11. Gametogenesis

Question 1

a) What does the release of LH do? - 2
b) What does the release of FSH do? - 2
c) where does this all occur?

Answer 1

a) causes the Leydig/interstitial cell to produce testosterone
b) causes the Sertoli cells to develop sperm
c) in the testes

Question 2

Where do the Sertoli and Leydig cells reside w/in the testis?

Answer 2

the seminiferous tubules

Question 3

Where is sperm developed in the testis?

Answer 3

the lumen of the seminiferous tubules

Question 4

Which of the following are developed sperm?
a) spermatogonia
b) spermatozoa
c) sperm
d) spermatogenesis

Answer 4

b

Question 5

Which of the following are sperm stem cells?
a) spermatogonia
b) spermatozoa
c) sperm
d) spermatogenesis

Answer 5

a

Question 6

Which of the following is the development of sperm cells?
a) spermatogonia
b) spermatozoa
c) sperm
d) spermatogenesis

Answer 6

d

Question 7

a) what is spermatogonia?
b) Where in the seminiferous tubules are spermatogonia located?

Answer 7

a) stem cells of sperm
b) the basement membrane = outer most layer

Question 8

Lable the image based on the following
a) lumen of seminiferous tubule
b) basement membrane
c) spermatozoa

Answer 8

a) yellow
b) green
c) blue

Question 9

Describe the 6 step of spermatogenesis using the following terms; spermatogonia, mitosis, meiosis, primary spermatocytes, secondary spermatocytes, spermatids, spermatozoa, basement membrane, stem cell, lumen, diploid, haploid, spermiogenesis

Answer 9

1. the spermatogonia (stem cells) undergo mitosis
2. one daughter cell remains in the basement membrane as a stem cell (spermatogonia)
3. the other daughter cell acts as the primary spermatocyte
4. the primary spermatocyte undergoes the first meiotic division giving rise to 2 haploid secondary spermatocytes
5. the secondary spermatocyte undergoes the second meiotic division giving rise to 4 haploid spermatids
6. the spermatids undergo spermiogenesis resulting in the production of spermatozoa

Question 10

a) What is oligospermia also known as?
b) when does it occur?

Answer 10

a) decreased fertility
b) when you produce less than 20 million/ml sperm

Question 11

Match the following to the image
a) lumen of seminiferous tubule
b) primary spermatocytes
c) spermatids
d) wall of seminiferous tubule
e) spermatogonia
f) secondary spermatocytes
g) Sertoli cell
h) cytoplasmic droplets
i) spermatozoa

Answer 11

a) light green
b) dark green
c) dark blue
d) pink
e) purple
f) brown
g) orange
h) light blue
i) yellow

Question 12

Put the following terms in order
a) primary spermatocyte
b) spermatogonia
c) secondary spermatocytes
d) spermatids
e) spermatozoa

Answer 12

b -> a -> c -> d -> e

Question 13

What does the term “immunological infertility” mean

Answer 13

it means that the body doesn’t recognize developing sperm as ‘self’ thus the immune sys will attack it

Question 14

The body sees developing sperm as foreign and thus tries to attack it. What are the 2 measures for preventing this?

Answer 14

1. blood-testis barrier = the tight basement membrane of the seminiferous tubules
2. Sertoli cells = they produce FAS-ligand that binds to the FAS-receptors on T-cells triggering apoptosis

Question 15

ejaculated sperm has a life span of about 80h thus how is it able to be maintained in the cervix?

Answer 15

the cervical mucus helps maintain the spermatozoa

Question 16

When migrating in the genital tract spermatozoa rapidly separate from the _______ and are resuspended in the female _______

Answer 16

seminal plasma, genital fluid

Question 17

What are the 2 requirements of spermatozoa to fertilize an egg?

Answer 17

1. the spermatozoa must undergo capacitation
2. the spermatozoa must reach the egg directly

Question 18

What eliminates most spermatozoa from fertilization?

Answer 18

phagocytosis

Question 19

What happens to damaged spermatozoa?

Answer 19

they are carried back to the cervix by the ciliated cells where they are engulfed

Question 20

What is the importance of capacitation

Answer 20

the process that allows for spermatozoa to penetrate the egg membrane

Question 21

T or F - all organisms that sexually reproduce require the capacitation step for spermatozoa in order to undergo fertilization

Answer 21

F - non-mammalians do not

Question 22

Describe the following wrt Capacitation
a) epididymal
b) ejaculated
c) capacitated

Answer 22

a) the spermatozoa w/in the testis that contains proteins and carbs on its surface in order to protect the mech needed for egg penetration
b) the ejaculated spermatozoa that are coated w/ seminal plasma proteins that protect the mech needed to penetrate the egg
c) When the spermatozoa is exposed to the female tract where the surface proteins are removed exposing the mech needed to penetrate the egg

Question 23

Which of the following matches the image best
a) spermatozoa
b) ejaculated
c) capacitated
d) epididymal

Answer 23

d

Question 24

Which of the following matches the image best
a) spermatozoa
b) ejaculated
c) capacitated
d) epididymal

Answer 24

b

Question 25

Which of the following matches the image best a) spermatozoa b) ejaculated c) capacitated d) epididymal

Answer 25

c

Question 26

match the following w/ the image a) acrosomal cap b) mitochondria c) middle piece d) head e) tail f) nucleus

Answer 26

a) yellow b) orange c) light blue d) dark blue e) pink f) green

Question 27

Put the following wall of the egg that the spermatozoa must penetrate in order a) zona pellucida b) inner acrosomal membrane c) perivitelline space d) corona radiata e) plasma membrane of egg

Answer 27

d -> b -> a -> c -> e

Question 28

What is the patch of sperm plasma membrane?

Answer 28

the area where the sperm penetrates the plasma membrane of the egg

Question 29

Describe the following a) in-vitro fertilization b) artificial insemination

Answer 29

a) harvesting and fertilizing an egg in a lab then replanting it into a recipient b) harvesting the sperm and injecting it into the uterus of the recipient

Question 30

match the following to the image a) Corpus Cavernosa b) corpus spongiosa c) arteries d) veins

Answer 30

a) blue b) red c) green d) yellow

Question 31

What is the fxn of the corpus spongiosa?

Answer 31

surrounds the urethra keeping it from closing during ejaculation

Question 32

Describe the 7 steps to an erection using the following terms; nitric oxide (NO), arterioles (arteries), corpus cavernosa, vasodilate, parasympathetic nerve, blood, vascular smooth muscle cell (VSMC), GTP, guanylate cyclase (cGMP), Ca, veins

Answer 32

1. the parasympathetic nerve releases NO to VSMC 2. activates cGMP using GTP 3. cGMP closes Ca channels resulting in a decreased cytoplasmic Ca 4. the smooth muscle relaxes resulting in vasodilation (widening of BV) of arterioles 5. more blood flows into the corpus cavernosa 6. the veins contract the prevent back flow of blood 7. erection

Question 33

What is vasodilation?

Answer 33

the widening of BV due to the adjacent muscular walls relaxing

Question 34

What is the NXT that mediates an erection

Answer 34

nitric oxide

Question 35

erections don't happen forever so what causes the termination of an erection? (4 steps)

Answer 35

1. The phosphodiesterase (PDE) catalyzes the cGMP into GMP 2. influx of Ca into the cell 3. smooth muscle to contract preventing the blood flow 4. no erection

Question 36

How does Viagra promote erection? (3 steps)

Answer 36

1. inhibits phosphodiesterase (PDE) 2. cGMP continues to be produced 3. erection promoted

Question 37

Describe the Ig Nobel prize?

Answer 37

its an achievement for something that sound funny and irrelevant but then makes you think

Question 38

There was an Ig Nobel prize that uses Viagra to cure hamster jetlag. What is the significance of this?

Answer 38

it showed that cGMP levels speeds up the internal body clock in the brain temporarily. This change in the circadian rhythm has been tide to many disorders cause by changes to ones circadian rhythm