Growth of the Skull

Question 1

What are the advantages for a neonate of having a comparatively flexible skull?

Answer 1

• 1 During childbirth it allows for* Plates to overlap to fit out the birth canal
• 2 During infancy it* Allows space for brain to grow
• 3 In the event of accidents such as falls* Less likely to break, more bouncy

Question 2

What type of ossification occurs in:

Flat bones of the vault of the skull?

Irregular bones of the base of the skull?

Answer 2

Flat bones of the vault of the skull? Intramembrnous ossification

Irregular bones of the base of the skull? Endochondral ossification

Question 3

• From doing your own research describe the differences seen with respect to:*
• Fonatelles*
• Dentition*
• Tympanic membrane*

Styloid and mastoid processes of the temporal bone

Answer 3

• Fonatelles-* Between flat bones of head – undergo intramembranous ossification at certain stages of development (soft spots on an infant’s head).
• Dentition-* At birth people have 20 primary teeth – erupt at about 6 months of age. By 21 all 32 permanent teeth will usually have erupted
• Tympanic membrane-* As well as Ossicles have reached adult size at Birth

Styloid and mastoid processes of the temporal bone- Styloid process arises from endochondral ossification of the cartilage from the second pharyngeal arch. Mastoid process develops after 1 year old when sternocleidomastoid muscle develops and pulls on bone

Question 4

• At what age do the following fontanelles fuse?*
• Anterior*
• Posterior*

Answer 4

• Anterior- Around 18 months*
• Posterior- 6-8 weeks old*