Male Hormones (memorizables)

Question 1

What is the role of each of the following locations in sperm production?
• Seminiferous Tubules
• Epidydimus
• Vas Deferens

Answer 1

Semineferous Tubules
• Sperm production

Epidydimus
• Sperm Maturation (18-24 hrs)
• Sperm Motility

Vas Deferens
• Stores sperm for up to a month

Question 2

What are 3 general functions of sertoli cells?

Answer 2

1. Nutrients for sperm
2. Blood Testis Barrier
3. Elimination of Defective Sperm

Question 3

What 4 things are produced by the sertoli cells?

Answer 3

1. AMH
2. Inhibin
3. Estrogen
4. Growth Factor for Leydig Cells

Question 4

When do leydig cells start to produce testosterone. what is the significance of this timing?

Answer 4

Leydig cells begin secreting testosterone at around 8 weeks (WHEN ULTRASOUND CAN TELL YOU IF ITS A BOY) and it peaks at 12-18 weeks
**Important for gender assignment

Question 5

What reaction in testosterone synthesis is catalyzed by 3beta hydroxysteroid reductase?

Answer 5

DHEA = 3B-HSR => Androsteindione

Question 6

What enzyme converts androsteindione to testosterone?

Answer 6

17Beta-Hydroxysteroid dehydrogenase

Question 7

What Hormone actions are specific to testosterone?

Answer 7

• Differentiation of epididymis, vas deferens, seminal vesicles, and internal genitalia EXCLUDING the PROSTATE
• Growth spurt: penis, seminal vesicles, sperm, muscle, RBCs (EPO stimulation), decreased body fat, increased BMR, FIGHTS DEPRESSION
• Deepening of the voice
• Closing of epiphyseal plates (via testosterone conversion to estrogen)
• Libido

Question 8

What are the primary functions of DHT?

Answer 8

Early:
•Differentiation of penis, scrotum, and prostate

Late:
• Prostate growth, balding, sebaceous gland activity

Question 9

Note: Testosterone levels do NOT change with cholesterol lowering drugs

ALSO, Cholesterol is INVERSELY proportional to estrogen

Answer 9

Note: Testosterone levels do NOT change with cholesterol lowering drugs

ALSO, Cholesterol is INVERSELY proportional to estrogen