Repro week 4 Flashcards
What are the 3 stages of parturition?
- initiation of myometrial contractions
2 expulsion of foetus - expulsion of foetal membranes
What is the main hormone that sets off parturition process?
Foetal cortisol which reduces progesterone levels and stimulates uterine prostaglandins
What initiates oxytocin release?
Increasing pressure on the cervix activates pressure sensitive neurons, sending info to the hypothalamus
What is the function of PGF2alpha, PGE2 and PGI2 in parturition?
PGF2alpha is responsible for contraction, PGE2 is important in cervical softening and PGI2 is responsible for relaxation
Affect of beta2 adrenergic agonst?
Inhibits contractions and causes relaxation
Where is relaxin produced in the ruminants and sow?
the corpus luteum
What is the first definitive sign of 2nd stage parturition?
Onset of abdominal contractions
Describe fergusons reflex?
Abdominal and uterine contractions force fetus against cervix. A neuro-hormonal reflex leads to release of oxytocin causing myometrial contractions
Which membrane is the first to rupture?
Allantochorion
How long should 2nd stage of parturition last in the mare?
30 minutes
What is meant by presentation?
Relation between longitudinal axis of fetus and maternal birth canal
What is the normal disposition of the foetus?
Cranial, longitudinal presentation, dorsal position, extended posture
What are the steps in embryo transfer
Selection of male and female donors, superovulation of donor female
Insemination of donor female with semen
Recovery of viable embryos
Synchronisation of recipient with donor female
Transfer of embryo into recipient
What is the difference between totipotent and pluripotent?
Totipotent cells are capable of forming the entire organism
Pluripotent are able to form bodys cell lineages, including germ cells
What is somatic nuclear transfer
re-construction of an embryo by the transfer of genetic material from a donor cell to a recipient egg from which genetic material has been removed
