Vestibule and Vulva of Animals
The vestibule, clitoris, and vulva are integral components of the female reproductive anatomy in animals, playing roles in reproduction and sensory functions.
Vestibule
Portion of the vagina that is common to the urinary system and the reproductive system. Extends from the urethral orifice to the labia of vulva. At the floor of the vestibule are the Gartners ducts-blind sacs which are remnants of the Wolffian duct. Ventral to the urethral opening is the suburethral diverticulum in sow and cow. It is a blind pouch.
The vestibule located between the vulva and vagina from the caudal termination of the genital tract. The vestibule acts as a point of attachment for the entire genital tract to contract upon when expelling the foetus.
- Cow: Vagina in cow is 10-12.5 cm long on the ventral floor. Vestibule or Bartholins glands are two in number and opens by a single duct into the lateral wall of the vestibule.
- Mare: 8-10 ducts from each vestibular gland open through its dorso-lateral wall.
- Ewe: Similar to cow. Vestibular glands are absent.
- Sow: Vestibule is long-8.9 cm. Cul de sac is the pouch located on the either side of the cranial portion of the floor of the vestibule.
- Bitch: Vestibular glands are absent.
- Cat: Vestibular glands are Present.
Vulva
External part of the female reproductive tract. Consist of Labia majora and labia minora. The skin of the labia have numerous sebaceous and sweat glands. The labia consists of adipose tissue into which are embedded small bundles of smooth muscles which are called constrictor vulvae muscles.
Clitoris
Located in the caudal portion of the ventral commissure. Homologues to the penis 5-10 cm long. Most of it is hidden in the tissue between vulva and the ischiatic arch.
In mares clitoris is prominent and composed of erectile tissue similar to the penis. Contraction of the vestibular and vulvar sphinceter muscles elevate the clitoris and protrudes it between the vulval lips. This is called winking of clitoris.
Well supplied with sensory nerve endings. Functional significance not known. Clitoral stimulation following AI has found to increase the conception rate by advancing the LH surge by 4 hours and thereby the ovulation by 4 hours.
