Hellkatz: Male Reproductive Physiology

Question 1

What is spermatogenesis?

Answer 1

production of mature haploid spermatozoa from spermatogonial sperm cells

Question 2

What’s unique about male germ cells?

Answer 2

Capable of producing cells that undergo mitosis

Able to produce germ cells that differentiate into spermatozoa throughout life.

Question 3

When do mitosis and meiosis occur in spermatogenesis?

Answer 3

Mitosis begins in the embryo

Mitosis and meiosis occurs through adult life

Question 4

Where does spermatogenesis occur?

Answer 4

seminiferous tubules of testes

Question 5

What’s a spermatogenic wave?

Answer 5

time it takes for reappearance of same stage w/in given segment of seminiferous tubule

*spermatogenesis is staggered throughout hte seminiferous tubule so ALL developmental phases occur at one time

Question 6

What is the purpose of spmeratogenic waves?

Answer 6

ensures that spermatozoa are produced continuously & mature sperm are always available

Question 7

How long is the total spermatogenesis cycle?

Answer 7

64 days

Question 8

How many sperm are produced daily?

Answer 8

100 milion

Question 9

What influences spermatogenesis?

Answer 9

directly proportional to testosterone levels

*decreases in older age goups

Question 10

What regulates testosterone secretion?

Answer 10

NFB from testosterone and inhibin

Question 11

Produces testosterone

Answer 11

testicle

Question 12

produces DHT

Answer 12

prostate

Question 13

produces dihydrioepiandrostendione

Answer 13

adrenal

Question 14

Where are SHBG made and what do they do?

Answer 14

made in liver and sertoli cells, bind androgens and estrogens

Question 15

What steroid receptor acts as a TF?

Answer 15

Androgen Receptor

Question 16

What nourishes developing sperm and secretes androgen binding protein and inhibin?

Answer 16

sertoli cells

Question 17

What stimulates sertoli cells leading to sperm proliferation and differentiation?

Answer 17

Testosterone and FSH

Question 18

What does inhibin do?

Answer 18

inhibits FSH from AP

Question 19

What promotes muscle building, bone growth and Na and water retention?

Answer 19

androgens

Question 20

What is andropause?

Answer 20

androgen def w/ aging

Aging> decreased testosterone> decreased muscle mass and increased abdominal fat

Question 21

What happens to testicular function w/ andropause?

Answer 21

loss of spermatocytes, Leydig cells, Sertoli cells

decrease of testosterone production

compensatory increases in secretion of GnRH and gonadotropins (FSH and LH)

Question 22

Erectile dysfunction, weight gain and gynecomastia are all sxs of…

Answer 22

andropause (d/t shift in estrogen: testosterone ratio)

Question 23

How do you dx andropause?

Answer 23

measure morning total testosterone

Question 24

What are the normal circulating levels of testosterone in males and females?

Answer 24

Males = 0.6 mcg/dL 
Females = 0.03 mcg/dL

Question 25

What are the androgenic effects of hormone replacement?

Answer 25

``` Hypogonadism Hypopituitary f(x) ```

Question 26

What are the anabolic effects of androgens?

Answer 26

muscle building Promotes prot synth → incr. muscle mass & strength [Counters glucocorticoid effects]

Question 27

What type of androgen therapy is good for reversing protein loss?

Answer 27

anabolic > androgenic | opposite is good hormone therapy

Question 28

What is used for testosterone hormone replacement?

Answer 28

Methyl testosterone (testosterone analog)

Question 29

Hepatotoxicity, acute cholestasis and increased tumor incidence w/ chronic use are SE of..

Answer 29

methyl testosterone

Question 30

What synthetic androgen is used to promote muscle growth and has low risk of hepatotoxicity?

Answer 30

Oxandrolene

Question 31

Growth interrruption, priapism, jaundice, hypogonadism, aggressive behavior are se of ....

Answer 31

synthetic androgens

Question 32

Why do synthetic androgens have so many SE?

Answer 32

Bind to MANY different receptors (glucocorticoid, progesterone, estrogen)> multiple effects arromatization of steroids to estradiol compounds> adverse estrogenic efffects

Question 33

What are adverse effects of anabolic steroids in men?

Answer 33

* Gynecomastia * Testicular shrinkage/ reduce sperm count * Impotence * Baldness

Question 34

What are adverse effects of anabolic steroids in women?

Answer 34

* Menstrual irregularities * Clitoris enlargement * Increase in facial & body hair

Question 35

What is the purpose of medical castration drugs?

Answer 35

interfere w/ precocious puberty tx androgen dep cancers reduce libido

Question 36

What should you use if your goal is to shut down the HPO axis?

Answer 36

GnRH agonists/antagonists (don't wipe out locally produced androgens in other tissues--prostate)

Question 37

What should you use if your goal is to reduce androgen signaling in the prostate gland?

Answer 37

androgen receptor antagonists or 5 alpha reductase inhibitors

Question 38

What drug is used to reduce excessive sex drive in men, and treat hirsuitism in women.

Answer 38

Cyproterone acetate

Question 39

What drug is used to tx prostate cancer but may cause gynecomastia and be hepatotoxic?

Answer 39

Flutamide | bicalutamide

Question 40

What is a diuretic that is used to tx hirsutism or acne in women?

Answer 40

spironolactone

Question 41

What is the difference between single/pulsatile GnRH agonists vs continuous GnRH agonists?

Answer 41

Single/pulsatile → stimulatory Continuous → inhibitory but has **IMMEDIATE androgen flare

Question 42

What drugs bind GnRH receptors → block action of GnRH → reduced FSH/LH → reduced testosterone production by testes and have NO immediate androgen flare?

Answer 42

GnRH antagonists

Question 43

What drug is used to assess gonadal response and can improve sperm numbers after 3-6 mos of pulsatile infusion?

Answer 43

Gonadorelin

Question 44

What drug is used to tx advanced prostate cancer and BPH?

Answer 44

Degarelix

Question 45

What is a synthetic GnRH analog used to tx gonadotropoin dependent precocious puberty?

Answer 45

Leuprolide

Question 46

What drug is used to tx ovarian hypersecretion?

Answer 46

Ganirelix | cetrorelix

Question 47

What drugs inhibit the conversion of testosterone to DHT?

Answer 47

5 alpha reductase inhibitors

Question 48

What is androgen specific for growth and maintenance of the prostate gland?

Answer 48

DHT

Question 49

What is used to tx BPH and male patterned baldness?

Answer 49

Finasteride

Question 50

What is used to tx BPH, male pattern bladness, and hirsutism in women?

Answer 50

Dutasteride | slower onset and longer t1/2

Question 51

What is the physiology of an erection?

Answer 51

1) PS stimulation causes production/release of Nitric Oxide (NO) 2) NO binds membrane receptors in vascular smooth muscles 3) induces increase in intracellular cGMP 4) cGMP promotes arteriole dilation which causes penile engorgement (tumescence). 5) Phosphodiesterase 5 in vascular smooth muscle degrades cGMP 6) Vasodilation ensues which results in a flacid penis.

Question 52

What drugs prevent the degradation of GMP and can cause HA, flushing, dyspepsia and nasal congestion?

Answer 52

Sildenafil (viagra), verdena fil and tadalafil

Question 53

What drugs should not be used w/ other nitrates or alpha blockers?

Answer 53

sildenafil