomplete or incorrect healing. The doctor must also stop possible purulent processes and damage to soft tissues in a timely manner. At the same time, there is simply no miracle that will restore the bone faster.

Medicine has experimentally established the following facts about the rate of bone fusion.

Number of fractures: one is faster than several, and if there are multiple, then some may not heal at all. The rate of fusion is significantly influenced by age. Bones such as the humerus, radius, and others grow together very quickly, regardless of age, but for example, the tibia, may not even heal. Dense bones heal more slowly than spongy bones. The more muscle there is around a broken bone, the faster it will be. In a healthy, strong person, the bone will heal faster than in a weak and exhausted person. The bones that make up the joint grow together slowly. Active development of the limb with the help of physical therapy and the patient’s activity in general have an extremely positive effect on the speed of recovery. Poorly or improperly secured fragments that are subject to unnecessary movements will heal much more slowly.

Bone restoration can be divided into four stages. Immediately after the fracture, fibers of new bone tissue are formed at the ends of the fragments, from which fibers of new bone tissue will subsequently form. The clot is filled with special cells - osteoclasts, which line the edges of the bone, and osteoblasts, which fill the gap between the fragments. After a few days, a granular bridge is formed between the fragments, which during the third stage thickens and becomes a fragile bone mass that can easily collapse with careless movement, so immobilization of fractures is absolutely necessary. The last stage is ossification, during this period the body actively supplies calcium to the fracture area using the circulatory system, which is why it is important to ensure good blood supply to the fracture site.

Helpful advice

The more diligently you follow the advice of your physical therapy instructor, the faster your bone will heal.

Bone fractures in most cases, especially in childhood, heal without deformation. Due to deteriorated blood circulation in the body with age, due to incorrect actions of the doctor, bone fractures may heal incorrectly.

Instructions

A bone fracture begins to heal almost immediately after the incident. There are four stages from injury to complete healing. At the first stage, the formation of a so-called clot occurs. This is a viscous blood mass that collects at the ends of broken bones. From these clots, the fibers formed will promote bone fusion, like an adhesive base.

The formation of the skeleton occurs in the 3rd week of embryonic development: initially as a connective tissue formation, and in the middle of the 2nd month of development it is replaced by cartilaginous tissue, after which the gradual destruction of cartilage begins and the formation of bone tissue instead. Ossification of the skeleton is not completed at the time of birth, so a newborn child's skeleton contains a lot of cartilage tissue.

The bone tissue itself differs significantly in chemical composition from the tissue of an adult. It contains a lot of organic substances, it does not have strength and is easily distorted under the influence of adverse external influences.

Young bones grow in length due to the cartilage located between their ends and the body. By the time bone growth ends, cartilage is replaced by bone tissue. During the period of growth, the amount of water in the child’s bones decreases, and the amount of minerals increases. The content of organic substances decreases. Skeletal development in men ends by the age of 20-24. In this case, the growth of bones in length stops, and their cartilaginous parts are replaced by bone tissue. Skeletal development in women ends by the age of 18-21.

Spinal column. The growth of the spinal column occurs most intensively in the first 2 years of life. During the first year and a half of life, the growth of various parts of the spine is relatively uniform. Starting from 1.5 to 3 years, the growth of the cervical and upper thoracic vertebrae slows down and the growth of the lumbar region begins to increase faster, which is typical for the entire period of growth of the spine. An increase in the rate of growth of the spine is observed at 7-9 years of age and during puberty, after which the increase in the growth of the spine is very small.

The structure of the tissues of the spinal column changes significantly with age. Ossification, which begins in the prenatal period, continues throughout childhood. Until the age of 14, only the middle parts of the vertebrae ossify. During puberty, new ossification points appear in the form of plates, which merge with the vertebral body after 20 years. The process of ossification of individual vertebrae is completed with the end of growth processes - by the age of 21-23.

The curvature of the spine is formed during the individual development of the child. At a very early age, when the child begins to hold his head up, a cervical curve appears, convexly directed forward (lordosis). By 6 months, when the child begins to sit, a thoracic curve forms with a convexity backward (kyphosis). When a child begins to stand and walk, lumbar lordosis forms.

By the age of one year, all the curves of the spine are already present. But the resulting bends are not fixed and disappear when the muscles relax. By the age of 7, there are already clearly defined cervical and thoracic curves; fixation of the lumbar curve occurs later - at 12-14 years. Disturbances in the curvature of the spinal column, which can arise as a result of improper seating of the child at the table and desk, lead to adverse consequences in his health.

Rib cage. The shape of the chest changes significantly with age. In infancy, it is as if compressed from the sides, its anteroposterior size is larger than the transverse one (conical shape). In an adult, the transverse size predominates. During the first year of life, the angle of the ribs relative to the spine gradually decreases. According to the change in the chest, the volume of the lungs increases. Changing the position of the ribs helps to increase the movement of the chest and allows for more efficient breathing movements. The conical shape of the chest lasts up to 3-4 years. By the age of 6, the relative sizes of the upper and lower parts of the chest characteristic of an adult are established, and the inclination of the ribs sharply increases. By the age of 12-13, the chest takes on the same shape as that of an adult. The shape of the chest is influenced by exercise and posture.

Skeleton of limbs. The clavicles are stable bones that change little during ontogenesis. The shoulder blades ossify in postnatal ontogenesis after 16-18 years. Ossification of free limbs begins in early childhood and ends at 18-20 years of age, and sometimes later.

The carpal bones of a newborn are just emerging and become clearly visible by the age of 7 years. From 10-12 years of age, gender differences in ossification processes appear. In boys they are late by 1 year. Ossification of the phalanges of the fingers is completed by the age of 11, and of the wrist by 12 years. Moderate and accessible movements contribute to the development of the hand. Playing musical instruments from an early age delays the process of ossification of the phalanges of the fingers, which leads to their lengthening (“musician’s fingers”).

In a newborn, each pelvic bone consists of three bones (iliac, pubic and ischial), the fusion of which begins at 5-6 years and is completed by 17-18 years. During adolescence, the sacral vertebrae gradually fuse into a single bone - the sacrum. After 9 years, differences are noted in the shape of the pelvis in boys and girls: boys have a higher and narrower pelvis than girls.

The human foot forms an arch that rests on the heel bone and the anterior ends of the metatarsal bones. The arch acts like a spring, softening the shock of the body when walking. In a newborn child, arching of the foot is not pronounced; it develops later, when the child begins to walk.

Scull. In a newborn, the cranial bones are connected to each other by a soft connective tissue membrane. These are fontanelles. The fontanelles are located at the corners of both parietal bones; There are unpaired frontal and occipital and paired anterior lateral and posterior lateral fontanelles. Thanks to the fontanelles, the bones of the roof of the skull can overlap each other with their edges. This is of great importance when the fetal head passes through the birth canal. Small fontanelles overgrow by 2-3 months, and the largest one, the frontal one, is easily palpable and overgrown only by one and a half years. In children at an early age, the cerebral part of the skull is more developed than the facial part. The bones of the skull grow most rapidly during the first year of life. With age, especially from 13-14 years, the facial region grows more vigorously and begins to dominate over the brain. In a newborn, the volume of the cerebral part of the skull is 6 times larger than the facial part, and in an adult it is 2-2.5 times larger.

Head growth is observed at all stages of child development; it occurs most intensively during puberty. With age, the relationship between head height and height changes significantly. This ratio is used as one of the normative indicators characterizing the age of the child.

Development of the muscular system

Muscle development begins in the 3rd week. Almost all striated muscles originate from myotomes. In a 4-week embryo, myotomes consist of mononuclear round cells, later - of spindle-shaped cells, myoblasts. They multiply intensively and migrate to adjacent areas, including the limb buds. At the age of 5 weeks, the synthesis of muscle proteins begins in myoblasts - myosin, actin, etc., from which contractile filaments - myofilaments are formed.

At 5-10 weeks, multinucleated myotubes are formed. The formation of myofilaments and then myofibrils is enhanced in them. Later (20 weeks), the myotubes turn into muscle fibers. Myofibrils fill their internal space, and the nuclei are pushed under the sarcolemma. The contraction is recorded after the formation of myofibrils (week 5) and clearly appears at 10-15 weeks. Muscle contraction during this period contributes to the proper formation of the skeleton. The motor activity of the fetus manifests itself either in short-term tremors or in powerful extension movements involving all muscle groups.

The development of muscle fibers does not occur simultaneously. In the fetus, muscle fibers are primarily formed in the tongue, lips, diaphragm, intercostal and back muscles. In the limbs, fibers develop later, first in the muscles of the arms, then the legs. Thus, the muscles that are more necessary to perform important functions are formed first.

The most intense muscle growth occurs at 1-2 years. The increase in length occurs due to growth points at the ends of the fibers adjacent to the tendons. Muscle growth in thickness occurs due to an increase in the number of myofibrils in a muscle cell: if a newborn has from 50 to 150 in a muscle cell, then a 7-year-old child has from 1000 to 3000. The number of cells increases in the first 4 months after birth, and then does not change. At the age of 12-15, another transformation of the muscle structure occurs. Muscle cells fit very tightly to each other, lose their round shape and look flattened in a cross section.

As a child develops, individual muscle groups grow unevenly. In infants, first of all, the abdominal muscles develop, and later the chewing muscles. By the end of the first year of life, in connection with crawling and the beginning of walking, the muscles of the back and limbs noticeably grow. Over the entire period of child growth, muscle mass increases 35 times. During puberty (12-16 years), along with the lengthening of the tubular bones, the muscle tendons also lengthen. The muscles at this time become long and thin, and adolescents look long-legged and long-armed. At 15-18 years of age, further growth in muscle diameter continues. Muscle development continues until 25-30 years of age. A child's muscles are paler, softer and more elastic than those of an adult.

Muscle tone. During the neonatal period and in the first months of life of children, the tone of skeletal muscles is increased. This is due to increased excitability of the red nucleus of the midbrain. As the influences coming from the brain structures through the pyramidal system and regulating the functional activity of the spinal cord increase, muscle tone decreases. A decrease in tone is observed in the second half of a child’s life, which is a necessary prerequisite for the development of walking. Muscle tone plays an important role in the coordination of movements.

Muscle strength. An increase in muscle mass and structural transformations of muscle fibers with age lead to an increase in muscle strength. At preschool age, muscle strength is insignificant. After 4-5 years, the strength of individual muscle groups increases. Schoolchildren aged 7-11 years still have relatively low levels of muscle strength. Strength and especially static exercises cause them to tire quickly. Children of this age are more adapted to short-term speed-strength dynamic exercises.

Muscle strength increases most rapidly during adolescence. In boys, the increase in strength begins at 13-14 years old, in girls earlier - from 10-12 years old, which may be due to the earlier onset of puberty in girls. At the age of 13-14, gender differences in muscle strength clearly appear; the relative muscle strength of girls is significantly inferior to the corresponding indicators of boys. Therefore, in classes with teenage girls and young women, the intensity and severity of exercises should be dosed especially strictly. From the age of 18, strength growth slows down and ends by the age of 25-26. It was found that the rate of recovery of muscle strength in adolescents and adults is almost the same: in 14-year-olds - 97.5%, in 16-year-olds and adults - 98.9% of the initial values.

The development of strength in different muscle groups occurs unevenly. The strength of the muscles that extend the body reaches its maximum at 16 years of age. Maximum strength of the extensors and flexors of the upper and lower extremities is observed at 20-30 years of age.

Speed, precision of movement and endurance. The speed of movement is characterized by both the speed of a single movement and the frequency of repeated movements. The speed of single movements increases at primary school age, approaching the adult level at 13-14 years of age. By the age of 16-17, the rate of increase in this indicator decreases slightly. By the age of 20-30, the speed of a single movement reaches its greatest value. This is due to an increase in the speed of signal transmission in the nervous system and the speed of the process of excitation transmission at the neuromuscular synapse.

With age, the maximum frequency of repetitive movements increases. The most intensive growth of this indicator occurs at primary school age. In the period from 7 to 9 years, the average annual increase is 0.3-0.6 movements per second. At 10-11 years of age, the growth rate decreases to 0.1-0.2 movements per second and increases again (to 0.3-0.4 movements per second) at 12-13 years. The frequency of movements per unit time in boys reaches high levels at 15 years of age, after which the annual increase decreases. In girls, this indicator reaches its maximum values ​​at 14 years of age and does not change further. The increase in the maximum frequency of movements with age is explained by the increasing mobility of nervous processes, which ensures a more rapid transition of antagonist muscles from a state of excitation to a state of inhibition and back.

The accuracy of movement reproduction also changes significantly with age. Preschoolers 4-5 years old cannot make subtle, precise movements that reproduce a given program. At primary school age, the ability to accurately reproduce movements according to a given program increases significantly. From 9-10 years old, the organization of precise movements occurs like an adult. In improving this motor quality, a significant role is played by the formation of central mechanisms for organizing voluntary movements associated with the activity of the higher parts of the central nervous system.

Over a long period of ontogenesis, endurance is also formed (a person’s ability to perform one or another type of mental or physical activity for a long time without reducing their effectiveness). Endurance for dynamic work is still very low at 7-11 years of age. From the age of 11-12, boys and girls become more resilient. Walking, slow running, and skiing are good ways to develop endurance. By the age of 14, muscular endurance is 50-70%, and by the age of 16, about 80% of the endurance of an adult.

Endurance to static forces increases especially intensively in the period from 8 to 17 years. Its most significant changes are observed in primary school age. In 11-14 year old schoolchildren, the most resilient muscles are the calf muscles. In general, endurance by the age of 17-19 is 85% of the adult level, and it reaches maximum values ​​by the age of 25-30.

The rate of development of many motor qualities is especially high at primary school age, which, given the interest of children in physical education and sports, provides grounds for purposefully developing motor activity at this age.

The skeleton is a particularly important part of the complete, healthy functioning of the human body. Thanks to bones, the body is always in shape and in the desired position. Bones form the skeleton, which in turn also performs the protective function of internal organs and systems from external influences. All this applies to both adults and children from the womb.

Formation of the fetal skeleton

More than 70% of the bones consist of very strong bone tissue, which contains many minerals. The main ones include: magnesium, phosphorus and calcium. Other elements are also necessary for the full formation of the fetal skeleton: zinc, copper, aluminum and fluorine. The fetus receives these and other substances through the placenta from the mother’s body. Therefore, it is extremely important for pregnant women to eat well and eat well. Starting from the fifth week of pregnancy, the foundations of cartilage are laid in the fetus - the future bones of the spine and shoulder girdle. The outlines of the pelvic girdle also appear. The fetus, which is already 9 weeks old, has formed fingers and jaw bones. Many people know that a newborn baby has more bones than an adult. This is due to the fact that in the future the cartilage will grow together to form one bone. The complete formation of the skeleton will occur at 24 years of age.

How many bones does a child have?

Many parents are convinced from their own experience that their child’s bones are more likely to bend than to be injured. Without taking into account, of course, serious damage. Very often, newborns fall out of bed or sofa, while “pah-pah” everything is fine. All this is because their skeleton is dominated by cartilage, which will then strengthen and become bone. So how many bones does a baby have? A newborn baby has 300 fragile bones in its small body. And only by the age of 24-25, 206 strong, durable bones will be formed from them.

This process occurs due to the intake of calcium and other necessary substances into the body.

Bone injuries in a child

How many bones are in the body of a small child - it’s clear, now about their injuries. Childhood injuries, to the great joy of parents, are quickly restored.

This is all due to the fact that in a child’s body there are cells responsible for the structure of bone tissue. And if it happens that the child is injured, these cells end up on the injured area. Thus, even a fracture in a child will heal much faster than in an adult. A child's injury will go away after 2-4 weeks, an adult's - 6-8. All young mothers and others need to know how many bones are in a child’s body. This will allow you to be more educated in this area and provide the necessary assistance to the child in case of injury.

Difference between bone of an elderly person and a child

We figured out how many bones are in a child’s skeleton. Now the question that worries many is: “What is the difference in the skeleton of an elderly person and a child?” Children's bones are much thinner than those of adults, including the elderly. Thanks to this, the child’s motor system is much more mobile and elastic. Closer to 12-13 year olds, children are almost completely similar to adults. However, cartilage is still found in some places. During adulthood and closer to old age, the relief of the cranial bones noticeably smoothes out.

Also, when teeth are lost, the weight of the skull decreases, which can provoke malocclusion and cause facial asymmetry.

The most pronounced changes in skeletal structure with age occur in the spine. After 40-50 years, this part of the skeleton becomes more compressed and slightly shorter than it was before. This is due to the fact that the intervertebral discs and vertebrae fit closer together. After 60 years, bone tissue begins to grow, and spine-like formations appear throughout the body.

So, the main differences between the skeleton of an elderly and a small person:

1. The main and first difference is, of course, quantity. How many bones do a small child and an elderly person have? Child - 300 dominoes, adult - 206.
2. The bone tissue of a child is richer in spongy substance than the bone of an elderly person.
3. Another important difference is mobility. The child's skeleton is more active and elastic, which cannot be said about the skeleton of older people.
4. With age, tissue changes, which leads to weakening of the skeletal bones. A noticeable decrease in calcium and fluorine in the body first makes itself felt.

The skeletal system of a newborn is characterized by the presence of a large amount of cartilage tissue,

reticular structure of bones, in which the Haversian canals have an irregular shape, rich in vascular

network in the neck of the bone (areas with large proliferative development), significant thickness

periosteum. The weight of cartilage and bones that make up the skeleton is 15-20% of the total body weight. Process

Skeletal ossification begins with the appearance of ossification nuclei in connective tissue and cartilaginous models

bones. Ossification nuclei that appear in intrauterine life are called primary nuclei, and those

that appear after birth are secondary. The skeleton develops completely when 806 nuclei appear

ossification.

The order of appearance of ossification nuclei is hereditary, but the time of appearance and their speed

development depend on a number of factors: ethno-territorial, gender, social conditions.

Typically, in girls, the time of appearance of ossification nuclei and their development occurs earlier than in boys. IN

in infancy, the difference in the time of appearance of ossification nuclei is approximately 1 week; in children up to 5

years is a year or more. In long tubular bones, ossification of the diaphysis occurs in the prenatal period.

period. By the time of birth, ossification points may appear in the distal epiphysis of the femur and

proximal tibial epiphysis, which serves as a sign of full-term fetus. Further sequentially

ossification points appear in the apophyses, the metaphysis is the last to ossify, which indicates the end

skeletal growth.

In a newborn, there is only 28 g of Ca in the skeleton, in a one-year-old it increases 3 times, at 18 years old - 1035 g of Ca.

Features of the newborn's skull.

The skull of a newborn is relatively large. The facial region is much smaller than the brain

(ratio 1/4, in an adult - 1/2). The predominance of the brain region is associated with the rapid development of the central nervous system

(brain) in the prenatal period. Underdevelopment of the alveolar processes, lack of teeth,

underdevelopment of the paranasal sinuses and the nasal cavity as a whole, smoothed relief of the bones of the facial skull

cause smaller sizes of the facial skull.

The bones of the roof of the skull contain a large amount of connective tissue. The edges of the bones are smooth, the spaces

between them are filled with connective tissue, which creates relative mobility of the bones for

adaptation of the head to the birth canal (the phenomenon of conoriguration). In the region of the corners of the parietal bone

The connective tissue is preserved in the form of fontanelles. The mastoid and styloid fontanels have small

sizes, and normally close by the time of birth (or in the first month after birth), the occipital - in

the first half of the year, the frontal has the shape of a diamond, the larger sizes close in the second year of life. Scull

the newborn has the appearance of a pentagon, since the parietal, occipital and frontal tubercles are well defined

(primary ossification points of the integumentary bones of the skull).

The bones of the skull base retain a large amount of cartilaginous tissue, which in postnatal

period it ossifies and remains in the form of temporary and permanent synchondrosis. Cells of the mastoid process

are in their infancy, their constant formation begins by the age of 3.

Scull from the moment of birth to the end of life undergoes great changes.

The first period is from birth to 7 years.

In the first 6 months after birth, the volume of the brain skull increases 2 times, the cranial

pits. In the first year of life, the cartilage in the occipital bone and the membranous tissue of the skull disappear. Begins

formation of seams. Bones become more prominent.

From 1 to 2 years the volume of the cranium triples, and up to 5 years it reaches? adult skull volume

person. There is a uniform growth of the brain and facial skull, the head becomes wider. Base

reaches the size of an adult. The diameter of the foramen magnum is finally formed. Due to

tooth growth, the height of the upper and lower jaw increases, which is reflected in the shape of the face, mouth and nose

cavities (development of paranasal sinuses). An important point is the formation of seams (approximately 3

of the year).

Sufura metorica closes by 5 years. Early closure of sutures leads to the formation of a conical shape

heads.

Second period from 8 to 13-14 years - a relative slowdown in the growth of skull bones, although it is noted

significant enlargement of the nasal cavity, upper jaw, orbits.

The third period from the onset of puberty (14 -16 years) to 20 - 25 years when growth ends.

The facial skull grows more intensively relative to the brain (especially in men). Increases

the base of the skull not only in the transverse, but also in the anteroposterior direction. The airways are formed

sinuses, tubercles, protrusions, glabella and grooves.

AGE FEATURES OF CONNECTIONS.

A newborn has all types of joints with the exception of sutures. Synovial joints or

the joints of a newborn are basically formed and have all three articular components - the joint capsule,

articular surfaces and joint space. The relief of surfaces in many joints is not clearly expressed, a number

joints has incongruent articular surfaces. Articular discs, menisci, articular lips are thin,

not fully formed. The joint capsules of the joints are taut, and most ligaments are different

insufficient differentiation of the loosely arranged fibers that form them.

The development of joints is most intensive at the age of 2-3 years due to the increase in motor

activity. In children 3 - 8 years old, the range of movements in the joints increases significantly, and at the same time the process

collagenization of joint capsules and ligaments. In the period from 9 to 12 years, the process of restructuring of articular cartilage

slows down. The formation of articular surfaces, capsules and ligaments is completed mainly at 13-16 years of age.

Spinal column.

The spine of a newborn is not straight, but also does not have clear bends. The child is only 3-4 months old

begins to hold the head up and a cervical bend appears - cervical lordosis (bending forward). When does a child start

sit (4-6 months of life), thoracic kyphosis (posterior bending) forms. Lumbar lordosis appears later,

which is formed in connection with the transition to a vertical position. Final formation of bends

the spine ends by 18-25 years.

Intervertebral discs in a newborn are relatively thicker than in an adult and make up about half

the length of the entire spinal column. The nucleus pulposus is very developed in a child and contains a large amount

water (88%). The annulus fibrosus is well vascularized until adolescence, vascular development is reversed

begins at approximately 13 years of age and ends completely by age 25. Thanks to the large volume

intervertebral cartilage, the mobility of the spine is significantly greater compared to an adult.