The vulva

The vulva marks the external opening of the urogeni­tal tract. It Consistsof two parts:

1. The Iabiae - two vertical lips joined dorsa I Iy and ventrally: the vertical slit between them is known as lhe vulval cleft. They are Iiormiilly held dosed to prevent the entry of infection. During proestrus and oestrus in the bitch, the Iabiae enlarge, but this is not seen in lhe oeslrous cycle of lhe queen.

2. The clitoris - a knob-like Slruclure of Ciivernous erectile Iissue lying in Iheclitoral fossa jusl inside the ventral angle of the vulval deft. Il is the equivalent of the male penis.