7/21 Part One (Overview of Structure of the Adult Skull) Flashcards
What are the 3 component origins of the developing skull?
Chondrocranium
Dermatocranium
Splanchnocranium
Another name for chondrocranium…
basicranium
What supports the brain from underneath?
chondrocranium/basicranium
What kind of bones make dermatocranium?
flat bones
The splanchnocranium bones were originally derived from…
pharyngeal/gill arch elements
Endochondral mode of formation means..
it has a cartilaginous precursor; it is derived from cartilage
“In endochondral formation, it means we usually see the bone is __________ in origin because of the cartilaginous precursor.”
-Noriega
mesodermal
Chondrocranium…
Mode of formation:
Germ layer origin:
Endochondral
Mesoderm
Dermatocranium…
Mode of formation:
Germ layer origin:
Dermal
Neural crest
Splanchnocranium…
Mode of formation:
Germ layer origin:
Endochondral
Neural crest
Chondrocranium and splanchnocranium both have endochondral modes of formation, but the reason splanchnocranium is derived from neural crest is…
Splanchnocranium has a cartilaginous precursor but it gets COVERED then replaced with dermal bone
Chondrocranium is homologous to…
Why?
- the rest of the axial skeleton
- it is derived from mesoderm, just like the axial skeleton (skeleton = somites = mesoderm)
What is the “extension” of your vertebrae that forms the base of your skull?
chondrocranium
Other names for pharyngeal arches:
visceral arches
branchial arches
What is the first arch?
Second arch?
1st = Mandibular arch 2nd = Hyoid arch
Eventually the hyoid branch started making a connection to the…
braincase
What bone becomes the roof of the skull? Where do they form?
Dermal
In the skin
What is the hole where the spinal cord exits to become the spinal column?
Foramen magnum
The foramen magnum is a hole for the transmission of…
nervous tissue
Basisphenoid and basioccipital bones are what kind of bones?
chondrocranium
The roof of the mouth is derived from what bone?
chondrocranium
Forming a little bit of the base that holds our brains and also forming a little bit of the walls is derived from…
Splanchnocranium
The jaw is made of what bone?
Splanchnocranium
The splanchnocranium of the jaw gets covered with what?
dermal bone
Before we evolved, what were the “remnants of the mandibular arch”?
quadrate and articular
What did the quadrate and articular become?
ear ossicles
What are the ear ossicles?
malleus
incus
stapes
Which ear ossicles are remnants of the mandibular arch?
malleus and incus
Where did the stapes come from?
the hyoid arch
