Craniofacial Skeleton Development

Question 1

what are the two bone types?

Answer 1

1-endochondral (cartilaginous precursor)

2-intramembranous (derived from mesenchyme)

Question 2

What are the three cell types of bone?

Answer 2

1-osteoblasts (deposit)
2-Osteocytes (embeded)
3-Osteoclasts (resorb)

Question 3

What is primary displacement?

Answer 3

movement of a bone due to its own growth (i.e. humerus)

Question 4

What is secondary displacement?

Answer 4

movement of a bone due to growth of other bones (i.e. fingers)

Question 5

Simulataneous deposition and resorption on peri and endosteal surfaces is referred to as?

Answer 5

remodeling

Question 6

Movement of a bone towards the deposition surface is called?

Answer 6

drift

Question 7

Where matrix is layed down or resorbed is called?

Answer 7

growth field

Question 8

A field of significant growth of a bone such as the mandibular condyle is called?

Answer 8

growth site

Question 9

Special growth sites, controlling overall bone growth such as the epiphyseal plate of long bones is called?

Answer 9

Growth center

Question 10

The neurocranium surrounds the brain and is made up of two regions, what are they?

Answer 10

1-Desmocranium (intramembranous bone more recently evolved)

2-Chondrocranium (endochondral bone anciently evolved as the cradle for the brain)

Question 11

Pharyngeal arch mesenchyme gives rise to which skull division?

Answer 11

Viscerocranium (intramenbranous)

Question 12

Strong genetic determination with minimal environmental influences is characteristic of what region of the skull?

Answer 12

Chondrocranium

Question 13

Weak genetic determination with more environmental influence is characteristic of which skull regions?

Answer 13

Desmocranium and Viscerocranium

Question 14

Neural crest gives rise to pia mater and arachnoid mater. Which layer of the desmocranium are these?

Answer 14

Inner layer (endomeninx)

Question 15

Neural crest and paraxial mesoderm give rise to dura mater and calvaria/bone. Which layer of the desmocranium are these?

Answer 15

Outer layer (ectomeninx)

Question 16

An unossified suture between 2 or more skull bones is called?

Answer 16

Fontanelle

Question 17

Mesenchymal gaps between bones of the calvaria are called?

Answer 17

Sutures (tension exerted by expanding brain cause growth at sutural edges)

Question 18

Diarthroses are movable joints. Synarthroses are immovable however, what four major types are there?

Answer 18

1-Syndesmosis (fibrous)
2-Synchondrosis (cartilagenous)
3-Synostosis (bony)
4-Gomphosis (fibrous teeth junction)

Question 19

A failure of the neural tube to close around week 4 is called what?

Answer 19

Anencephaly (results in loss of telencephalon)

Question 20

A herniation of brain tissue through persistent dura is called what?

Answer 20

Meningoencephalocele

Question 21

Premature fusion of the cranial vault sutures results in a variety of calvarian deformities called?

Answer 21

Craniosynostosis

Question 22

The optic capsule gives rise to what chondrocranium bone?

Answer 22

lesser wing of sphenoid bone

Question 23

The Prechordal cartilage gives rise to what chondrocranium bone?

Answer 23

ethmoid bone

Question 24

The Hypophyseal cartilage gives rise to what chondrocranium bone?

Answer 24

Body of sphenoid (sella turcica)

Question 25

The parachondral cartilage gives rise to what chondrocranium bone?

Answer 25

base of the occipital bone

Question 26

The otic capsule gives rise to what chondrocranium bone?

Answer 26

petrous portion of temporal bone

Question 27

As the chondrocranium grows, what two things does it push down and forward?

Answer 27

Maxilla and Viscerocranium

Question 28

A defect affecting 1 side of the face causing the maxilla and mandible to be smaller on one side is called?

Answer 28

hemifacial microsomia

Question 29

Meckels cartilage serves as a template for the intramembranous ossification of mesenchyme leading to a?

Answer 29

mandible