793 bytes added ,  14:16, 17 November 2012
Line 29: Line 29:  
[[File:Cambridge Natural History Mammalia Fig 014.png|thumb|right|400px|'''Lateral View of a Canine Skull''', Cambridge Natural History Mammalia Fig 014. (C.occ - Occipital condyle; F - frontal; F.inf - infra-orbital foramen; Jg - zygomatic arch; Jm - premaxilla; L - lachrymal; M - maxilla; Maud - external auditory meatus; Md - mandible; N - nasal; P - parietal; Pal - palatine;  Pt - pterygoid; Sph - sphenoid; Sq - squamosal; Sq.occ - supraoccipital; T - tympanic. (From Wiedersheim's Comparative Anatomy.) ]]  
 
[[File:Cambridge Natural History Mammalia Fig 014.png|thumb|right|400px|'''Lateral View of a Canine Skull''', Cambridge Natural History Mammalia Fig 014. (C.occ - Occipital condyle; F - frontal; F.inf - infra-orbital foramen; Jg - zygomatic arch; Jm - premaxilla; L - lachrymal; M - maxilla; Maud - external auditory meatus; Md - mandible; N - nasal; P - parietal; Pal - palatine;  Pt - pterygoid; Sph - sphenoid; Sq - squamosal; Sq.occ - supraoccipital; T - tympanic. (From Wiedersheim's Comparative Anatomy.) ]]  
   −
The skull comprises of many individual bones that are fused together to form a strong single structure. These individual bones in adults are fused via ossification of the cartilage between bones that is found in young animals. The classification of bones within the skull is based on the traditional views of skull drawings such as the historical drawing shown on the right.  
+
The shape and size of the skull varies widely between different breeds of dog. The skull is divided into three components - the neurocranium, the dermatocranium and the viscerocranium.The skull comprises of many individual bones that are fused together to form a strong single structure. These individual bones in adults are fused via ossification of the cartilage between bones that is found in young animals. The skull protects the brain and head against injury and supports the structures of the face. The neurocranium develops from the neural crest and mesoderm and undergoes endochondral ossification. It lies ventral to the brain. The dermatocranium lies dorsal to the brain and develops from the neural crest and mesoderm. It undergoes intramembranous ossification. The viscerocranium is the pharyngeal skeleton. It is derived only from the neural crest and undergoes endochondral and intramembranous ossification. The various facial muscles attach onto the skull in different places depending on their function. The classification of bones within the skull is based on the traditional views of skull drawings such as the historical drawing shown on the right.  
 
<br />
 
<br />
 
<br />
 
<br />
6,273

edits