The human skull is not only the most importantbone formation, but also the most visually noticeable. Therefore, all his changes can not pass unnoticed. The stages of such transformations are quite relative and each person is individual, but there are general principles depending on age.
During the life of the human skull is exposeda lot of changes. This primarily concerns its appearance. Conventionally, there are five large periods of such transformations. Consider each of them in more detail.
The first period
This period is the most active stage.head growth and lasts for the first seven years of a person’s life. From the moment of birth and up to six months, the volume of the cranial part of the skull almost doubles. By two years, its volume is tripled, and by the age of five it is three fourth of the volume of the entire skull. This ratio is maintained throughout life. It was during this period that the cranial fossae significantly deepened, and the occipital part of the head begins to protrude. In addition, the membranous tissue of the cranial vault and the cartilaginous tissue in the occipital bone are modified and gradually disappear. The first (initial stage) formation of sutures of the skeleton of the head occurs. This period is extremely important, since the suture of the skull is intended not just to bond the bones of the head to each other, but, more importantly, is the place of their growth in width.
Skull suture classification
The seams are subdivided in their form into the following:
- toothed;
- scaly;
- flat.
The toothed suture of the skull is formed by two bonesurfaces, when there are protrusions on one, and on the other - notches that fill these protrusions. This type of seams is the most durable. At imposing of two edges of the next located bones the scaly seam of a skull is formed. All seams are filled with connective tissue, giving strength and mobility to such compounds. And the third type of seams is flat. The flat seam of the skull is formed by the contact of slightly wavy or completely flat bone surfaces. With the help of this type of sutures, the bones of the facial skull are joined together, and their name depends on the intertwining bone formations.
Second period of change
Over the next five years, head bones growmuch slower. A visually more noticeable change occurs in the growth and shape of the facial part of the skull (orbits, nasal cavity, and upper jaw). The springings that were closed during the neonatal period completely disappear, and the seams are filled with a connective tissue.
Third period
Данный период совпадает с половым созреванием human and lasts for ten years (from 14-15 years of age to 25 years). The final growth of the skull and the entire axial skeleton occurs. During this period of life (unlike the previous two), there is a more intensive growth of the facial skull, rather than the brain. The suture of the skull, as an anatomical formation, becomes more durable, and the period of its ossification begins, which lasts until old age. Increases the base of the skull in all directions, and not just in width. The furrows, protrusions, bumps and air-bearing sinuses are finally formed.
The fourth period
From 25 years to 45 there is no change in the development of the bones of the head. During this period, the suture of the skull ossified. In very rare cases, stitches can persist throughout life.
Fifth period
This stage lasts from the period of fusion of seams and toold age itself. To a greater extent, not anatomical changes, but structural ones. Visually changes the facial skull due to tooth loss and atrophy of the alveolar processes. With age, the thickness of the spongy substance and the compact plate decreases, and the skull becomes lighter. Due to bone resorption and changes in its mineral composition, bones become more fragile, crack and break.
Conclusion
The human skull is the so-called skeleton of the head. This anatomical structure is extremely important not only to protect the brain and sensory organs. It forms our appearance (face).
The seam of the skull, being a structural-functional unit, plays an important role in connecting the bones of the skull to each other. In children, the seams have greater elasticity, and with age they ossify.
The stage of development of the bones of the skull has ageframework. Thus, the neonatal period, when the springs remain (membranous stage), with the maturing of a person enters the cartilage stage, and then into the bone one.
By the time of birth, the formation andthe skull itself. There are five stages of its development. So, from the moment of birth to school age (6-7 years), the skull grows predominantly in height, the next five to seven years are a period of relative rest, and with the onset of puberty and up to the age of 25, predominantly its facial parts change.
