Lecture 19: Skeletal System Development II

Question 1

What is the base of the neurocranium formed from?

Answer 1

Chondrocranium

Question 2

Occipital, sphenoid, ethmoid, & parts of temporals form which neurocranium part?

Answer 2

Chondrocranium

Question 3

Occipital, parietals, frontals, & part of temporals form which neurocranium part?

Answer 3

Membranous

Question 4

What does the viscerocranium surround?

Answer 4

Oral cavity and pharynx

Question 5

What does the cartilaginous portion of the viscerocranium form?

Answer 5

Pharyngeal arch I (meckel’s cartilage)

Pharyngeal arch II (Reichert’s cartilage)

Question 6

What does the membranous portion of the viscerocranium form?

Answer 6

Temoral, zygomatic, maxillary, nasal, lacrimal, alatine, vomer, pterygoid plates, mandible, & tympanic ring

Question 7

The viscerocranium is mostly comprised of the _____ arches?

Answer 7

Branchial (pharyngeal)

Question 8

The mesenchyme that forms the viscerocranium is mostly from _____.

Answer 8

Neural crest

Question 9

How many pairs of pharyngeal arches are there?

Answer 9

6

Question 10

What are the 4 components of the pharyngeal arch?

Answer 10

Skeletal, muscles, branch of specific cranial nerve, & artery

Question 11

Basioccipital portion of chondrocranium is derived from what?

Answer 11

Parachordal cartilage and occipital sclerotome

Question 12

What is elongation of the primary ossification centers of chondrocranium due to?

Answer 12

Shh

Question 13

What are fontanelles?

Answer 13

Intersections between sutures where more than two bones meet

Question 14

If FGF-2 is present, noggin is _____ and BMP is _____. This causes bones to _____.

Answer 14

Suppressed.
Up-regulated.
Fuse.

Question 15

If FGF-2 is not present, noggin is _____ and BMP is _____. This causes bones to _____.

Answer 15

Up-regulated.
Suppressed.
Remain open

Question 16

What is craniosynostosis?

Answer 16

Premature closure of certain sutures between major membrane bones of the neurocranium