Control of Pregnancy Flashcards
1
Q
How is pregnancy controlled?
A
Endocrine control
2
Q
Why is the placenta important for pregnancy control?
A
- stimulates ovarian function
- maintains pregnancy
- affects foetal growth
- aids parturition
- prepares for lactation
3
Q
What hormones are involved in controlling a pregnancy?
A
- progesterone
- maternal recognition pregnancy factors
- equine chorionic gonadotrophin
-placental lactogen
oestrogens
4
Q
Why is progesterone important for controlling pregnancy?
A
- produced by corpus luteum and placenta
- low pregnancy rate = low progesterone
-histotroph production - tightens cervix
- suppression of ovarian activity (APART FROM MARE)
- Behavioural changes
5
Q
Why is maternal recognition of pregnancy important?
A
- effect other hormones release (eg- oxytocin)
- imperative for the survival of the corpus luteum
6
Q
Why is the corpus luteum different in the mare?
A
- secondary corputus lutem formed due to increased ovarian activity they can have up to 15 (day 40-60)
7
Q
How is placental lactogen produced?
A
- cows and sheep
- produced from binucleate cells of the placenta
- production of histotroph
- modulates foetal/maternal metabolisum
-optimises energy supply to foetus
