Gamete Transport Flashcards
how are sperm and oocytes released by trout
directly into the water
how long does motility last for trout sperm
30 seconds
what is the name of the hole trout sperm must find
micropyle
rapid transport phase characteristics
-occurs withing minutes
-peristaltic contractions induced by copulation
-most sperm become damaged or immotile
what is the purpose of the rapid transport phase
get as many sperm through the cervix as quickly as possible
slow transport phase characteristics
-sperm imbed in cilia to undergo capacitation
-fertilizing sperm to AIJ
cervical phase characteristics
-removal of nonmotile sperm and abnormalities
-privileged pathways
-billions of sperm
roles of cervix
-receptive at estrus(mucus)
-reservoir cervical crypts
-protein from vagina(phagocytosis)
-energy
-filtration of dead/defective sperm
where is capacitation initiated
uterus
capacitation average length? for sheep? pigs?
average: 1-7 hrs
sheep: 1.5 hrs
pig: 3-6 hrs
what is capacitation
-biochemical change
-removal of sperm outer plasma membrane(helmet)
-necessary for acrosomal reaction to occur
uterine phase characteristics
-millions of sperm
-movement through contractions
-capacitation
stimulators for contractions in uterine phase
-PGF 2a(from semen)
-oxytocin(from posterior pituitary)
utero-tubal junction phase characteristics
-limits number of sperm reaching oviduct(smaller tube)
-acts as 2nd filter
-sperm reservoir
-sperm imbed into epithelium to await ovulation
where is capacitation completed
oviduct
where does hyperactivation occur
oviduct
oviduct phase characteristics
-hundreds to thousands of sperm
-transported by contractions and fluid ‘currents’
-sperm reservoir in isthmus
sperm oviduct binding
-sperm trapped in isthmus region by carbohydrate-mediated binding
-sperm disassociate from epithelium to complete capacitation and hyperactivity
what sperm-specific ion channel allows for hyperactivation
CatSper
how does CatSper work
progesterone binds to its receptor opening CatSper which allows calcium to enter and H+ to exit causing pH to increase
mechanisms for oocyte movement through reproductive tract
-cilia
-fluid currents
-peristaltic contractions
T/F the oocyte can survive longer in the reproductive tract than sperm
FALSE
