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Skull and Facial Muscles - Anatomy & Physiology (view source)
Revision as of 12:41, 30 July 2008
, 12:41, 30 July 2008no edit summary
===Sphenoid Bone===
===Sphenoid Bone===
*
*Forms the base of the neurocranium
*Composed of a body and wings
*Bones separated by cartilage which ossifies with age
*Presphenoid (os praespenoidale)
**Rostrally
**Rostral caudal fossa
**Hollow body with sphenoid sinuses located inside
**Sphenoid rostrum present
**Optic chiasma
**Optic Canal
*Basisphenoid (os basispenoidalis)
**Caudally
**Median cranial fossa
**The wings oppose the temporal bone, maxilla, orbit and the brain
**Wings form the oval foramen and other foramen (see species differences) carotid notch, oval foramen and spinous notch (in the horse)
**Pterygoid processes present
**Alar canal (rostral and caudal alar foramen)
===Temporal Bone===
===Temporal Bone===
*Hypoglossal Canal
*Hypoglossal Canal
**Between paracondylar and condylar processes on lateral part of occipital bone
**Between paracondylar and condylar processes on lateral part of occipital bone
*Optic Chiasma
**Runs in transverse depression behind sphenoid rostrum on presphenoid bone
*Optic Canal
**Ends from optic chiasma over wings of the presphenoid bones
*Oval Foramen
**Caudal wing of the basisphenoid bones
*Alar Canal
**Rostral border of the basisphenoid bone at the base of the pterygoid processes
==Species Differences==
==Species Differences==
*External sagittal crest arises from nuchal crest
*External sagittal crest arises from nuchal crest
*Wings of the basisphenoid bones form the oval foramen, spinous foramen and carotid canal
*No foramen lacernum
[[Image:Lion skull.jpg|thumb|right|150px|Feline skull (Lion) - Copyright RVC]]
[[Image:Lion skull.jpg|thumb|right|150px|Feline skull (Lion) - Copyright RVC]]
===Feline===
===Feline===
*Weak external sagittal crest arises from nuchal crest
*Weak external sagittal crest arises from nuchal crest
*Wings of the basisphenoid bones form the oval foramen, spinous foramen and carotid canal
*No foramen lacernum
[[Image:Horse Skeleton.jpg|thumb|right|150px|Horse Skeleton - Copyright Nottingham]]
[[Image:Horse Skeleton.jpg|thumb|right|150px|Horse Skeleton - Copyright Nottingham]]
**Vascular notch on mandible
**Vascular notch on mandible
**High ramus
**High ramus
*Wings of the basisphenoid bones form the oval foramen, spinous notch and carotid notch
*Foramen lacernum present
[[Image:Sheep skull.jpg|thumb|right|150px|Sheep skull - Copyright RVC]]
[[Image:Sheep skull.jpg|thumb|right|150px|Sheep skull - Copyright RVC]]
===Ruminant===
===Ruminant===
*Nasoincisive notch present
*Nasoincisive notch present
*Wings of the basisphenoid bones form the oval foramen
*No foramen lacernum
[[Image:Pig skull.jpg|thumb|right|150px|Pig skull showing tusks - Copyright RVC]]
[[Image:Pig skull.jpg|thumb|right|150px|Pig skull showing tusks - Copyright RVC]]
===Porcine===
===Porcine===