VI-Male Reproduction

Question 1

cholesterol side chain cleavage enzyme function

Answer 1

convert cholesterol to pregnenolone

Question 2

17B-hydroxysteroid dehydrogenase function

17B-HSD3

Answer 2

convert androstenedione to testosterone

Question 3

5a-reductase function

Answer 3

convert testosterone to DHT

Question 4

aromatase function

Answer 4

convert testosterone to estradiol

Question 5

effects of testosterone

Answer 5

-muscle mass
-bone formation
-spermatogenesis
-erythropoiesis

Question 6

effects of DHT

Answer 6

masculinzation of external genitalia
-prostate growth
-hair growth

Question 7

effects of estradiol

Answer 7

-bone resorption
-epiphyseal closure long bones
-hypothalamic feedback
-fat mass
-libido

Question 8

steroid abuse mechanism

Answer 8

constant levels of testosterone induce neg feedback so dec LH and FSH = inhibit spermatogenesis, testicular atrophy

Question 9

LH function

Answer 9

bind on leydig cells to stim testosterone production thru GPCR

Question 10

FSH function

Answer 10

stimulate sertoli cells to produce ABP
-control sertoli cell prolif and seminiferous tubule growth during testes devel

Question 11

sertoli cell function

Answer 11

-support spermatogonia
-signal spermatogenesis
-produce inhibin B
-produce androgen binding protein

Question 12

male sex act stages

Answer 12

1. erection
2. lubricatin
3. emission
4. ejaculation

Question 13

parasymps on erection

Answer 13

-initiate erection by relaxing vasculature/dilating thru Ach and NO
-secrete mucus from bulbourethral gland for lubrication

Question 14

hypergonadism causes

Answer 14

1. activating mutations of LH receptors
2. congenital adrenal hyperplasia
3. androgen producing tumors

Question 15

hypogonadism presentaiton

Answer 15

in kids: underdev muscles, sex organs, absent/delayed spermatogenesis, eunuchoid body propotions

in adults: dec bone mass, anemia, muscle atrophy, dec sex function, depression

Question 16

hypergonadotropic hypogonadism

primary hypogonadism

Answer 16

from testicular dysfunction so dec testicular production = inc LH and FSH bc no neg feedback
-cryptorchidism (undescend testes), klinefelter syndrome, chemotherapy

Question 17

hypogonadotropic hypogonadism

secondary hypogonadism

Answer 17

from hypothalamic or pituitary dysfunction so low LH, FSH = low testosterone
-kallmann syndrome, chronic systemic illness, drugs