The structure of the skull

The structure of the skull is studied not only by anthropologists, doctors and pathologists, but also by representatives of creative professions - artists, sculptors. The skull is not just complex in structure, despite its apparent strength, it is quite fragile, although it is designed to protect the brain from impacts and injuries. The complex structure of the skull is due to the fact that the brain located in it must constantly be in touch, communicate with the human body. Biochemical resources flow to the brain every second through a branched vascular system. In order for this communication to be continuous and physiological, the skull has canals, holes, pits, and winding passages.

Anatomically, the structure of the skull is divided into two sections: the cranial vault and the facial part. The skull also has a base and a roof. The cranial bones are flat and quite dense, they are connected by a serrated suture, similar to the familiar zipper. The junction has a layer of fairly elastic embryonic connective tissue (mesenchyme). This tissue, like an additional adhesive layer, firmly connects the cranial bones together. The only bones of the skull that are prone to movement are the jaws and the occipital bone, which connects to the first cervical vertebra.

Babies whose embryonic tissue, the mesenchyme, has not yet ossified have a more fragile skull structure, which helps them move along the birth canal without damaging the canal itself or the head itself. These fragile areas of the infant skull are called fontanelles. The most extensive frontal fontanelle ossifies after one and a half years, the smaller but more vulnerable occipital fontanelle only by two years.

As soon as the baby's dental skeletal system is formed and teeth begin to appear, the facial part of the skull begins to overtake the part where the brain is located in development.

The human head consists of 29 bones, distributed as follows:

• cranial – 22 bones;
• ear (hearing aid) – 6 bones;
• bone under the base of the tongue (hyoid) – 1.

The structure of the skull can be divided into two structural categories: the vault or braincase and the facial part.

The cranial vault, the axial skull, is eight main bones. Since the cranial vault performs a protective function, protecting the brain from impacts, its bones are very strong and much thicker than the facial bones. The bones of the vault consist of specific double plates, which are filled with a spongy substance - diploe. Many capillaries, vessels and nerve endings pass through the entire spongy tissue, which constantly nourish both the bone marrow and the internal parts of the cranial bones.

Structure of the cranial vault:

• The bone that forms the forehead is the frontal bone;
• The two bones that form the parietal part are the parietals;
• The two bones that form the temples are the temporal bones;
• An unpaired bone, called the sphenoid, consisting of a body, lesser wings, greater wings, and processes;
• The bone that forms the back of the head is the occipital bone.

The facial part of the skull or visceral skull is also designed to protect the sensory organs from the effects of an aggressive external environment. The appearance, or rather the face of a person, depends on how the facial bones are located and related to each other. In addition to the bones that form the nose, mouth and throat, the facial structure includes a standard set of teeth - 16 pieces for the upper and lower jaws. The teeth are attached to the jaw sockets with the help of the periosteum. The teeth, in turn, also consist of specific bone tissue, which is enriched with phosphates. The health of a person's teeth depends on the quality of dentin - dental bone tissue.

Structure of the facial part of the skull:

• The two bones that form the nose are the nasal bones;
• The bones that form the cheekbones are the zygomatic bones;
• Upper jaw;
• Lower jaw.

The structure of the skull and its formation depends on the age of the person:

• The growth of the skull is intense from the day of birth until 7-8 years. During the first year of life, the bones of the skull grow evenly, up to three years the back of the skull increases greatly - this is due to the fact that the child begins to walk. Also during this period, the facial part of the skull actively develops due to the growth of teeth and the formation of chewing muscles. At seven years old, the child has a skull base that is almost identical to an adult.
• The growth of the skull slows down somewhat in the period from 8 years to 13-14 years. At this time, the body is busy with another important matter - the formation of the sexual organs and systems, their maturation. The volume of the cranial vault, as a rule, does not exceed 1250-1300 cm ³.
• At the end of puberty, the frontal and facial parts of the skull actively develop. In the stronger sex, the facial bones stretch in length, in girls this process is not so intense, the childish roundness remains. The male skull is slightly larger than the female one both in size and in capacity. In women, the volume does not exceed 1345 cm ³, in men the volume reaches 1600 cm ³. However, in the weaker sex, the bones of the brain part of the skull are more developed, and in men - the facial part.
• The skull changes its structure in old age. This is due to both the loss of teeth and the atony of the masticatory muscles. The bones of the skull lose their former elasticity and become vulnerable and fragile.

The structure of the skull can also depend on race and certain types of congenital pathologies.

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