Reproductive System (Test 3)

Question 1

What gene is responsible for regression of Müllerian 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 medications for the treatment of erectile dysfunction, such as Viagra, Cialis and Levitra?

Answer 3

Inhibiting the action of phosphodiesterase type 5.

Question 4

What is the target cell of LH secreted by the anterior pituitary?

Answer 4

Leydig cells.

Question 5

What enzyme catalyze the reaction in which testosterone is converted into Dihydrotestosterone?

Answer 5

5α 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 two 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 thecal cells to estrogens, which have a negative feedback on gonadotropins.

Question 8

What is the proper sequence of events in a 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

hCG peaks at 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 results in during spermatogenesis?

Answer 13

Secondary spermatocytes.

Question 14

What does the transport of sperm into the vas deferens depends 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 nitric oxide which relaxes the arterial smooth muscle thereby facilitating blood flow into the corpora cavernosal.

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 make the transition from follicular phase to luteal phase?

Answer 24

14

Question 25

What is the function of inhibin?

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

Answer 28

no

Question 29

What is the function of the Sertoli cells in the testes?

Answer 29

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

Question 30

From where the gonadotropin releasing hormone (GnRH) is secreted?

Answer 30

hypothalamus

Question 31

What is the earliest hormonal indicator of pregnancy?

Answer 31

Increase in chorionic gonadotropin. hCG peaks at around 70 days 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 the milk synthesis?

Answer 35

Prolactin.

Question 36

What is the sequence of developmental stages during spermatogenesis?

Answer 36

spermatogonia - primary spermatocytes - secondary spermatocytes - 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.