VAN 221: Veterinary Splanchnology and Applied Anatomy (1+1)

VULVA (COW)

• The vulva or urogenital sinus is the terminal part of the uro-genital tract and is continuous in front with the vagina and opens externally at the vulvar cleft below the anus
• It is about 10 to 12 cm long and is related above to the rectum and anus and below to the floor of the pelvis and laterally to the sacrosciatic ligaments
• The vulvar cleft is a vertical slit 10 to 12 cm high, margined by two prominent-lips the labia vulvae
• They are thick, wrinkled and unite above and below to form the dorsal and ventral commissures respectively
• Both commissures are acute; the dorsal one is below the anus while the ventral one is pointed and lies behind and below the level of the ischial arch and has a number of long hairs on it
• The clitoris is composed of erectile tissue and is the homologue of the penis
• When the lips are drawn apart a fossa is noticed at the ventral commissure called the fossa clitoridis, which lodges the pointed free end of the clitoris called glans clitoridis
• Below and in continuation with the glans is the corpus clitoridis 10 to 12 cm long, which is formed by the union of the two crura clitoridis, which are attached to the ischial symphysis by suspensory ligaments
• The external urethral orifice is in the form of a longitudinal slit about 10 to 12 cm from the ventral commissure on the ventral wall
• It is covered by a fold of mucous membrane, the free end of which is directed backwards. Beneath this, is a blind pouch the suburethral diverticulum about 3.5 cm long
• The mucous membrane of the vulva is pink or yellowish red in colour. At the floor a pair of large and some small vestibular glands are present