Repro Week 3 Flashcards
At what stage of meiosis are eggs ovulated in the bitch
Metaphase of meiosis I, completion occurs after fertilisation
Where does fertilisation occur?
First 1 third of the oviduct
What events occur at fertilisation?
Sperm and egg membrane fusion depolarises the egg membrane and causes the cortical reaction
Oocyte is activated and completion of meiosis II occurs
What is an ootid?
A cell where both pronuclei of the oocyte and the sperm are visible in the same cell
An embry has 16 cells, what is it called?
A morula
When does totipotency cease?
After the morula
What is the progression of the embryo in the mare?
Fertilised- only fertilised eggs pass into the uterus. The embryo releases prostaglandins E and F that may promote embryo migration
What occurs in a freemartin pregnancy?
Dizygotic twins of female and male, placental fusion occurs and the female is a sterile XX/XY
What does IUGR stand for?
Intra- uterine growth retardation
When does maternal recognition of pregnancy occur?
Before luteolysis
What type of placenta does the sow and mare have?
Epitheliochorial
List hormones produced by the placenta?
Progesterone, oestrogen, prolactin, placental lactogens
What is the gestation for a ewe and when is ‘placental takeover’?
5 months, 50 days
What is the gestation in the queen and when is placental takeover?
65 days, none
What species have placental takeover?
Cow, ewe, mare, humans
What is the function of oestrogens during pregnancy?
Stimulate mammary development, placental growth, increase uterine blood flow, stimulate myometrial growth, prepare for parurition
What does relaxin do?
Softens CT enabling growth of fetus, relaxes pelvis ligaments, parturition
When do endometrial cups appear in the mare?
around 40 days
Where is prolactin produced from?
Lactotrophs of anteriory pituitary gland and placenta
What is the source of progesterone in the bitch?
The CL throughout
When is PGF2alpha effective to terminate a pregnancy in the cow?
up to 150 days after which placenta takes over
How can corticosteroids terminate pregnancy?
Mimics fetal signals and induces myometrial contractions- expulsion of the fetus
What is the gestation period of a donkey?
365 days
Describe sex steroids and its relevance to inflammation?
Oestrogen is pro inflammatory and progesterone is anti inflammatory
Describe pseudopregnancy type II in the mare?
Occurs with failure between days 36 and 140 after endometrial cups have formed. There is no return to oestrus, secondary CLs will persist for normal lifespan so cannot be lysed by PGF2alpha
What is early conception factor?
Pregnancy glycoprotein produced within 48 hours of conception- an immunosuppressive, produced in horses and cows
What can be detected using a simple doppler ultrasound?
Fetal heart rate
What changes occur in the uterine artery?
Enlargment and change in blood flow- turbulent buzzing feel
What is the effect of prolonged progesterone in pregnancy on the vagina?
Thinning of the wall, few layers of epithelium
What are the best PD methods in cows?
Rectal palpation and transrectal ultrasound
What are the best PD methods in the bitch?
Transabdominal ultrasound, plasma relaxin
