Female comparative anatomy

Question 1

What are the different uterus types and in which species are they found?

Answer 1

1. Simplex - no uterine horns - primates
2. Bicornuate - poor to moderately developed uterine horns - mare and cow
3. Bicornuate - highly developed uterine horns - bitch, queen, sow
4. Duplex - two cervices - marsupials and rabbits

Question 2

Which structure can not be picked up in a mare during a rectal examination?

Answer 2

The cervix - due to tight dorsal attachment of mesometrium

Question 3

In which species is the CL not palpable?

Answer 3

Mare

Question 4

Which follicular cells synthesise oestrogen?

Answer 4

Granulosa cells

Question 5

Compare cow ovaries to mare ovaries

Answer 5

• Cows are smaller than a mare
• Mares are bean shaped, cows are not
• Both ovulatory follicle
• Corpus luteum only protrudes in a cow
• Cows ovulate from different places, mare only ovulate from the ovulatory fossa
• Cows have an extensive infundibulum, whilst a mares is small

Question 6

A dominant follicle will only ovulate if which hormone is at basal level?

Answer 6

Progesterone

Question 7

In a mare, what prevents ovulation through the surface of the ovary?

Answer 7

Tough tunica albuginea

Question 8

Where does ovulation occur in the mare and why is it at this point?

Answer 8

• through an ovulation fossa

- there is no tunica albuginea in this area, located in the hilus of the ovary

Question 9

How is the oocyte released into the infundibulum in the mare?

Answer 9

Because the follicle is so large 3.5-5cm, one part of the periphery of the follicle impinges on the ovulatory fossa, this area ruptures causing the oocyte to be released

Question 10

What are the 3 components of the oviduct?

Answer 10

• infundibulum
• ampulla
• isthmus

Question 11

What is the role of the infundibulum and why is it less extensive in mares compared to other species?

Answer 11

• Captures the oocyte
• Most species ovulate at random point so need extensive infundibulum to capture oocyte.
• The mare always ovulates from a single ovulation fossa so infundibulum less extensive

Question 12

What is the function of the ampulla?

Answer 12

Site of fertilisation

Question 13

What is the function of the isthmus?

Answer 13

Where sperm are stored

Question 14

Which structure forms an ovarian bursa and what is the role of this?

Answer 14

Mesosalpinx

Peritoneal sac encapsulating the ovary

Question 15

What are the 3 layers of uterine tissue?

Answer 15

Perimetrium - outside serosa
Myometrium - muscle layer
Endometrium - mucosa and submucosa

Question 16

Describe the placenta of a sow and mare

Answer 16

Diffuse placenta - endometrial folds throughout the uterus contribute to the maternal placenta

Question 17

What is distinct about the uterine tissue of cattle and sheep?

Answer 17

They have maternal caruncles

Question 18

What is the role of the cervix during pregnancy?

Answer 18

It isolates the conceptus from the external environment

Question 19

Briefly describe the cervixes of the following:

1. queen and bitch
2. cow and ewe
3. mare
4. sow

Answer 19

1. Small and smooth
2. Have distinct protrusions called cervical rings
3. Has longitudinal folds which are continuous with endometrial folds
4. Has interdigitating prominences

Question 20

What are 3 reasons you may introduce a catheter through the cervix?

Answer 20

• AI
• Embryo transfer
• Treating uterine infections

Question 21

Which tissue are the caudal vagina and vestibule derived from?

Answer 21

Ectoderm

Question 22

Which tissue is the cranial vagina and uterus derived from?

Answer 22

Mesoderm

Question 23

What are the names given to the inner and outer foetal sac?

Answer 23

inner = amnion
outer = chorioallantois

Question 24

The allantoic cavity is continuous with which part of the developing foetus?

Answer 24

Foetal bladder

Question 25

What provides interface with the dam?

Answer 25

Chorionic villi

Question 26

What are the functions of the placenta?

Answer 26

- Provides an interface for metabolic exchange between the foetus and dam - Produces hormones to maintain pregnancy - Stimulates maternal mammary gland - Produces hormones to promote foetal growth

Question 27

What is the foetal contribution to the placenta?

Answer 27

Allantochorion

Question 28

What is the functional part of the foetal placenta?

Answer 28

Chorionic villus - increase SA for exchange, protrude towards the uterine endometrium

Question 29

What type of placenta do cows and sheep have?

Answer 29

Cotyledonary placentae - button like regions of chorionic villi

Question 30

What are the 6 epitheliochorial layers in cattle, sheep, pigs and mares?

Answer 30

1. Endometrial capillary 2. Maternal basement membrane 3. Maternal endometrial epithelium 4. Fetal chorion 5. Fetal basement membrane 6. Chorionic capillary

Question 31

What are the 3 functions of the amniotic membranes and fluid?

Answer 31

- encloses foetus - hydrostatic pressure for foetus - mucoid at the end of gestation to provide lubricant for birth

Question 32

What are the 2 functions of the allantoic membranes and fluid?

Answer 32

- Early collection of urine | - Hydrostatic protection

Question 33

Which umbilical vessels make up the umbilical cord?

Answer 33

- Urachus - Two umbilical arteries - Umbilical vein (bifurcates in ruminants)

Question 34

What does the urachus connect?

Answer 34

The bladder to the allantoic cavity

Question 35

What do the following become: 1. Umbilical artery 2. Umbilical vein 3. Urachus

Answer 35

1. Round ligament of the bladder 2. The round ligament of the liver 3. The median ligament of the bladder

Question 36

What happens to the umbilical cord at birth?

Answer 36

- Amniotic membrane of cord is broken - Umbilical arteries retract back - Umbilical vein and urachus close