Uterus

Question 1

Uterus

Answer 1

Uterus lies between cervix & oviducts, and is organ of pregnancy
Roles include:
- Sperm transport, prostaglandin production, supporting pre-implantation embryo development, maternal side of placenta, expulsion of fetus/placenta at birth

Question 2

Uterine structure

Answer 2

The bicornuate uterus consists of central body and two horns – horn development is species dependent
Uteri with horns have an internal and external bifurcation (split)

Humans/primates = no horns, referred to as simplex uterus

Question 3

Internal uterine structures

Answer 3

In ruminants (ewe, cow), the internal surface of uterus (the endometrium) has small, non-glandular protrusion called caruncles

The sow and mare instead have endometrial folds

Both caruncles & endometrial folds are point of attachment for placenta.

Caruncles grow in size during pregnancy – an important clue for rectal palpation

Question 4

Uterus - cow

Answer 4

Question 5

Uterus – sheep

Answer 5

Question 6

Uterus - horse

Answer 6

Question 7

Uterus – pig (sow)

Answer 7

Question 8

Uterus – dog (bitch)

Answer 8

Question 9

Uterine – Cat (queen)

Answer 9

Question 10

Uterine tissue layers

Answer 10

Perimetrium
- Outer (serosal) layer, continuous with peritoneum
- External to serosal layer is mesentry of uterus (part of broad ligament)
Myometrium
- Muscular layer
- Outer longitudinal & inner circular
Endometrium (functional tissue)
- Mucosa & submucosa layers
- Secretory & functional tissue

Question 11

Myometrium

Answer 11

Middle layer of stratum vasculare contains large blood vessels
Contraction of myometrium has 2 effects
- Increased motility (movement of fluid down into cervix from uterus) – wavelike contraction
- Creation of uterine tone (rigidity – can be assessed via rectal palpation) – sustained partial contraction

Uterine tone & motility are highly influenced by reproductive hormones
- i.e. during pregnancy need low tone
- i.e. contraction of myometrium move foetus into vagina during birth

Question 12

Endometrium (functional layer)

Answer 12

Mucosal epithelium covers endometrial surface and forms spiralled uterine glands in the submucosa.

Glands secrete histotroph, a fluid to support embryo development. Gland activity changes under hormonal control
- i.e. endometrium can look different depending stage of cycle

Submucosa contains glands, blood vessels & connective tissue

Unlike humans/apes, the endometrium is not shed during female cycle in most species
- instead see more or less development of endometrial glands (but no bleeding)

Question 13

Endometrium Histo

Answer 13

Question 14

Uterine biopsy as clinical tool

Answer 14

To diagnose endometritis (look for glandular fibrosis or look for signs of inflammation)