Nostrils

Nostrils

• 
• External nares supported by cartilage - Why? Cartilages -
• reinforcement of the opening of the nasal cavity for air flow (high speed) -
• prevent collapse in this area
• Nasal septum
• Dorsolateral nasal cartilage
• Ventrolarteral nasal cartilage
• Accessory Cartilage

Nostrils of Horse

• 
• Nostril opening shaped by:
• Alar cartilage - comma shaped - flat prominent dorsal plate- lamina of alar cartilage - ventro-lateral curved cornu
• Nares opened by - dilator apicalus m. - medially to cartilage & canius, lateral nasi and levatory labialis mms - lateral and ventrally
• Horse distinguished by nasal diverticulum - dorsal in nasal opening - closed when nostrils widely flared