Biology
Human Skull
1-The skull supports the structures of the face and provides a protective cavity for the brain.
2- It is a bony structure, which is composed of two parts namely the cranium and the mandible.
3-The English word “skull” is probably derived from Old Norse “skalli” meaning bald.
4- The Skull forms the head in the human skeleton. It supports the structures of the face and forms a cavity for the brain.
5-The human skull is generally considered to consist of twenty-two bones—eight cranial bones and fourteen facial skeleton bones.
6-The bones of the facial skeleton are the vomer, two nasal conchae, two nasal bones, two maxilla, the mandible, two palatine bones, two zygomatic bones, and two lacrimal bones.
7-The skull also contains sinus cavities and numerous foramina. The sinuses are lined with respiratory epithelium. Their known functions are the lessening of the weight of the skull.
8-The foramina are openings in the skull. It allows the passage of the spinal cord as well as nerves and blood vessels.
9-Male skulls on average have larger, broader palates, squarer orbits, larger mastoid processes, larger sinuses, and larger occipital condyles than those of females
10-The skull is one of the least deformable structures found in nature with it needing the force of about 1 ton to reduce the diameter of the skull by 1 cm.
11-At birth, the human skull is made up of 44 separate bony elements.
12-The bones of the roof of the skull are initially separated by regions of dense connective tissue called fontanelles.
13-The skull is a complex structure; its bones are formed both by intramembranous and endochondral ossification.
14-The base of the skull is short and narrow, though the inner ear is almost adult size.
15-Some of these bones—the occipital, parietal, frontal, in the neurocranium, and the nasal, lacrimal, and vomer, in the facial skeleton are flat bones.
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