Skull

Question 1

Name the 4 main cranial bones

Answer 1

Occipital (1)
Parietal (2)
Temporal (2)
Frontal (1)

Question 2

Name the 4 main facial bones

Answer 2

Nasal (2)
Zygomatic (2)
Maxilla (1)
Mandible (1)

Question 3

Describe the eye development in the 4th - 10th week

Answer 3

Optic placode forms, moves anteriorly, and then to the front of the face

Question 4

Describe the ear development in the 4th - 10th week

Answer 4

3 auricular hillocks form from Pharyngeal Arch 1, and 3 form from Arch 2
Auricular Hillocks and External Auditory Meatus migrate to Otic Placode
Hillocks and meatus join to form the ear

Question 5

Describe the nasal development in the 5th -10th week

Answer 5

Nasal Placode forms the lateral nasal process & Medial nasal process
Medial migration of frontonasal process, Lateral nasal & Maxillary join form Nasolacrimal/Nasooptic groove
Medial process forms Philtrum, medial Maxilla, Primary Palate, medial nose

Question 6

Describe the lip development around the 7th - 10th week

Answer 6

Medial & Fronto Nasal process form the Philtrum

Medial and Maxillary join to form upper lip

Question 7

Name the two components that make up the skull

Answer 7

Neurocranium and Viscerocranium

Question 8

What is the broad definition of the neurocranium?

Answer 8

Bones that encase the brain

Question 9

What is the broad definition of the viscerocranium

Answer 9

Facial bones

Question 10

What are the two type of neurocranium?

Answer 10

Membranous

Cartilaginous

Question 11

Name the bones that are derived from the mesoderm in the neurocranium

Answer 11

Parietal, Temporal (Petrosal area), Occipital

Question 12

What type of cells carry with them the genetic code for development? Are these cells found in the Neurocranium or Viscerocranium?

Answer 12

Neural Crest Cells

Found in both

Question 13

True or False
The Viscerocranium contains such bones as the Facial Bones, Mandible, Maxilla, Zygoma, Vomer, Palatine, Lacrimal, Nasal, Conchae

Answer 13

True

Question 14

True or False
The bones derived from the mesoderm in the neurocranium contains such bones as the Temporal (squamosal), Sphenoid, Ethmoid, Frontal bones

Answer 14

False

These are the bones originating from neural crest cells

Question 15

True or False

The Viscerocranium contains only bone originating from neural crest cells

Answer 15

True

Note: The Neurocranium has both mesoderm and neural crest

Question 16

What are the types of ossification?

Answer 16

Intramembranous

Endochondral

Question 17

Which type of ossification relies on cartilage formation?

Answer 17

Endochondral

Question 18

Describe intramembranous ossification

Answer 18

Mesenchymal cells aggregate and proliferate.
Mesenchymal cells differentiate into Osteoblasts and secrete osteoid at multiple centers of ossification.
Osteoid is mineralized.

Question 19

Meckel’s cartilage is an example of which type of ossification?

Answer 19

Intramembranous

Question 20

What bones are formed by intramembranous ossification?

Answer 20

Flat bones of face and skull, mandible, clavicle

Question 21

Describe endochondral ossification

Answer 21

A hyaline cartilage model is used as a template during the generation of long and short bones
Mesenchymal osteoblasts for 2 ossification centers
Osteoid deposited in place of cartilage model

Question 22

Endochondral bone growth depends on the presence of ________.
This growth begins in the second trimester and continues into ___________

Answer 22

Epiphyseal cartilage

Early adulthood

Question 23

What is the purpose of sutures and fontanelles?

Answer 23

To provide flexibility/compression through the birth canal and to allow for rapid brain development

Question 24

What is Cranioschisis?

Answer 24

Cranial vault fails to form

Question 25

What is Craniosynostosis?

Answer 25

Premature closure of one or more cranial sutures

Question 26

What are the 4 examples of craniosynostosis?

Answer 26

Scaphocephaly (long front to occipit)
Brachycephaly (short front to occipit)
Plagiocephaly (unilateral flattening)
Clover Leaf Skull (most sutures closed)

Question 27

FGF’s and their receptors are involved in _______

Answer 27

Bone formation (especially cranial bones)