Q: Which equation best represents the negative feedback loop involving testosterone in the HPG axis?

$$GnRH \rightarrow FSH/LH \rightarrow Testosterone \rightarrow \text{Inhibition of GnRH/FSH/LH}$$

Question 1

Which hormone is primarily responsible for stimulating the release of androgen-binding protein (ABP) from Nurse cells in the male reproductive system?

Accepted Answer

Follicle-stimulating hormone (FSH)

Question 2

A male patient presents with low sperm count and decreased testosterone levels. Laboratory tests reveal normal GnRH but low FSH and LH. Which gland is most likely malfunctioning?

Accepted Answer

Anterior pituitary

Question 3

During the male sexual response, which molecule is directly responsible for causing the dilation of penile blood vessels, leading to erection?

Accepted Answer

Nitric oxide (NO)

Question 4

Which of the following best describes the negative feedback mechanism involving testosterone in the HPG axis?

Accepted Answer

High testosterone inhibits the release of GnRH and gonadotropins

Question 5

A patient is prescribed Viagra for erectile dysfunction. What is the physiological basis for this treatment?

Accepted Answer

It enhances and prolongs the effects of nitric oxide

Question 6

Which layer of the uterine wall is shed during menstruation?

Accepted Answer

Stratum functionalis

Question 7

During the ovarian cycle, what triggers the surge of luteinizing hormone (LH) that leads to ovulation?

Accepted Answer

A critical high concentration of estrogen exerting positive feedback

Question 8

If fertilization does not occur, what is the fate of the corpus luteum and how does this affect the uterine cycle?

Accepted Answer

It degenerates, leading to a drop in progesterone and shedding of the endometrium

Question 9

Which of the following is a function of the hormone inhibin in the male reproductive system?

Accepted Answer

Inhibits the release of GnRH and FSH

Question 10

A woman is experiencing a lack of menstruation (amenorrhea). Her hormone levels show low FSH and LH, but normal estrogen. Which structure is most likely not functioning properly?

Accepted Answer

Anterior pituitary

Question 11

Which of the following best explains why the stratum basalis of the endometrium is not shed during menstruation?

Accepted Answer

It is unresponsive to ovarian hormones and contains stem cells for regeneration

Question 12

During which phase of the uterine cycle does the endometrium prepare for possible embryo implantation, and which hormone is primarily responsible?

Accepted Answer

Secretory phase; progesterone

Question 13

Which of the following is NOT a male secondary sex characteristic influenced by testosterone?

Accepted Answer

Increase in breast tissue

Question 14

A researcher is studying the effects of a drug that blocks FSH receptors in the testes. What is the most likely outcome on spermatogenesis?

Accepted Answer

Decreased ABP production and impaired spermatogenesis

Question 15

Which equation best represents the negative feedback loop involving testosterone in the HPG axis?

Accepted Answer

$$GnRH ightarrow FSH/LH ightarrow Testosterone ightarrow 	ext{Inhibition of GnRH/FSH/LH}$$

Question 16

Which of the following events occurs during the proliferative (preovulatory) phase of the uterine cycle?

Accepted Answer

Regeneration and thickening of the endometrium under estrogen influence

Question 17

A patient has a genetic mutation that prevents the production of androgen-binding protein (ABP) in the testes. What is the most likely consequence?

Accepted Answer

Testosterone will not be concentrated in the seminiferous tubules, impairing spermatogenesis

Question 18

Which of the following best describes the role of the corpus luteum in the ovarian cycle?

Accepted Answer

It secretes progesterone to maintain the endometrium

Question 19

Which of the following is a correct sequence of hormonal events leading to ovulation?

Accepted Answer

$$GnRH ightarrow FSH/LH ightarrow Estrogen ightarrow LH 	ext{ surge} ightarrow Ovulation$$

Question 20

Which of the following best explains why cervical mucus becomes thinner during the proliferative phase of the uterine cycle?

Accepted Answer

Estrogen causes the mucus to thin, facilitating sperm passage

Male and Female Reproductive Systems: Hormonal Regulation, Anatomy, and Physiology

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