What structural adaptions are apparent in the fetal skull Ex

What structural adaptions are apparent in the fetal skull? Explain how these are adaptive.

Solution

In comparison to other parts of skeleton, the skull is large at the time of birth. the facial portion is small which is about 1/8th of bulk of cranium in comparison to 1/2 in adult. Prominently found portions are frontal and parietal lobes. The skull bones are completely not ossified. The unossified regions between these bones are termed as fontanelles. the largest fontanelle is the anterior fontanelle which is placed at the saggital, coronal and frontal sutures. The posterior fontanelle isfat the found at the junction of the sagittal and lambdoidal sutures, which is traingular in shape. The lateral fontanelles matches with the sphenoidal and mastoid angles of the parietal bones which are small, irregular in shape. At the time of birth the smallness of face is mainly due to the rudimentary condition of the maxillae and mandible, the non-eruption of the teeth, and the small size of the maxillary air sinuses and nasal cavities. During the period from birth to the seventh year, growth of skull occurs rapidly and the foramen magnum and petrous parts of the temporal bones have reached their full size and the orbital cavities are only a little smaller than those of the adult. During the second period of activity slow growth occurs till puberty. The growth activity in the second period results in an increase in all directions, which is specifically marked in the frontal and facial regions, which is concerned with development of the air sinuses.