Gamete Transport Flashcards
what is happening to sperm in the epididymis? broadly
acquisition of fertilizing ability and motility
describe sperm in the epididymis (3)
- no protein synthetic ability
- addition or loss of plasma membrane proteins and lipids
- redistribution of proteins and lipids within sperm
what is added to sperm in the accessory sex glands?
decapacitation factor!
describe decapacitation factor (2) structure and function
- protein, glycolipid and/or lipid
2. stabilizes plasma membrane
what animals have semen with high sperm concentration? where do they deposit sperm?
cattle and sheep; deposit in the vagina
what animals have high volumes of semen and long copulation and where do they deposit?
horses, pigs, and dogs; deposit in the uterus (horses and pigs) and cervix (dogs)
list and describe the 5 steps in the sequence of events after sperm deposition in the female
- immediate transport: retrograde loss and phagocytosis
- cervix: privileged pathway, removal of nonmotile/abnormal sperm
- capacitation: removal of decapacitation factor initiated
- oviduct: capacitation complete by isthmus
- fertilization: at AIJ
list and describe the 2 mechanisms of sperm loss from the female tract
- retrograde flow: flow backwards out of repro tract
2. phagocytosis by neutrophils: cleanse dead cells out of uterus
with AI, where is the most effective spot to deposit sperm for insemination?
the uterine horns
list the 3 evolutionary strategies for dealing with retrograde flow of semen
- coagulation of semen or a plug
- concentrated semen: think ruminants
- semen deposited in uterus
describe the specific evolutionary strategy for dealing with sperm loss in pigs and horses
larger volume, gel fraction forms a pseudo-plug
what commonly happens to mares after breeding or insemination? how is it treated?
endometritis: an inflammatory reaction to sperm that is usually treated with uterine lavage followed by oxytocin to induce uterine contractions to flush out bad stuff
how long does it take most sperm to get to the uterine horns from the cervix in cows?
6-24 hours
where do sperm dock while they wait for the chemical signal that an oocyte is on its way from the oviduct?
on cells in the uterus and isthmus
how long does it take docked sperm to get to the ampulla after the chemical signal from the approaching oocyte?
1-2 hours
what is the first barrier to sperm?
the cervix
what do the annular rings of the cervix contain?
crypts that secrete mucus
what are the 2 different types of cervical mucus based on viscosity?
- sulfomucins
2. sialomucins
how do sulfomucins play a role in the privileged pathway?
it is very viscous, so nonmotile sperm get trapped in the thick sulfomucin and get washed out later
how do sialomucins play a role in the privileged pathway?
it is much less viscous, thinner, and secreted further into the crypts; the good motile sperm get into the crypts and can swim through the thinner mucus
what part of the privileged pathway takes place in the uterus?
phagocytosis
how do sperm avoid phagocytosis in the uterus?
they dock to avoid being eaten by immune cells
what part of the privileged pathway takes place at the uterotubal junction?
selection of the most motile/nomal morphology sperm
describe the 3 locations and mechanisms of the privileged pathway
- cervix: viscous and not-viscous mucus
- uterus: phagocytosis
- uterotubal junction: select the best
