Changes

===Nasal Bone (os nasale)===

===Nasal Bone (os nasale)===

[[Image:Ethmoid Turbinates.jpg|thumb|right|150px|Ethmoid Turbinates (Dog) - Copyright nabrown RVC]]

[[Image:Ethmoid Turbinates.jpg|thumb|right|150px|Ethmoid Turbinates (Dog) - Copyright nabrown RVC]]

 

The nasal bone is a paired structure and forms the roof of the nasal cavity. '''Dorsal nasal conchae''' attach to the '''ethmoidal crest''' on the internal surface. A rostral suture forms the apex and between the nasal and incisive bones is the '''nasoincisive notch'''.

*Forms the roof of the nasal cavity

*Dorsal nasal conchae attach to the ethmoidal crest on the internal surface

===Lacrimal Bone (os lacrimale)===

*Rostral suture form the apex

The lacrimal bone forms part of the lateral wall of the face and orbit and is situated near the '''medial canthus'''. It articulates with the '''frontal bone, zygomatic bone''' and '''maxilla'''. It also articulates with the '''nasal bone''' in ruminants and the horse and articulates with the '''palatine bone''' in carnivores. It is composed of an orbital and facial part separated by supra- and infraorbital margins. The '''nasolacrimal duct''' is present by the margin of the orbital surface. The '''ventral oblique muscle''' attaches caudal to the margin of the orbital surface. The nasal surface forms the boundaries of the '''maxillary and frontal sinuses'''.

*Between the nasal and incisive bones is the nasoincisive notch

 

'''Lacrimal Bone (os lacrimale)'''

===Zygomatic Bone (os zygomaticum)===

 

The zygomatic bone is lateral and ventral to the lacrimal bone and forms the orbit and zygomatic arch. The supraorbital margin is formed by the zygomatic process of the temporal bone and the frontal process of the zygomatic bone. The facial crest is present on lateral surface.

*Forms part of the lateral wall of the face and orbit

*Situated near the medial canthus

*It articulates with the frontal bone, zygomatic bone and maxilla

**Also articulates with the nasal bone in ruminants and the horse

**Also articulates with the palatine bone in carnivores

*Composed of an orbital and facial part separated by supra- and infraorbital margins

*The nasolacrimal duct is present by the margin of the orbital surface

*Ventral oblique muscle attaches caudal to the margin of the orbital surface

*Nasal surface forms the boundaries of the maxillary and frontal sinuses

 

'''Zygomatic Bone (os zygomaticum)'''

 

*Lateral and ventral to the lacrimal bone

*Forms the orbit and zygomatic arch

*Supraorbital margin formed by the zygomatic process of the temporal bone and the frontal process of the zygomatic bone

*Facial crest present on lateral surface

[[Image:Cow skull lateral view.jpg|thumb|right|150px|Cow skull (incisive bone, nasal bone, maxilla, nasoincisive notch labelled) - Copyright nabrown RVC]]

[[Image:Cow skull lateral view.jpg|thumb|right|150px|Cow skull (incisive bone, nasal bone, maxilla, nasoincisive notch labelled) - Copyright nabrown RVC]]

 

'''Incisive Bone (os incisivium)'''

 

===Incisive Bone (os incisivium)===

The incisive bone is a paired structure composed of body, nasal, palatine and alveolar parts. It joins with the maxilla to form the '''interalveolar margin'''. It also forms the rostral part of the facial section of the skull, the roof of the '''[[Hard Palate|hard palate]]''' and the opening to the nasal cavity. The alveolar process forms conical sockets for the incisor teeth.

*Composed of body, nasal, palatine and alveolar parts

*Joins with the maxilla to form the interalveolar margin

*Forms the rostral part of the facial section of the skull, the roof of the [[Hard Palate|hard palate]] and the opening to the nasal cavity

===Palatine Bone (os palatinum)===

*The alveolar process form conical sockets for the incisor teeth

The palatine bone is a paired structure between the maxilla, sphenoid and pterygoid bones. It is composed of a horizontal plate (forms part of the [[Hard Palate|hard palate]]), perpendicular plate (forms the dorsal and lateral walls of the nasopharyngeal meatus) and the choanae. The '''nasal crest''' present on the horizontal plate. The '''palatine sinus''' is present on horizontal plate.

 

'''Palatine Bone (os palatinum)'''

 

*Between the maxilla, sphenoid and pterygoid bones

*Composed of a horizontal plate (forms part of the [[Hard Palate|hard palate]]), perpendicular plate (forms the dorsal and lateral walls of the nasopharyngeal meatus) and the choanae

*Nasal crest present on the horizontal plate

*Palatine sinus present on horizontal plate

[[Image:Palatine Bone.jpg|thumb|right|150px|Palatine Bone and Maxilla (Pig) - Copyright nabrown RVC]]

[[Image:Palatine Bone.jpg|thumb|right|150px|Palatine Bone and Maxilla (Pig) - Copyright nabrown RVC]]

 

'''Vomer'''

 

===Vomer===

The vomer is unpaired and extends from the choanae of the palatine bone to the floor of the nasal cavity. It attaches to the median nuchal crest and has a '''septal sulcus''' which surrounds nasal cavity.

*Extends from the choanae of the palatine bone to the floor of the nasal cavity

*Attaches to the median nuchal crest

*Septal sulcus formed which surrounds nasal cavity

===Pterygoid Bone (os pterygoideum)===

 

The pterygoid bone is a paired structure bordered by the '''palatine''' and '''sphenoid bones'''. It forms the dorsal and lateral walls of the '''nasopharyngeal cavity'''. The '''pterygoid hamulus''' is formed by the pterygoid bone.

'''Pterygoid Bone (os pterygoideum)'''

 

*Bordered by the palatine and sphenoid bones

*Forms dorsal and lateral walls of the nasopharyngeal cavity

 

'''Maxilla'''

'''Maxilla'''

[[Image:Horse Maxilla.jpg|thumb|right|150px|Horse Maxilla - Copyright RVC]]

[[Image:Horse Maxilla.jpg|thumb|right|150px|Horse Maxilla - Copyright RVC]]