Mammalian Final! Flashcards
Regions of skull (2)
Neurocranium
Facial skeleton
Embryological origins of skull (2)
Nerual crest
Mesoderm
Ossification types of skull (2)
Endochondral ossification
Intramembranous ossification
Phylogenetic origins of skull (3)
Chondrocranium
Splanchnocranium
Dermatocranium
Regions of occipital bone (3)
Supraoccipital
Ex-occipitals
Basioccipital
Function of occipital series
Protects otic capsule
Regions of sphenoid bone (5)
Basisphenoid Presphenoid Orbitosphenoid (optic capsule) Alisphenoid (greater wing) Pterygoid process
Function of sphenoid series
Protects optic cavities
Regions of ethmoid bone (3)
Turbinates
Perpendicular plate
Cribiform plate
Cribiform plate function
Brain rests on it
Olfactory nerve travels through cribiform foramina
Meckel’s cartilage
what is it derived from, what does it contribute to later
Derived from splanchnocranium
Contributes to mandible in later mammals
Splanchnocranium contribution
1st pair of cartilaginous rods becomes jaws
Forms hyoid bone and part of larynx
Contributes to ossicles
Phylogenetic skull region with jaw articulation (uniquely to mammals) ((where did it shift from?))
Dermatocranium
Shifted from splanchnocranium; quadrate-articular joint
Bones contributing to facial vault in dermatocranium (3)
Frontal
Parietal
Interparietal
Bones contributing to facial skeleton in dermatocranium (3)
Maxilla
Nasal
Incisive (premaxilla)
Primary palate comes from which phylogenetic region of skull?
Chondrocranium
Secondary palate comes from which phylogenetic region of skull? Which bones are responsible?
Dermatocranium
Maxilla fusing together
Bones contributing to lateral walls of nasal cavity (4)
Pterygoids
Palatine
Maxilla
Premaxilla
Bones contributing to floor (palate) of nasal cavity (3)
Palatine
Maxilla
Premaxilla
Bones contributing to median wall of nasal cavity (2)
Vomer
Perpendicular plate
Bones contributing to orbital skeleton (5)
Lacrimal Zygomatic Palatine Frontal Sphenoid
Regions of temporal bone (3)
Pterous portion
Squamous portion
Ossicles and styloid
Developmental origins of teeth and what each origin contributes (2)
Ectoderm; ridge forms dental lamina
Neural crest; condenses to form dental papillae
Tooth cell populations (2)
Ameloblasts
Odontoblasts
Tooth materials (4)
Dentine
Enamel
Cementum
Pulp
Location of odontoblasts; what they produce
Core of tooth
Produce dentine
Location of ameloblasts; what they produce
Outside of tooth
Produce enamel
Enamel structure, composition, cellularity
Highly crystalline
Made of hydroxyapetite
Acellular (ameloblasts die after its production)
Hardest structure in vertebrates
Dentine structure, composition, cellularity
Tubular
Made of hydroxyapetite with some collagen
Cytoplasmic extensions of odontoblasts responsible for tubes
Pulp contribution and origin
Contains blood vessels and nerves
Derived from neural crest
Cementum function, composition, and cellularity
Holds tooth in place
Composition similar to bone
Acellular near crown, but cellular at apex
Bradydont teeth (shape and animals they’re found in)
Short
Found in not-herbivores
Hypsodont teeth (shape, animals they’re found in, and distinguishing feature)
High-crowning
Found in herbivores
Crown covered by cementum; wears down with age
Thecodont teeth (distinguishing feature, what they allow for)
Teeth with well-defined sockets
Alveolar bones create sockets
Distinguishing feature of mammals
Allow for precise occlusion; crushing and shearing
Tricodont teeth (what are they, where are they found)
Teeth with 3 cusps
Found in early, non-heterodont animals
Tribosphenic teeth (what are they, what do they confer)
Triangular teeth with 3 cusps on different planes
Giver staggered occlusion, teeth mesh together well
Feature of upper tribosphenic teeth (1)
3 cusps referred to as trigon
Features of lower tribosphenic teeth (2)
3 cusps referred to as trigonid
Additional shelf jutting out is talonid
Where are rootless teeth found? what does rootless mean?
Found in rodents
Pulp cavity remains open throughout life
Diphydonts (what they are, what it’s good for)
Animals who get 2 sets of teeth
True molars aren’t replaced
Defining feature of mammals
Adaptation for growing cranium
Heterdonts
Specialization between teeth (i.e. molars AND incisors AND canines)
Only found in larger mammals
Labial
side of teeth facing lips
Lingual
side of teeth facing oral cavity
Mesial
towards face
Distal
towards back of mouth
Dental formula order
canines:incisors:molars:pre-molars
Edentate
no teeth
Action of molars in carnivores
shearing
Structure for filter-feeding in whales
bayleen
Action of molars in herbivores
grinding
Only mastication muscle found in non-mammals
Adductor mandibulae
Bones composing jaw in earlier mammals
Dentary
Angular
Surangular
(all dermatocranium)
Symphyseal surface
site of fusion between dentary bones
Nerve innervating jaw (and sensory, motor, or mixed?)
V3 Mandibular branch of trigeminal nerve
mixed
Name of sensory part of V3 mandibular nerve (and where does it travel?)
inferior alveolar
travels inside body of mandible
Site of Novocaine injection
mandibular foramen
Alternative name for TMJ
dentary-squamosal joint
TMJ type of joint
synovial
What separates two articular surfaces of TMJ
articular disc
What jaw feature limits protrusion and retraction
rostral and caudal tubercules
Types of jaw movement (4)
protrusion
retraction
elevation
depression
Progression of jaw joint types
from quadrate-articular to temporomandibular
Role of quadrate and articular bones in current mammals
middle ear bones
Herbivory jaw adaptations (2)
very large masseter
TMJ lies well above occlusal plane
Carnivory jaw adaptations (2)
large temporalis to generate shearing force
TMJ lies close to occlusal plane
Optic nerve II (sensory, motor, or both)
sensory
Occulomotor nerve III (sensory, motor, or both? where does it enter skull from? what does it do?
motor
passes through superior orbital fissure
somatic innervation: to all the extrinsic eye muscles except lateral rectus and superior oblique)
visceral innervation: to ciliary body and sphincter pupillae
Trochlear nerve IV (sensory, motor or both? and to what?)
motor
to superior oblique
Abducens nerve VI (sensory, motor or both? and to what?)
motor
to lateral rectus
