Everyone can perfectly imagine the human skeleton, thanks to the numerous photographs and drawings that each of us saw in school. But do we know that the adult human skeleton is made up of many different bones, each with a specific function?
The human skeleton: what does it consist of?
The human skeleton is its support. It is not only capable of acting for the human body as a repository for its internal organs and systems, but also is a place of attachment for its muscles.
With the help of the skeleton, a person is able to perform various movements: walk, jump, sit, lie down and much more. An interesting fact is that the human skeleton - the connection of bones - is formed in a child who is still in the womb. True, at first it is only cartilaginous tissue, which is replaced in the course of his life by bone. In a baby, the bones practically do not have a hollow space inside. It arises there in the process of human growth. One of the most important functions of the human skeleton is the formation of new blood cells, which are produced by the bone marrow,located right in it. A feature of the bones of the human skeleton is the preservation of a certain shape during life (and therefore continuous growth and development). The list of bones of the human skeleton includes more than 200 items. Many of them are paired, while the rest do not form pairs (33-34 pieces). These are some of the bones of the sternum and skull, as well as the coccyx, sacrum, vertebrae.
Functions of human limbs
It is very important to know that the process of evolution, i.e. the continuous development of man, has left a direct imprint on the functioning of many of his bones.
The upper part of the human skeleton with its movable limbs is designed mainly for human survival in the world. With the help of his hands, he is able to cook food, do homework, serve himself, etc. There are also bones of the lower extremities of a person. Their anatomy is so thought out that a person is able to stay upright. At the same time, they serve as the basis for movement and support for him. It should be noted that the lower limbs are less mobile than the upper ones. They are more massive in weight and density. But along with this, their functions are very important for a person.
Human lower limb skeleton
Consider the human skeleton: the skeleton of the lower limb and upper limb is represented by a belt and a free part. In the upper section, these are the following bones: pectoral girdle, shoulder blades and collarbone, humerus and forearm bones, hand. The bones of the human lower limb include: the pelvic girdle (or pairedpelvic bones), thigh, lower leg, foot. The bones of the free lower limb of a person, as well as the belts, are able to support the weight of a person, which is why they are so important to him. After all, in fact, only with the help of these connections can it be in a vertical position.
Pelvic girdle (paired pelvic bones)
The first component, which is the basis that forms the bones of the girdle of the human lower limb, will be the pelvic bone.
It is she who changes her structure after puberty of any adult. Until this age, it is said that the pelvic girdle consists of three separate bones (ilium, pubic and ischial), interconnected by cartilaginous tissue. Thus, they form a kind of cavity where the femoral head is placed. The bone pelvis is formed by connecting the bones of the same name in front. Behind, it is articulated with the help of the sacrum. As a result, the pelvic bones form a kind of ring, which is a repository for the internal organs of a person.
Thigh and Patella
The bones of the girdle of the lower limb of a person are not as mobile as the rest of it, which is called just that - the free lower limb. It consists of: thigh, lower leg and foot. The femur, or femur, is a tubular bone. It is also the largest and longest of all the bones that the human body is endowed with. In its upper part, the femur is connected to the pelvic girdle with the help of a head and a long thin neck. Where the neck passes into the main part of the femur, it hastwo large bumps. It is here that the bulk of the muscles of the lower extremities of a person is attached. From top to bottom, the femur becomes thicker. There are also two elevations, thanks to which the thigh is connected, as a result, with the patella and lower leg. The patella is a flat, rounded bone that flexes the leg at the knee. The bones of the human lower limb, namely the femur and patella, have the following functions: the place of attachment of the bulk of the muscles located on the legs, and the possibility of bending the leg.
Shin
The human lower leg consists of two bones: the tibia and the fibula. They are located next to each other.
The first one is quite massive and thick. From above, it connects to the outgrowths (condyles) of the femur and the head of the fibula. From top to bottom, the tibia turns on one side into the medial malleolus, and on the other, it is located directly under the skin. The fibula is smaller in size. But at the edges it is also thickened. Due to this, it is connected from above to the tibia, and from below it forms the lateral malleolus. It is important that both components of the lower leg, which are also the bones of the human lower limb, are tubular bones.
Human foot bones
The bones of the human foot are divided into three main parts: the bones of the tarsus, metatarsus and phalanges of the fingers. It is important to note that the foot is a free bone of the human lower limb. The first of them include seven bones, the main of whichis a bone called the talus and forming the ankle joint, and the calcaneus. Next are the bones of the metatarsus. There are only five of them, the first one is much thicker and shorter than the others. The toes are made up of bones called phalanges. The peculiarity of their structure is that the big toe contains 2 phalanges, the remaining fingers - three each.
Anatomy of the joints of the human lower extremities. Sacroiliac joint, pubic symphysis
I want to say right away that all the joints of the lower limb are very large compared to the joints of the upper limbs.
They have a large number of different ligaments, thanks to which the variety of movements that can be done with the help of a person's legs is carried out. The bones and joints of the bones of the lower limb were originally created in order to serve as a support for the human body and move it. Therefore, of course, they are reliable, strong and able to withstand heavy loads. Let's start with the uppermost, in terms of location, joints. With their help, the pelvic bones are connected, and the pelvis is formed in humans. In front, such a joint is called the pubic symphysis, and behind - the sacroiliac. The first was created on the basis of the pubic bones located towards each other. Strengthening of the pubic symphysis is formed due to a large number of ligaments. The sacroiliac joint is very strong and almost immobile. It is tightly fastened not only to the pelvic bones, but also to the lower spine with tight ligaments.
Human pelvis:big and small. Hip joint
It has already been described above that the bones of the girdle of the lower limb of a person are represented primarily by the pelvic bones. They, connecting with the help of the sacrum and the pubic symphysis, form the pelvis. This is, figuratively speaking, a ring that protects all the organs, vessels and nerve endings located inside from external influences. Distinguish between the large and small pelvis. In women, it is much wider and lower than in men. For the fair sex, everything is thought out to facilitate the birth process, so the pelvis has a more rounded shape and greater capacity.
The joints of the bones of the lower limb are also represented by one of the most famous representatives of this group - the hip joint. Why is he so famous? Dislocation of the hip joint is the most well-known defect in the development of the lower extremities, which can be detected literally a month after the birth of the baby. It is very important to do this on time, since this untreated diagnosis can bring a lot of trouble in adulthood. The hip joint consists of the socket of the pelvic bone and the head of the femur. The examined joint has many ligaments, thanks to which it is strong and quite mobile. Usually, experienced orthopedists can diagnose an anomaly in the development of the hip joint in childhood using a routine examination of the patient. Abduction of the legs to the sides in the supine position by 180 degrees is possible only with he althy hip joints.
Knee joint
Imagine a human skeleton. The connection of bones in the form of joints is necessary for a person to strengthen the connection of bones and create maximum mobility of all his limbs. An excellent example of such a joint is the knee joint. By the way, it is considered the largest joint in the human body. Yes, and its structure is very complex: the knee joint is formed with the help of the condyles of the femur, patella, tibia. The entire joint is wrapped in strong ligaments, which, along with ensuring the movement of the leg, keep it in the desired position. Thanks to him, not only standing, but also walking is carried out. The knee joint can produce various movements: circular, flexion and extension.
Ankle joint
This joint is used for direct connection of the foot and lower leg. Numerous ligaments are located around, which provide a variety of movements and the necessary stability to the human body.
Metatarsophalangeal joints
The studied joints are interesting in their shape, in comparison with other joints of the human lower limb. They are like a ball. Strengthening for them are ligaments on the sides and on the sole of the foot. They can move, although they do not differ in the variety of their movements: small abductions to the sides, flexion and extension. The human foot is made up of numerous (non-mobile) joints and ligaments. With their help, movement is carried out, while the human body has the necessary support. So, we can conclude that the bones of the girdle of the lower limb of a person are less mobile than the free bones of a similar department. But the functions of this are no less for either one or the other.
How do human limbs develop with age?
We all know that the human skeleton also undergoes certain transformations during life. The skeleton of the lower extremity undergoes strong changes with age. Bones that develop on the basis of connective tissue have three stages of their change: connective tissue, cartilage and bone tissue.
Pelvic bone: it is laid even during the intrauterine development of the fetus. Formed cartilaginous layers between the pelvic bones usually remain until puberty. Further, they ossify. Patella: ossification points can appear in a child as early as 2 years old, this completely occurs somewhere around 7 years old. Interestingly, the lower limbs of newborns grow much faster than those of adults. The peak of such rapid growth falls on the period of puberty: in girls - 13-14 years; for boys - 12-13 years old.
Remember that the human skeleton is subject to various injuries in the form of damage and even fractures. Since it is entrusted with the performance of so many important functions of the body, it must be protected. Eat right (food with sufficient calcium helps strengthen the skeleton), lead an active lifestyle (physical education and sports), monitor your he alth (check any violations in the functioning of the skeleton with a competent specialist) - all this should be done by every person. And then you will meet your old age cheerful, he althy and cheerful.
