Male Reproductive Hormones Flashcards
(35 cards)
What are the two main functions of the testes?
- Sperm production and
- Testosterone production.
Why are the testes located in the scrotum instead of inside the body?
To maintain a temperature 2-3 C lower than body temperature, which is needed for sperm production.
Where is sperm stored before ejaculation?
In the epididymis.
What is the pathway of sperm during ejaculation?
Epididymis -> Ductus deferens -> Urethra -> Penis.
What fluids mix with sperm to form semen?
Fluids from the seminal vesicles and prostate gland.
What are androgens?
Male sex hormones, mainly testosterone and DHT (dihydrotestosterone)
Where are androgens made in males?
Leydig cells in the testes.
What enzyme converts testosterone into DHT?
5a -reductase
What are the effects of DHT?
It helps with prostate growth, facial hair, deep voice, and male-pattern baldness.
What are the main functions of androgens during development?
Help with sperm production and male reproductive organ growth
What changes do androgens cause during puberty?
Facial & body hair growthMuscle growthDeep voiceIncreased sex drive
What are the effects of androgens in adulthood?
Maintains muscle massKeeps bones strongIncreases red blood cells
What happens to androgens as men get older?
Testosterone levels slowly decrease, leading to thinning hair and lower muscle mass
What is DHEA (Dehydroepiandrosterone)?
A weak androgen that helps with pubic & body hair growth
What is androstenedione?
An androgen that may affect aggressive behavior
What is androstenediol?
A weak androgen that stimulates the immune system
What hormone tells the testes to make testosterone?
Luteinizing hormone (LH) from the pituitary gland.
What controls LH release?
Gonadotropin-releasing hormone (GnRH) from the hypothalamus.
How does testosterone affect its own production?
It stops LH and GnRH release (negative feedback)
How does testosterone enter cells?
It crosses the cell membrane and binds to androgen receptors.
What happens when testosterone binds to its receptor?
It activates genes that make proteins for male traits.
What happens if a man has too much testosterone?
Increased aggressionHigh blood pressureShuts down natural sperm production
What condition happens when a man has too little testosterone?
Hypogonadism - low sex drive, muscle loss, and fatigue.
What happens in testicular feminization (Androgen Insensitivity Syndrome)?
The body cannot respond to testosterone, so a genetic male (XY) develops female traits.
