test 3: skull Flashcards
skull acts as shield for:
- Brain
- Special sense organs
- Cranial parts of the respiratory and digestive systems
- Provides attachments for many head and neck muscles
•Jawless fishes (like lampreys) had/have gills with ___for support
cartilage gill bars (precursors of jaw)
the cartilage of the cranium
chondrocranium
___ become the jaws in jawed fish
first pair of gill bars
in a shark the first pair of gill bars becomes
cartilage
turns to bone in bony fish and tetrapods
the second pair of gill bars turn into ___
support for the jaw on the side of the cranium
what bones make up the brain case?
endochondral bones (start as cartilage first)
occipital, sphenoid and ethmoid
two types on bone in the skull
endochondral bones (cartilage first) -brain case: occipital, sphenoid and ethmoid
mesenchyme: dermal skull roof: roof, face and jaw
bones of the ___ form directly from mesenchyme
dermal skull roof
joints between dermal bones are called ___
sutures
joints between brain case bones are called ___
synchondroses
•When joints fuse (either kind) junction is called ___
synostosis
__ is a soft spot on the skull
fontanella
where frontal and parietal meet
2 and 7?
occipital condyle
tympanic bulla
1 and 6
- orbit/eye socket
6: Zygomatic arch “Cheek bone”•Made by: •Zygomatic process of temporal bone•Zygomatic bone
3,4,5
3. External naris •Nostril•Infraorbital canal•A bony canal that runs from orbit to face that transmits infraorbital artery and nerve•Maxillary foramen (entrance)
4: Infraorbital foramen (exit)
5: External acoustic meatus
occipital condyle articulate with the ___
1st cervical vertebrae
atlas bone
what makes up the zygomatic arch?
- Zygomatic process of temporal bone
- Zygomatic bone
Y and P?
- Mastoid process (Y)•Mastoid muscle attachment•Hyoid attachment
- Paracondylar process (P)•“Jugular process” or “Paroccipital process”•Digastricus muscle origin•Neck muscle attachment
D,H and Z
•Occipital surface (D)•
Tympanic Bulla (H)•
Occipital Condyle (Z)
where does digastricus attach?
paracondylar process
what kind of animal has a sagittal crest?
carnivore- large temporalis muscle- large bite force
what kind of animal have temporal lines?
herbivore- small temporalis- big massester (grinding_
origin of temporalis?
sagittal crest or temporal line or temporal fossa
dolichocephalic
long nose- has sagittal crest
mesaticephalic
middle sized- one sagittal crest
three structures that attach to mastoid process
- Hyoid apparatus via tympanohyoid cartilage
- Sternocephalicus pars mastoideus
- Cleidocephalicus pars mastoideus
what attaches at the paracondylar process
digastricus (jaw opening)
do horses have sagittal crest or temporal lines?
sagittal crest (weak)
and facial crest
do cows have sagittal crest or temporal lines
temporal lines and facial tuberosity
what is 2?
nasoincisive notch
1
cornual diverticulum of the frontal sinus
2
cornual process of the frontal bone
where does masseter attach in horses
zygomatic arch extended onto the facial crest
the cranial cavity is roofed by
frontal and parietal bones
the bottom of the cranial cavity is made of __
occipital and sphenoid bones