Vulva

Question 1

Female reproductive tract includes the:

Answer 1

Is one continuous tube from vagina to ovaries.
From outside in:
- External genitalia (vulva)
- Vestibule & vagina
- Cervix
- Uterus (with 2 uterine horns)
- Oviducts
- Ovaries

Question 2

Common tissue layers (in vagina, cervix, uterus, oviducts)

Answer 2

• Serous (outer)
• 2x smooth muscle layers
• Submucosa with blood vessels
• Mucosa (i.e. functional epithelium)
  Can be variation between species.

Inner lumen allows for passage of secretions (mucus), gametes (sperm/oocytes) and fetus(es)

Question 3

Broad Ligament

Answer 3

Female tract is retroperitoneal (behind peritoneum) – as it develops in fetus, it ‘pushes’ into the peritoneum & forms a supporting ligament, the broad ligament (suspends entire female tract from dorsal body wall).

This also forms a pouch between rectum & female tract (rectogenital/rectovaginal pouch)

Broad ligament broken up into different regions, depending

Question 4

Other ligaments

Answer 4

Contained within broad ligament are supporting ligaments:
- Ovarian ligament (proper ligament of ovary)  ties ovary to uterus for support
- Suspensory ligament of ovary  connect ovary to pelvic sidewall (blood/lymph supply). Note: not where oocytes go… they go through oviduct
- Round ligament of the uterus  travels through inguinal canal, tying uterus to labia
- Uterosacral ligament  connects cervix to sacrum

Question 5

Major Blood Supply

Answer 5

Three Main arteries supply female tract (contained within broad ligament):
1. Ovarian artery (from aorta)  contained in suspensory lig. in ovary
2. Uterine artery (form umbilical artery)
3. Vaginal artery (from iliac artery)
Both ovarian and vaginal artery have branches that supply uterus.

Exception = carnivore
- Don’t have specific uterine artery, uterus only supplied with blood from branches of ovarian and vaginal arteries
All species = venous drainage follows path of arterial supply.

The uterine artery can be palpated to detect pregnancy (feeling for pulsation – fremitus)

Question 6

The uterine vein & ovarian artery

Answer 6

Ovarian artery is wrapped around uterine vein
- Allows for counter-current exchange of chemical messengers (e.g. hormones) between uterus & ovary – regulated physiological processes
Very imp. In ruminant & sow

Question 7

Female external genitalia

Answer 7

Consists of vulva, which consists of 2 labia (major & minor) which meet at dorsal and ventral commissures
- Ventral commissure houses clitoris (erectile issue, highly sensitive), within clitoral fossa.
- Clitoris becomes erect when receptive to mating
Space between vulva & anus is the peritoneum (cutaneous bridge)
- Can be torn during birth

Question 8

Response to hormones

Answer 8

Vulva becomes red, swollen in response to hormone E2 in receptive females

Question 9

Protection from pathogens

Answer 9

Smooth muscle in labia ensure continued close apposition – important to prevent pathogens entering female reproductive tract
- Note: large vulves can be prone to skin cancer

Left = normal perineal conformation.
Right = sunken anus, gaping vulva

Question 10

Species differences (cow, ewe, mare)

Answer 10

-Cow, ewe, mare = similar
- Ewe = small vulva
- Cow = prominent ventral commissure
- Peritoneum relatively small in all species

Question 11

Species differences (cow, ewe, mare)
Species Differences (bitch, queen)

Answer 11

• Botch = long peritoneum compared to other species
• Vulva not pronounced in cats