Gamete Transport

Question 1

what is happening to sperm in the epididymis? broadly

Answer 1

acquisition of fertilizing ability and motility

Question 2

describe sperm in the epididymis (3)

Answer 2

1. no protein synthetic ability
2. addition or loss of plasma membrane proteins and lipids
3. redistribution of proteins and lipids within sperm

Question 3

what is added to sperm in the accessory sex glands?

Answer 3

decapacitation factor!

Question 4

describe decapacitation factor (2) structure and function

Answer 4

1. protein, glycolipid and/or lipid

2. stabilizes plasma membrane

Question 5

what animals have semen with high sperm concentration? where do they deposit sperm?

Answer 5

cattle and sheep; deposit in the vagina

Question 6

what animals have high volumes of semen and long copulation and where do they deposit?

Answer 6

horses, pigs, and dogs; deposit in the uterus (horses and pigs) and cervix (dogs)

Question 7

list and describe the 5 steps in the sequence of events after sperm deposition in the female

Answer 7

1. immediate transport: retrograde loss and phagocytosis
2. cervix: privileged pathway, removal of nonmotile/abnormal sperm
3. capacitation: removal of decapacitation factor initiated
4. oviduct: capacitation complete by isthmus
5. fertilization: at AIJ

Question 8

list and describe the 2 mechanisms of sperm loss from the female tract

Answer 8

1. retrograde flow: flow backwards out of repro tract

2. phagocytosis by neutrophils: cleanse dead cells out of uterus

Question 9

with AI, where is the most effective spot to deposit sperm for insemination?

Answer 9

the uterine horns

Question 10

list the 3 evolutionary strategies for dealing with retrograde flow of semen

Answer 10

1. coagulation of semen or a plug
2. concentrated semen: think ruminants
3. semen deposited in uterus

Question 11

describe the specific evolutionary strategy for dealing with sperm loss in pigs and horses

Answer 11

larger volume, gel fraction forms a pseudo-plug

Question 12

what commonly happens to mares after breeding or insemination? how is it treated?

Answer 12

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

Question 13

how long does it take most sperm to get to the uterine horns from the cervix in cows?

Answer 13

6-24 hours

Question 14

where do sperm dock while they wait for the chemical signal that an oocyte is on its way from the oviduct?

Answer 14

on cells in the uterus and isthmus

Question 15

how long does it take docked sperm to get to the ampulla after the chemical signal from the approaching oocyte?

Answer 15

1-2 hours

Question 16

what is the first barrier to sperm?

Answer 16

the cervix

Question 17

what do the annular rings of the cervix contain?

Answer 17

crypts that secrete mucus

Question 18

what are the 2 different types of cervical mucus based on viscosity?

Answer 18

1. sulfomucins

2. sialomucins

Question 19

how do sulfomucins play a role in the privileged pathway?

Answer 19

it is very viscous, so nonmotile sperm get trapped in the thick sulfomucin and get washed out later

Question 20

how do sialomucins play a role in the privileged pathway?

Answer 20

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

Question 21

what part of the privileged pathway takes place in the uterus?

Answer 21

phagocytosis

Question 22

how do sperm avoid phagocytosis in the uterus?

Answer 22

they dock to avoid being eaten by immune cells

Question 23

what part of the privileged pathway takes place at the uterotubal junction?

Answer 23

selection of the most motile/nomal morphology sperm

Question 24

describe the 3 locations and mechanisms of the privileged pathway

Answer 24

1. cervix: viscous and not-viscous mucus
2. uterus: phagocytosis
3. uterotubal junction: select the best

Question 25

how is the oocyte transported through the oviduct?

Answer 25

muscle contractions and cilia

Question 26

where do sperm and the oocyte meet and why?

Answer 26

at the AIJ to fertilize

Question 27

where does the fertilized oocyte move after fertilization?

Answer 27

the uterotubal junction

Question 28

how long does the uterotubal junction remain closed after ovulation?

Answer 28

remains closed until day 3-5 postovulation