Lecture 5: Gamete Transport and Fertilization Flashcards Preview

COB Embryology > Lecture 5: Gamete Transport and Fertilization > Flashcards

Flashcards in Lecture 5: Gamete Transport and Fertilization Deck (22):
1

What is the main mechanism for transport of the egg in uterine tube?

Contractions of tubal smooth muscle

2

Which type of transport requires progesterone?

A. Slow transport in ampulla
B. Rapid transport through isthmus
C. Medium transport in ampulla

B. Rapid transport through isthmus

3

When does the egg arrive in the uterus?

3-4 days after departure

4

What mechanisms propel immotile sperm through male reproductive tract?

Passive transport via testicular fluid, muscle contraction, cilia from seminiferous tubules

5

What is the path of sperm to the point that it reaches the epididymis?

Rete testis, efferent ductules, epididymis

6

Where does sperm maturation occur and how long does it require?

Epididymis, 12 days

7

Which of the following fluid secretions provide nutrition and energy supply for sperm?

A. Prostaglandins
B. Fructose
C. Citric acid
D. Phosphatase

B. Fructose

8

The acidic pH of which of the following structures is of most concern regarding the passage of sperm?

A. Upper vagina
B. Cervix
C. Upper uterine tube
D. Isthmus

A. Upper vagina

9

What is the optimal pH for sperm motility?

6.0-6.5

10

Initial rapid transport of sperm

Spermatozoa reach uterine tubes within 5-20 minutes of ejaculation; relies on muscular movement of female tract; sperm not as capable of fertilization

11

Slow transport of sperm

Sperm may not reach oviducts for 2-4 days; involves swimming through cervical mucous and storage in cervical crypts; sperm more capable of fertilization

12

Where does fertilization typically occur?

Ampulla

13

Capacitation

Required for sperm to undergo acrosomal reaction and fertilize egg; involves removal of cholesterol and glycoproteins

14

Where does capacitation occur?

Isthmus of uterine tube

15

What enzyme found in the acrosome is responsible for penetration of the corona radiata?

Hyaluronidase

16

What protein stimulates the acrosomal reaction in mammals?

ZP3

17

Where is acrosin/zona lysin initially found and what is its purpose?

Found in acrosome, digests small hole through ZP and assists in penetration of sperm through ZP

18

Fast block to polyspermy

Rapid depolarization of egg plasmalemma that temporarily prevents polyspermy and allows time for slow block to be established

19

Slow block to polyspermy

Release of polysaccharides from the cortical granules located just under the plasmalemma of the egg, causing a swelling that increases perivitelline space

20

Phospholipase C zeta

Produced by sperm and facilitates Ca2+ release in egg, making it metabolically active

21

Pronucleus

Nuclear material of the head of spermatozoan or of the oocyte after the oocyte has been penetrated by the spermatozoan

22

Zygote

Denotes single-celled stage at which the male and female pronuclei have fused together and share a common membrane, establishing the diploid chromosome number