Changes

== Species Differences  ==

== Species Differences  ==

=== Canine  ===

=== Canine  ===

Dogs have different skull lengths depending on breed. '''mesocephalic''' dogs have average conformation whilst '''dolichocephalic''' dogs have longer skull lengths and '''brachycephalic''' dogs have shorter skull lengths. The two sides of the mandible do not fuse allowing some movement in the canine jaw. The '''external sagittal crest''' arises from '''nuchal crest'''. The wings of the basisphenoid bones form the '''oval foramen, spinous foramen''' and '''carotid canal'''. Dogs have no '''foramen lacernum''' and the styloid process absent. In canines the dorsal margin of orbit is formed by the orbital ligament, the orbit is incomplete. <br> <br> [[Image:Lion skull.jpg|thumb|right|150px]]

[[Image:Pug skull.jpg|thumb|right|150px|Pug skull.jpg]] Dogs have different skull lengths depending on breed. '''mesocephalic''' dogs have average conformation whilst '''dolichocephalic''' dogs have longer skull lengths and '''brachycephalic''' dogs have shorter skull lengths. The two sides of the mandible do not fuse allowing some movement in the canine jaw. The '''external sagittal crest''' arises from '''nuchal crest'''. The wings of the basisphenoid bones form the '''oval foramen, spinous foramen''' and '''carotid canal'''. Dogs have no '''foramen lacernum''' and the styloid process absent. In canines the dorsal margin of orbit is formed by the orbital ligament, the orbit is incomplete. <br> <br> <br>

=== Feline  ===

=== Feline  ===

The mandible appears globular in shape and the large orbits have complete bony margins. There are also large '''tympanic bulla''' which can be palpated. The two parts of the mandible do not fuse allowing some movement. Cats have a '''weak external sagittal crest''' arising from the '''nuchal crest'''. The wings of the basisphenoid bones form the '''oval foramen, spinous foramen''' and '''carotid canal'''. Cats have no '''foramen lacernum''' and the styloid process is absent. The dorsal margin of orbit is formed by the orbital ligament which is ossified. The '''interpareital bone''' does not fuse entirely in the adult. <br> <br> [[Image:Horse Skull.jpg|thumb|right|150px]]

[[Image:Lion skull.jpg|thumb|right|150px|Lion skull.jpg]] The mandible appears globular in shape and the large orbits have complete bony margins. There are also large '''tympanic bulla''' which can be palpated. The two parts of the mandible do not fuse allowing some movement. Cats have a '''weak external sagittal crest''' arising from the '''nuchal crest'''. The wings of the basisphenoid bones form the '''oval foramen, spinous foramen''' and '''carotid canal'''. Cats have no '''foramen lacernum''' and the styloid process is absent. The dorsal margin of orbit is formed by the orbital ligament which is ossified. The '''interpareital bone''' does not fuse entirely in the adult. <br> <br>  

=== Equine  ===

=== Equine  ===

Horses have a '''weak external sagittal crest''' arising from the '''nuchal crest'''. They also have an '''internal sagittal crest''' on the '''internal surface of the pareital bone'''. The orbit is placed more laterally with a complete bony rim and a strong '''zygomatic arch''' continues on to form the '''facial crest'''. There is a '''deep nasoincisive notch''' and a prominent '''hamular process'''. Horses have a very large mandible with a '''vascular notch''' and a high ramus. The wings of the basisphenoid bones form the '''oval foramen, spinous notch''' and '''carotid notch'''. Horses have a '''foramen lacernum'''. The zygomatic process articulate with the zygomatic process of the temporal bone. Horses have '''three rows of ethmoturbinates present'''. <br> <br> [[Image:Sheep skull.jpg|thumb|right|150px]]

[[Image:Horse Skull.jpg|thumb|right|150px|Horse Skull.jpg]] Horses have a '''weak external sagittal crest''' arising from the '''nuchal crest'''. They also have an '''internal sagittal crest''' on the '''internal surface of the pareital bone'''. The orbit is placed more laterally with a complete bony rim and a strong '''zygomatic arch''' continues on to form the '''facial crest'''. There is a '''deep nasoincisive notch''' and a prominent '''hamular process'''. Horses have a very large mandible with a '''vascular notch''' and a high ramus. The wings of the basisphenoid bones form the '''oval foramen, spinous notch''' and '''carotid notch'''. Horses have a '''foramen lacernum'''. The zygomatic process articulate with the zygomatic process of the temporal bone. Horses have '''three rows of ethmoturbinates present'''. <br> <br> <br> <br> <br>

=== Ruminant  ===

=== Ruminant  ===

In ruminants the skull is short and wide with a '''[[Horn - Anatomy & Physiology|cornual]]''' process on frontal bone. The nuchal crest is reduced to a '''nuchal line''', although there is a prominent '''temporal line'''. Ruminants have an elevated orbital ring which is complete but have no facial crest. There are prominent '''tympanic bullae''' and a '''nasoincisive notch''' present. The wings of the basisphenoid bones form the '''oval foramen'''. Ruminants have no '''foramen lacernum'''. The petrosal and tympanic parts of the temporal bone are fused to the squamous part. The zygomatic process articulates with the frontal process of the zygomatic bone. <br> <br> [[Image:Pig skull.jpg|thumb|right|150px]]

[[Image:Sheep skull.jpg|thumb|right|150px|Sheep skull.jpg]] In ruminants the skull is short and wide with a '''[[Horn - Anatomy & Physiology|cornual]]''' process on frontal bone. The nuchal crest is reduced to a '''nuchal line''', although there is a prominent '''temporal line'''. Ruminants have an elevated orbital ring which is complete but have no facial crest. There are prominent '''tympanic bullae''' and a '''nasoincisive notch''' present. The wings of the basisphenoid bones form the '''oval foramen'''. Ruminants have no '''foramen lacernum'''. The petrosal and tympanic parts of the temporal bone are fused to the squamous part. The zygomatic process articulates with the frontal process of the zygomatic bone. <br> <br> <br> <br>

=== Porcine  ===

=== Porcine  ===

Pigs have a thick nucal crest and an '''internal sagittal crest''' on the internal surface of the pareital bone. They have a prominent '''temporal line''' and their orbit is incomplete and small. There is a strong and deep zygomatic arch, large tympanic bullae and a high caudal part of the skull. The styloid process absent. <br> <br> [[Image:Bird skull.jpg|thumb|right|150px]]

[[Image:Pig skull.jpg|thumb|right|150px|Pig skull.jpg]] Pigs have a thick nucal crest and an '''internal sagittal crest''' on the internal surface of the pareital bone. They have a prominent '''temporal line''' and their orbit is incomplete and small. There is a strong and deep zygomatic arch, large tympanic bullae and a high caudal part of the skull. The styloid process absent. <br> <br> <br> <br>

=== Avian  ===

=== Avian  ===

Birds have '''pneumatised skull bones''' which connect to airways in the head rather than the air sacs. They have large orbits and their skull plates are separated by spongy bone. A '''single occipital condyle''' articulates with the '''atlas''' allowing more rotation of the head. In parrots, the nasal bone and frontal bone are joined by a flexible cartliage structure allowing greater jaw opening which is called the craniofacial hinge. This allows kinesis to occur. Birds have thin '''jugal arches''' (equivalent to zygomatic arch) and the middle ear contains only the columella (equivalent to the stapes). <br> <br>  

[[Image:Bird skull.jpg|thumb|right|150px|Bird skull.jpg]] Birds have '''pneumatised skull bones''' which connect to airways in the head rather than the air sacs. They have large orbits and their skull plates are separated by spongy bone. A '''single occipital condyle''' articulates with the '''atlas''' allowing more rotation of the head. In parrots, the nasal bone and frontal bone are joined by a flexible cartliage structure allowing greater jaw opening which is called the craniofacial hinge. This allows kinesis to occur. Birds have thin '''jugal arches''' (equivalent to zygomatic arch) and the middle ear contains only the columella (equivalent to the stapes). <br> <br>

== Test yourself with our Skull and Facial Muscles Flashcards  ==

== Test yourself with our Skull and Facial Muscles Flashcards  ==