From the article you will learn about the features of the structureskeleton of the head. The fact is that some of the bones of the cerebral cranium differ in structure from the facial one. How does this affect their functions? Let's look at it together.
The skeleton of the head, or skull, consists of 27 bones.It also includes a hammer, stapes and an anvil. These are auditory ossicles, which are located in the cavity of the middle ear. As part of the sensory system, they provide a perception of sound.
Now consider the parts of the skull:brain department and facial. In the process of anthropogenesis, the size of the first of them increased. This is due to the development of the brain. With the course of evolution, man began to create an artificial environment. He built himself a dwelling, grew plants, stored food. The powerful jaw has lost its importance. Therefore, the size of the facial skull has significantly decreased. Particularly well noticeable are these differences when comparing a man of skill and intelligence.
At first glance, it may seem that the skeletonthe head is formed by one large bone. In fact, its structure is like a mosaic. Some bones have their exact copy. They are paired, there are eight in all. The remaining seven are unpaired. Each of them has its own name, in most cases associated with the location. So, the frontal is an unpaired bone of the skull. And the temporal and zygomatic have their analogs.
This part of the skull consists of 15 bones. The largest of these are the cheekbones and jawbones. We will list not the twin bones of the skull of this department:
To the bony bones of the facial division are:
Bones of the skeleton have different types of connection.They depend on the functions performed. For example, limb bones form joints - movable joints. The elbow, knee, ankle, etc. They make possible the movement of individual parts and the whole body in space. The vertebrae are connected in a semi-mobile manner. Between them are cartilaginous plates. This structure provides elasticity and cushioning.
But the bones of the skull are connected immovably. Thanks to this, the brain is reliably protected from mechanical damage. This type of joint is called a seam. It is also characteristic of pelvic bones.
Sutures in children have an elastic structure.With age, they ossify and become more durable. Depending on the pattern, which is formed during the connection of bones, distinguish between flat, scaly and serrated sutures.
All the bones of the cerebral skull, as well as the facial,are connected motionless, except the lower jaw. It is an unpaired bone of the skull. Despite the fact that there is an upper jaw, we were not mistaken. How is this possible. The upper jaw consists of two identical bones, connected by a seam. Thus, it is a steam room by itself.
The lower jaw is fastened with the aid ofthe joint. This is very important for human life. Thanks to the movements of the lower jaw, a person is able to chew food and pronounce sounds. These functions are associated with a decrease in the size of this bone in the process of evolution. After all, its massiveness would greatly complicate the chewing and speed of pronunciation. In addition, people began to eat chopped and thermally processed food. So the lower jaw has got the optimum sizes.
During a person's life, the skeleton of the headundergoes significant changes. Its weight during the growth of the body increases from 300 to 1,400 g. In addition, the baby's brain department is much more facial. In this period the jaws are still underdeveloped. Between the bones of the occipital region are the areas consisting of cartilaginous tissue. This is the fontanel. These sites have an important biological significance. They provide a narrowing of the cranium during movement of the fetus along the narrow sexual pathways.
In the places of fontanelles the baby's brain is protectedonly by soft connective tissues. Therefore, any blow or deformation can be deadly. There are only two. The large one is located between the frontal, which is the unpaired bone of the skull, and the parietal. Dimensions of this fontanelle reach 2 cm in diameter. In colloquial speech, the place of its location is called the "crown".
A small fontanel is on the back of the head.Children who were born on time, it is already closed. Otherwise, it grows to a maximum of three months. The large fontanel will grow to about one-year-old child. The intensity of this process depends on the degree of development of the fetus and its provision with calcium.
Another value of fontanel is thermoregulation.Diseases of children are often accompanied by a significant increase in body temperature. This is very dangerous, since at high values it can lead to clotting of the protein. In the fontanel area, the brain tissue is naturally cooled.
This part of the skeleton of the head is more massive. Here the unpaired bone of the skull is:
The parietals include parietal and temporal. In the brain department, the base and the vault are distinguished.
Despite the general outline of the structure, the skull of men andwomen has its own distinctive features. Thus, the first are more expressed superciliary arches and paranasal sinuses, larger than the orbit. And the bones of the skull in the male half of humanity are of great thickness. Women have a smaller capacity of the skull. But this is not due to mental abilities, but to the overall size of organisms.
