The bones of the skull play a crucial role in protecting the most important human organ - the brain. They are divided into paired and unpaired. They form the cavity in which the brain, organs of vision, balance, hearing, taste, smell are located. The bones located at the base of the skull have holes through which the nerves exit, and arteries pass to the brain.
The cranium has 2 sections: the front (consists of 15 bones) and the brain (consists of 8 bones). The facial section is the bone base of the person’s face, the initial parts of the respiratory and digestive systems. These bones of the skull are located under the medulla. A significant part is occupied by the chewing apparatus, which includes the upper (paired bone) and lower jaw (unpaired).
The upper jaw forms the walls of the orbits, the hard palate, the side walls of the cavity and the openings of the nose. The following processes depart from her "body": zygomatic, frontal, alveolar, palatine.
The lower jaw is the only mobile bone of the skull, which, together with the temporal bones, is involved in the formation of the temporomandibular joints. She has a curved body on which the alveoli for the teeth, articular and
coronoid processes are located (chewing muscles are attached to them).
Small
facial bones of the skull: paired - palatine, nasal, lower shell, zygomatic, lacrimal; unpaired - opener and hyoid. They are part of the oral and
nasal cavities, as well as the orbits. This also includes a curved arcuate hyoid bone with processes (lower and upper horns).
The brain section of adults consists of the occipital, frontal, sphenoid, ethmoid, parietal and temporal bones. The unpaired frontal bone forms the upper wall of the orbits and the front of the brain. It has the nasal and orbital parts, frontal scales and frontal sinus.
The occipital bone makes up the lower occipital region of the skull. It has the main part, occipital scales and lateral masses. The sphenoid bone is located at the base of the skull. It has a complex shape and consists of a body having 3 paired processes. There is a sphenoid sinus in her body.
The ethmoid bone is unpaired. It is an integral part of the nasal cavity and the walls of the orbits. It has a horizontal grid plate with holes; perpendicular plate dividing the nose into 2 cavities; trellised labyrinths with middle and upper nasal concha which form nasal cavities.
The parietal bone is paired. It forms the upper lateral parts of the cranial vault. In shape, it resembles a quadrangular plate, concave from the inside and convex from the outside.
The temporal paired bones of the skull are involved in the formation of the jaw joint. They distinguish a pyramid, scaly and drum parts. On their lateral surfaces there are holes in the ear canal. The temporal bones are pierced by several channels through which blood vessels and nerves go.
In the brain skull, the upper part (roof or arch) is divided between the lower part (the base of the skull). The bones of the arch are connected using continuous fibrous sutures, and the bases form synchondrosis (cartilage joints). The frontal, occipital and parietal bones are connected by serrated sutures, and the bones of the facial section have flat and harmonious sutures. The temporal bone with the sphenoid and parietal is connected by a scaly suture. With age, cartilage is replaced by bone tissue, and neighboring bones are fused.
The air bones of the skull differ from others in that they have cavities that are lined with mucous membranes and filled with air. These include the frontal, sphenoid, ethmoid bones and the upper jaw.