Block IX - Reproductive

Question 1

What gene is responsible for regression of Mullerian ducts during sex differentiation in males?

Answer 1

The sry gene

Question 2

When does capacitation occur normally?

Answer 2

Upon exposure to the fluid environment of the female reproductive tract

Question 3

What is the pharmacological mechanism of currently available medication for treatment of ED?

Answer 3

Inhibiting the action of phosphodiesterase type 5

Question 4

What is the target of LH secreted by anterior pituitary?

Answer 4

Leydig cells

Question 5

What enzyme catalyzes the reaction in which testosterone is converted into dihydrotestosterone?

Answer 5

5-alpha reductase

Question 6

How many haploid oocytes and polar bodies are formed upon the completion of meiosis in women?

Answer 6

One haploid oocyte and 2 polar bodies

Question 7

In each menstrual cycle a cohort of follicles will be stimulated to develop but usually only one follicle will ovulate. Why does this follicle become dominant?

Answer 7

It is the first follicle in this cycle to convert androgens secreted by theca cells to estrogens, which have a negative feedback on gonadotropins

Question 8

What is the proper sequence of events in the menstrual cycle?

Answer 8

Estrogen peak, LH peak, first polar body, ovulation

Question 9

What determines the length of time between from ovulation to menses in a non-pregnant cycle?

Answer 9

The life span of the corpus luteum

Question 10

Which hormonal changes take place during pregnancy?

Answer 10

hCGpeaks around 70 days then declines, progesterone and estradiol increase

Question 11

What will happen if the Sertoli blood barrier in the testis is damaged?

Answer 11

There most likely will be an immune reaction and sperm antibodies will form which may interfere with sperm function

Question 12

What is the function of Wolffian duct?

Answer 12

In the developing fetus, the continued presence of Wolffian ducts will lead to male sexual development

Question 13

What does the first meiotic division result in during spermatogenesis?

Answer 13

Secondary spermocytes

Question 14

What does the transport of sperm into the vas deferens depend on?

Answer 14

The pressure exerted by the Sertoli cells which are continuously secreting fluid

Question 15

What is the mechanism of erection in the penis?

Answer 15

Arteries releasing NO, which relax the arterial smooth muscle, thereby facilitating blood flow into the corpora cavernosa

Question 16

How do hormones control spermatogenesis in males?

Answer 16

Pulsatile secretion of GnRH by the hypothalamus stimulates FSH and LH release from the anterior pituitary. LH acts on Leydig cells to stimulate secretion of testosterone, while FSH acts on Sertoli cells to stimulate spermatogenesis

Question 17

What is the correct sequence of stages during oogenesis?

Answer 17

Oogonium, primary oocyte, secondary oocyte, ovum

Question 18

What is responsible for completion of the first meiotic division in the female?

Answer 18

Midcycle LH surge

Question 19

Which hormones are produced by the corpus luteum after the ovum is expelled from the follicle?

Answer 19

Estrogen, progesterone, inhibin

Question 20

Which hormone prevents the regression of the corpus luteum during the early stages of pregnancy?

Answer 20

hCG produced by the conceptus

Question 21

What is the major hormone responsible for inducing contractions during parturition?

Answer 21

Oxytocin

Question 22

Which hormone is released at the highest level at the delivery time?

Answer 22

Estrogen

Question 23

How many copies of chromosomes per cell are in primary oocytes stage?

Answer 23

2

Question 24

During the menstrual cycle (if fertilization does not occur), which day marks the transition from follicular phase to luteal phase?

Answer 24

14

Question 25

What is the function of inhibit?

Answer 25

Acts on the pituitary to inhibit the secretion of FSH

Question 26

Which hormone does the leydig cells in the testis primarily secrete?

Answer 26

Testosterone

Question 27

What is the physiological event that characterizes menopause?

Answer 27

Primary ovarian failure

Question 28

Is the ovulatory phase among the changes in the uterus during the menstrual cycle?

Answer 28

No

Question 29

What is the function of Sertoli cells in the testes?

Answer 29

Secretion of luminal fluid, providing nutrients to developing sperm cells, secretion of that anti-Muellerian hormone, secretion of androgen-binding protein, secretion of inhibin

Question 30

From where is gonadotropin releasing hormone GnRH secreted?

Answer 30

Hypothalamus

Question 31

What is the earliest hormonal indicator of pregnancy?

Answer 31

Increase in chorionic gonadotropin, hCG peaks at around day 70 then declines, progesterone and estradiol increase

Question 32

Which enzyme facilitates the reaction that converts testosterone to estrogen in the brain?

Answer 32

Aromatase

Question 33

Why is the lifespan of the corpus luteum expanded during early pregnancy?

Answer 33

The conceptus produces human chorionic gonadotropin

Question 34

Which hormone controls the milk ejection reflex?

Answer 34

Oxytocin

Question 35

Which hormone controls milk synthesis?

Answer 35

Prolactin

Question 36

What is the sequence of developmental stages during spermatogenesis?

Answer 36

Spermatogonia, primary spermatocyte, secondary spermatocyte, spermatids, spermatozoa

Question 37

Is spermiation part of the developmental stages during spermatogenesis?

Answer 37

No. Spermiation refers to the release of mature spermatozoa from the Sertoli cells