Neuroanatomy 2: The skull Flashcards
What is this bone called (2 names)? What are its main features?
Incisive bone/Premaxilla
- Forms apex of skull
- Houses the incisors
- Forms part of nasal aperature
What is this bone called? What features does it have?
• Maxilla
– Largest bone of facial region
– Houses canines, premolars and molars
– Forms nasal and oral cavities
What is this bone called? What features does it have?
Nasal bone
– Forms roof of nasal cavity
– External surface is convex
What is this bone called? What features does it have?
zygomatic/malar (mammals) / jugal
Consists of two parts
- Body
- Articulates with Maxilla
- Temporal process
- From Temporal bone
What bone is this? What features does it have?
Lacrimal
- Rostral wall of orbit
- Lacrimal fossa
- Leads to lacrimal duct
- Small in dog
What bone is this? What features does it have?
Ethmoid
- Deep in Skull
- Ethmoidal Turbinates = Ethmoidal conchae
- Cribriform Plate (caudal aspect) - olfactory function
What bone is this? What are some of its features?
Palatine bone
- Forms hard palate
- Horizontal lamina
- Forms lateral wall of skull
- Perpendicular lamina
- Forms part of the orbit
What bone is this? What are some of its features?
Pterygoid
– Forms part of nasal cavity
– Forms the caudal part of the nasopharynx
What bone is this? What are some of its features?
Vomer
– Lies in midline of skull
– unpaired
What bone is this? What are some of its features?
frontal
– Forms roof and sides of cranium
– Two bones that meet midline and usually fuse
– Contains frontal sinus
– Bears sagittal crest (some species)
What bone is this? What are some of the features it has?
Parietal
– Forms roof and sides of cranium
– Unites at sagittal suture
– Forms sagittal crest (in some species)
What bone is this? What are some of its features?
Temporal
– Forms lower part of lateral wall
• Squamosal part
• Petrosal part (around ear, inside skull)
• Temporal part (temporal process; TMJ)
• Mastoid process
What is this bone and what are some of its features?
Occipital
- Comprised of four bones
- Bears Nuchal crest
- Bears foramen magnum
What are the four parts of the occipital bone?
Fusion of four neonatal bones
- squamous part (supraoccipital)
- lateral parts (left and right exoccipital)
- Occipital Condyles
- Articular surface of atlanto‐occipital joint
- Occipital Condyles
- basilar part (basioccipital)
What is this bone and what are some of its features?
Sphenoid complex:
– Median body with two wings (or alae)
– Houses the optic chiasma
• Basisphenoid Bone
• Presphenoid Bone
What is this bone and what are some of its features?
Mandible/dentary bone
– United at intermandibular suture
• Can be fused or not –species dependent
– Body (or corpus)
– Ramus
– Masseteric fossa
– Coronoid process
– Condyloid process
– Angular process
What are sutures?
Fibrous joints, unique to the skull, where independent centres of ossification meet
What structures form from the splanchnocranium during skull development?
– Visceral skeleton (yellow)
• Develops within pharyngeal arches
(jaws and gills)
• Middle ear bones in mammals
What structures form from the chondrocranium during skull development?
– Neurocranium or primary braincase (blue)
• Formed in cartilage
• Protects brain and special sense organs
• Replaced by bone in all vertebrates (except elasmobranchs)
What structures form from the dermatocranium during skull development?
– Dermal skeleton (pink)
• Intramembranous origin in mammal
- e.g. parietal, frontal, palatine, macilla, dentary
