7/21 Part Two (Overview of Structure of the Adult Skull) Flashcards
The visceral/branchial/pharyngeal arch is derived from…
neural crest
What is basically a “continuation” of the vertebrae into the head and into the brain?
chondrocranium
The jaw elements came from what?
pharyngeal arches
Flat bones have a _________ portion that is flat and sheet-like.
squamous
The malleus and incus are derived from…
the mandibular arch (1st pharyngeal arch)
What’s the name of the cartilaginous precursor in the madibular arch that ends up getting covered in dermal bone and “disappears?”
Meckel’s cartilage
The stapes is derived from…
the hyoid arch (2nd pharyngeal arch)
What part of the hyoid does the hyoid arch become?
the lesser horn of the hyoid
What part of the temporal bone does the hyoid arch form?
Styloid process of the temporal bone
Which bone comes from chondrocranium, dermatocranium, AND splanchnocranium?
temporal bone
What forms the rest of the hyoid and the laryngeal apparatus (thyroid, larynx, cricoid process)?
pharyngeal arches 3-6
When you see foramen that are for the transmission of nervous material, it is an indicator that you’re looking at….
chondrocranium
Bones of the basicranium (chondrocranium):
Which one is “full” chondrocranium?
ethmoid, sphenoid, temporal, occipital
ethmoid
Most cranial nerves escape the skull through foramen in the…
chondrocranium
The wing portions of the sphenoid are from…
splanchnocranium
The body and base of the sphenoid are from…
chondrocranium
The petrous portion is a part of what bone?
temporal
What is the most dense bone in the body?
Petrous portion
Dermal “roofing” bones:
Nasals
Frontal
Parietals
What is an “exception to the rule” that nerves pass through only chondrocranium?
supraorbital and infraorbital foramen
Dermal facial bones:
Maxilla
Zygomatic
Lacrimal
Dermal palatal bones:
Maxilla
Palatine
Vomer
Sphenoid (parts of it)
Bones of splanchnocranium:
Temporal styloid process
Middle ear ossicles
Are the mandible and maxilla bones dermal?
They started from branchial arches and were splanchnocranium but they were COVERED UP and REPLACED by dermal bone.
So they are technically NOT splanchnocranium.
