What are the differences between fetal skull and adult skull?

1. Size: The fetal skull is much smaller than the adult skull. The average fetal skull is about 10 cm (4 in) in diameter, while the average adult skull is about 17 cm (7 in) in diameter.

2. Shape: The fetal skull is rounder and has a larger cranium (brain case) than the adult skull. The adult skull is more elongated and has a smaller cranium.

3. Fontanelles: The fetal skull has fontanelles, which are soft spots where the bones of the skull have not yet fused. These fontanelles allow the skull to grow and expand as the brain develops. The fontanelles close up as the child grows older, usually by the age of 2 years.

4. Sutures: The bones of the fetal skull are joined by sutures, which are fibrous joints that allow for some movement. The sutures gradually ossify (turn to bone) as the child grows older.

5. Teeth: The fetal skull does not have any teeth. The first teeth start to erupt (come in) at around 6 months of age.

6. Muscle attachments: The muscle attachments on the fetal skull are less developed than those on the adult skull. This is because the muscles of the head and neck are not fully developed in the fetus.

7. Foramina: The fetal skull has larger foramina (openings) for the passage of nerves and blood vessels. These foramina gradually decrease in size as the child grows older.

8. Weight: The fetal skull weighs about 10% of the total body weight, while the adult skull weighs about 5% of the total body weight.

These are just some of the key differences between the fetal skull and the adult skull. As the fetus grows and develops, the skull undergoes a number of changes that allow it to adapt to the demands of postnatal life.