01-15: Transport of Gametes

Question 1

What is the status of the graafian follicle at pre-ovulation?

Answer 1

mature graafian follicle

Question 2

What is the status of the oocyte at pre-ovulation?

Answer 2

oocyte arrested in Diplotene of Prophase I

Question 3

What causes expansion of the follicle at pre-ovulation?

Answer 3

FSH and LH

Question 4

What is the status of the oocytes progress through Meiosis I and II at pre-ovulation?

Answer 4

• Meiosis I = complete

- Arrested at Metaphase II

Question 5

What is the status of the stigma at pre-ovulation?

Answer 5

formation of stigma

Question 6

What happens pre-ovulation?

Answer 6

1- Mature graafian follicle
2- Oocyte arrested in Diplotene of Prophase I
3- Expansion of follicle by FSH and LH
4- Completion of meiosis I
5- Arrest at metaphase II
6- Formation of stigma

Question 7

What happens at ovulation (Day 14)?

Answer 7

1- LH surge from anterior pituitary
2- Increased blood flow to follicle wall
3- Thickening of outer layers of follicle
4- Release of fluid/other compounds from BV
5- Local production of matrix metalloproteinases
6- Secretion of HA from cumulus cells
7- Inflammatory action (rupture of follicle wall)

Question 8

What are the fluids and other components that are released at ovulation from BV?

Answer 8

• Edema
• Prostaglandins
• Histamine
• Vasopressin
• Plasminogen activator

Question 9

What do the matrix metalloproteinases do?

Answer 9

degrade extracellular matrix

Question 10

When does the inflammatory action causing rupture of follicle wall occur during ovulation?

Answer 10

about 24 hours after the LH surge

Question 11

What is ovulated?

Answer 11

• Ovum at Metaphase II
• ZP
• Corona radiata
• Expanded cumulus oophorus

Question 12

What happens when the fimbriae of the uterine tube move closer to the ovary and sweeps across the surface?

Answer 12

• Ciliation of tube epithelial cells INCREASES

- Activity of tubal smooth muscle cells INCREASES

Question 13

What transports the egg through the uterine tube?

Answer 13

contractions of smooth muscle

Question 14

How long does it take the egg to transport through the ampulla?

Answer 14

72 hours (slow transport)

Question 15

How long does it take the egg to transport through the isthmus?

Answer 15

8 hours (rapid transport)

Question 16

What does the rapid transport of the egg through the isthmus require?

Answer 16

progesterone

Question 17

How many days does it take the egg to arrive at the uterus?

Answer 17

3-4 days

Question 18

How many days for:

• Implantation
• Blastocyst
• Morula
• Cleavage

Answer 18

• Implantation = 6 days
• Blastocyst = 4 days
• Morula = 3 days
• Cleavage = 1 day

Question 19

After spermiogenesis, what 3 kinds of transport does the sperm use?

Answer 19

• passive transport (via testicular fluid)
• smooth muscle contractions
• seminiferous tubule cilia

Question 20

Where does the sperm travel through after spermiogenesis?

Answer 20

• Through Rete testes (network of tubules)
• Through Efferent ductules (Efferent pathway)
• To Head of epididymis (highly coiled)

Question 21

What are the steps of sperm transport in the male?

Answer 21

1- Passive transport to Epididymis via testicular fluid

2- Maturation in Epididymis (2 weeks)

3- Rapid transit through Ductus Deferens

4- Addition of fluid from Seminal Vesicle

5- Addition of Prostatic fluid

Question 22

What are the steps of sperm transport in the female?

Answer 22

1- Sperm deposited in upper vagina (increase pH)

2- Cervix

3- Uterus

4- Uterine tubes

5- Up uterine tube by swimming and contractions of the tube

6- Small number of sperm near egg at a given time

Question 23

What happens during the sperm maturation in the head of the epididymis (12 days)?

Answer 23

Sperm head plasma membrane changes in glycoproteins (incapacitation)

Question 24

When are sperm capable of fertilization?

Answer 24

by the time they reach the tail of the epididymis

Question 25

What are the sperm ejaculated through?

Answer 25

Ductus deferens

Question 26

What are the additional fluid secretions that are ejaculated?

Answer 26

- Fructose - Prostaglandins - Citric acid - Zn - Mg - Phosphatase

Question 27

What secretes Fructose and Prostaglandins?

Answer 27

Seminal vesicles

Question 28

What secretes Citric acid, Zn, Mg, and Phosphatase?

Answer 28

Prostate

Question 29

What buffers the acidity of vaginal fluids in the upper vagina?

Answer 29

seminal fluid

Question 30

What is the pH change in the upper vagina due to sperm transport?

Answer 30

4.3 >> 7.2

Question 31

What is the pH in the cervix?

Answer 31

6.0-6.5 Optimal for sperm motility

Question 32

How does the mucous block in the cervical canal change during mid cycle?

Answer 32

- composition and viscosity of mucous changes | - thick >> thin and watery

Question 33

Some spermatozoa reach the uterine tubes within _________ minutes following ejaculation

Answer 33

5-20 minutes Initial rapid transport These sperm = NOT as capable of fertilizing egg

Question 34

What does the initial rapid transport of sperm rely most on?

Answer 34

muscular movements of the female tract

Question 35

What does slow sperm transport involve?

Answer 35

sperm swimming through cervical mucous

Question 36

How fast does sperm move through the cervical canal during slow transport?

Answer 36

2-3 mm per hour

Question 37

Where is sperm stored during slow transport?

Answer 37

in cervical crypts

Question 38

How long can it take for the sperm to reach the oviducts during slow transport?

Answer 38

2-4 days

Question 39

What is the isthmus the site of?

Answer 39

capacitation

Question 40

What happens to the sperm after release following capacitation?

Answer 40

sperm move up the oviduct by: - Swimming movements - Peristaltic contractions

Question 41

Where does fertilization occur?

Answer 41

ampulla

Question 42

What happens to the membrana granulosa during the formation of the corpus luteum?

Answer 42

it breaks down

Question 43

Where do BV grow during the formation of the corpus luteum?

Answer 43

into the cavity of the ruptured follicle

Question 44

What causes the growth of BV into the cavity of the ruptured follicle?

Answer 44

External thecal cell angiogenic factor release

Question 45

What causes the leutinization of granulosa cells?

Answer 45

granulosa lutein cells = secrete increasing amounts of progesterone and some estrogen

Question 46

How does the corpus luteum breakdown in the absence of fertilization late in the menstrual cycle?

Answer 46

- Apoptosis | - Uterine luteolytic factors

Question 47

How is the corpus albicans formed from granulosa lutein?

Answer 47

the granulosa lutein cells are replaced with collagenous scar tissue

Question 48

What is the fate of the corpus luteum if pregnancy occurs?

Answer 48

- it is maintained by HCG from future placental tissues - granulosa lutein cells are replaced by theca lutein cells - it remains functional until after the 1st trimester

Question 49

What is capacitation required for?

Answer 49

sperm to undergo acrosomal reaction

Question 50

Where does capacitation occur?

Answer 50

in the isthmus in the uterine tube

Question 51

What does capacitation require?

Answer 51

binding of sperm to tubal epithelium

Question 52

What are the steps of capacitation?

Answer 52

1- Cholesterol removed from sperm surface 2- Glycoproteins from epididymis are removed 3- Period of hyperactivity 4- Release of sperm in small numbers

Question 53

Removal of cholesterol from the sperm surface inhibits _____________

Answer 53

premature capacitation