Question 1

Which hormone is released in pulses every 60 to 90 minutes by the hypothalamus to initiate testosterone production?

Accepted Answer

Gonadotropin-releasing hormone (GnRH)

Question 2

What is the primary role of luteinizing hormone (LH) in the process of testosterone synthesis?

Accepted Answer

It binds to receptors on Leydig cells to initiate testosterone synthesis.

Question 3

Which of the following sequences correctly describes the biochemical pathway from cholesterol to testosterone in Leydig cells?

Accepted Answer

Cholesterol $$\rightarrow$$ Pregnanolone $$\rightarrow$$ Testosterone

Question 4

A patient is diagnosed with a deficiency in 5-alpha reductase. Which of the following effects is most likely to be observed?

Accepted Answer

Reduced conversion of testosterone to dihydrotestosterone (DHT) in the skin and prostate

Question 5

Testosterone exerts its biological effects in muscle tissue primarily by:

Accepted Answer

Binding directly to the androgen receptor

Question 6

In which tissues is testosterone converted to estradiol by aromatization, and what receptor does estradiol bind to?

Accepted Answer

Bone and brain; estradiol binds to the estrogen receptor ($$E2R)$$

Question 7

If a drug inhibits the release of GnRH from the hypothalamus, which of the following is the most likely consequence?

Accepted Answer

Decreased LH secretion and reduced testosterone synthesis

Question 8

Which enzyme is responsible for converting testosterone to dihydrotestosterone (DHT) in the prostate gland?

Accepted Answer

5-alpha reductase

Question 9

A mutation causes the androgen receptor (AR) to become nonfunctional in muscle tissue. What is the most likely physiological outcome?

Accepted Answer

Testosterone cannot exert its effects in muscle tissue

Question 10

Which of the following best explains why testosterone must be converted to DHT in the skin and prostate gland?

Accepted Answer

DHT has a higher affinity for the androgen receptor in these tissues

Question 11

A patient with liver dysfunction has impaired metabolism of testosterone. Which of the following is a likely consequence?

Accepted Answer

Prolonged biological effects of testosterone in target tissues

Question 12

Which of the following correctly matches the hormone with its primary site of synthesis?

Accepted Answer

Testosterone – Leydig cells of the testes

Question 13

If a patient has a genetic defect that prevents the conversion of cholesterol to pregnanolone, which hormone's synthesis will be directly impaired?

Accepted Answer

Testosterone

Question 14

Which of the following best describes the role of estradiol ($$E2) in $$the brain?

Accepted Answer

It is produced by the conversion of testosterone via aromatization and binds to the estrogen receptor.

Question 15

A patient is treated with a drug that blocks androgen receptors in the skin. What is the most likely effect?

Accepted Answer

DHT cannot exert its effects in the skin

Question 16

Which of the following is the correct order of hormonal signaling in the hypothalamic-pituitary-gonadal axis for testosterone production?

Accepted Answer

GnRH $$\rightarrow LH$$ $$\rightarrow$$ Testosterone

Question 17

A male patient has normal LH levels but low testosterone. Which of the following is the most likely explanation?

Accepted Answer

Leydig cell dysfunction

Question 18

Which of the following best explains why testosterone must be converted to estradiol in bone tissue?

Accepted Answer

Estradiol is required for bone growth and maintenance via the estrogen receptor

Question 19

If the pituitary gland fails to release LH, which step in testosterone production is directly affected?

Accepted Answer

Stimulation of Leydig cells to convert cholesterol to pregnanolone

Question 20

A researcher is studying the effects of a new drug that increases the activity of aromatase in the brain. What is the most likely outcome?

Accepted Answer

Increased conversion of testosterone to estradiol

Testosterone Production and Mechanisms of Action

Study Guide - Practice Questions