7/21 Part One (Overview of Structure of the Adult Skull)

Question 1

What are the 3 component origins of the developing skull?

Answer 1

Chondrocranium
Dermatocranium
Splanchnocranium

Question 2

Another name for chondrocranium…

Answer 2

basicranium

Question 3

What supports the brain from underneath?

Answer 3

chondrocranium/basicranium

Question 4

What kind of bones make dermatocranium?

Answer 4

flat bones

Question 5

The splanchnocranium bones were originally derived from…

Answer 5

pharyngeal/gill arch elements

Question 6

Endochondral mode of formation means..

Answer 6

it has a cartilaginous precursor; it is derived from cartilage

Question 7

“In endochondral formation, it means we usually see the bone is __________ in origin because of the cartilaginous precursor.”

-Noriega

Answer 7

mesodermal

Question 8

Chondrocranium…
Mode of formation:
Germ layer origin:

Answer 8

Endochondral

Mesoderm

Question 9

Dermatocranium…
Mode of formation:
Germ layer origin:

Answer 9

Dermal

Neural crest

Question 10

Splanchnocranium…
Mode of formation:
Germ layer origin:

Answer 10

Endochondral

Neural crest

Question 11

Chondrocranium and splanchnocranium both have endochondral modes of formation, but the reason splanchnocranium is derived from neural crest is…

Answer 11

Splanchnocranium has a cartilaginous precursor but it gets COVERED then replaced with dermal bone

Question 12

Chondrocranium is homologous to…

Why?

Answer 12

• the rest of the axial skeleton

- it is derived from mesoderm, just like the axial skeleton (skeleton = somites = mesoderm)

Question 13

What is the “extension” of your vertebrae that forms the base of your skull?

Answer 13

chondrocranium

Question 14

Other names for pharyngeal arches:

Answer 14

visceral arches

branchial arches

Question 15

What is the first arch?

Second arch?

Answer 15

1st = Mandibular arch
2nd = Hyoid arch

Question 16

Eventually the hyoid branch started making a connection to the…

Answer 16

braincase

Question 17

What bone becomes the roof of the skull? Where do they form?

Answer 17

Dermal

In the skin

Question 18

What is the hole where the spinal cord exits to become the spinal column?

Answer 18

Foramen magnum

Question 19

The foramen magnum is a hole for the transmission of…

Answer 19

nervous tissue

Question 20

Basisphenoid and basioccipital bones are what kind of bones?

Answer 20

chondrocranium

Question 21

The roof of the mouth is derived from what bone?

Answer 21

chondrocranium

Question 22

Forming a little bit of the base that holds our brains and also forming a little bit of the walls is derived from…

Answer 22

Splanchnocranium

Question 23

The jaw is made of what bone?

Answer 23

Splanchnocranium

Question 24

The splanchnocranium of the jaw gets covered with what?

Answer 24

dermal bone

Question 25

Before we evolved, what were the “remnants of the mandibular arch”?

Answer 25

quadrate and articular

Question 26

What did the quadrate and articular become?

Answer 26

ear ossicles

Question 27

What are the ear ossicles?

Answer 27

malleus
incus
stapes

Question 28

Which ear ossicles are remnants of the mandibular arch?

Answer 28

malleus and incus

Question 29

Where did the stapes come from?

Answer 29

the hyoid arch