The human skull is the skeleton of his head. This skeleton is divided into the front and brain parts.
In the brain area, the skeleton of the head according to the formis close to the ball. This part includes two parietal, frontal, occipital, two temporal and other bones of the human skull. By appearance all the elements are represented by thick enough curved plates. These bones are called flat. Their task is to protect the brain from damage.
Separate bone elements in the skeleton of the headare connected by means of seams. Such a joint is called immovable. The seam is formed by the cut edges of two adjacent elements. In this case, the notches of one of them include the teeth of the other.
The human skull in the brain hasrelatively smooth surfaces (lateral and upper). The base of the cerebral part is covered with roughnesses and various protuberances. This is due to the fact that the human skull in this place is connected to the muscle fibers. There are also holes in the base. Nerves and blood vessels pass through them. Approximately in the center of this part of the skeleton of the head is a large opening (occipital), through which the connection of the brain and spinal cord occurs.
On the boundary of the side surfaces and the basethe skull has auditory orifices (external). The lower surface of the occipital bone element has articular processes that lie on both sides of the occipital orifice. With the help of these processes, the human skull is connected to the spine.
The face of the skeleton of the head includescomposition of paired bone elements. These include the maxillary, nasal, zygomatic, palatine and other bones. The mandibular bone element is not paired.
In the obverse region of the skeleton of the head are oral, nasal cavities, as well as orbits.
The eyes are represented by a deep hollow. In it lies the eyeball, as well as its muscles, vessels and nerves.
The nasal cavity is opened from the front by a hole inthe surface of the skeleton of the head. Behind the nasal cavity is connected with the pharynx through two holes. The right and left half of the cavity are formed by the separating bone septum. In each of the halves, through the three bones, nasal passages are formed.
The oral cavity is separated from the nasal by the palatine bone elements and processes of the maxillary bones. The edges of the lower and upper jaws restrict the mouth from the sides.
The human skull has the same parts and elements,that the skeleton of a head of mammals. However, an essential feature of the skeleton of the human head is the extremely developed brain portion. Mammals have a more developed facial part.
Elements forming the skull of the newbornare in a state of incomplete ossification. They in their composition have connective tissue and cartilage. Occipital, frontal and other bone elements contain several components. At the edges of the elements of the skeleton of the head of the newborn there are no teeth. Thus, the connection is made by means of strips of connective tissue membrane, and not seams. In areas where convergence of the corners of several bone elements occurs, the membranes expand, forming fontanelles.
With the development of the child, some of the bones are articulated with each other, the formation of stitches, the fontanels overgrow. Thus, the ossification process is gradually being completed, the growth of bones begins.
The skeleton of the head, as well as of the entire body, onthroughout human life is undergoing changes. So, from the age of thirty, as a rule, the process of overgrowing sutures begins. When a person reaches old age, the teeth begin to fall out and the cells in which they are located disappear.
