androgens

Question 1

roles of sertoli cells

Answer 1

Sertoli = Support + nourish spermatagonia, 1° and 2°  spermacyte + spermatids
regulate spermatogenesis
secrete inhibin
secrete ABP
produce MIF

Question 2

form blood-testis barrier

Answer 2

tight junctions between adjacent sertoli cells prevents blood through
isolate gametes from autoimmune attack

Question 3

affect of ↑ temperature on sertoli cells

Answer 3

occurs with varicocele or cryptochordism
↓ sperm production
↓ inhibin

Question 4

undifferentiated germ cell in male

Answer 4

spermatagonia

along outside of seminferous tubules (not mature yet)

Question 5

types of androgen

Answer 5

testosterone
DHT (most potent)
androstenedione (least potent)

Question 6

roles of testosterone

Answer 6

mesonephric ducts (wolffian) into internal genitalia
SEED: seminal vesicle, ejaculatory duct, epididymis, ductus deferens
growth spurt: penis, seminal vesicles, sperm, muscles, RBCs
deepens voice
closing of epiphyseal plates (due to testosterone → estrogen; don’t give T to prepubertal boy)
libido (male + female)

Question 7

role of DHT

Answer 7

early: urogenital sinus → external genitalia: penis, scrotum, prostate
late: prostate growth, balding, sebaceous gland activity

Question 8

male androgens are converted to estrogens by

Answer 8

aromatase (mostly in adipose tissue + testes sertoli cells0

Question 9

obese patients have low testosterone because

Answer 9

testosterone is converted to estrogens in adipose tissue

Question 10

genotype of androgen insensitivity syndrome

Answer 10

46 XY

Question 11

defect in androgen receptor in 46 X,Y→
testes present
sense no testosterone → no SEED
sense no DHT → no male external genitalia, urogenital sinus → LOWER VAGINA PRESENT
MIF present → no paramesonephric ducts (no upper vagina, uterus, etc)
female external genitalia - LOOK FEMALE (testosterone converted to estrogen)

Answer 11

androgen insensitivity syndrome

Question 12

lumps in labia majora

Answer 12

= testes, remove to prevent malignancy

androgen insensitivity syndrome

Question 13

genotype of 5α reductase deficiency

Answer 13

46 X,Y

Question 14

46 X,Y with ambiguous genitalia until puberty when ↑ testosterone is sufficient to cause masculinization + ↑ growth of external genitalia

Answer 14

5α reductase deficiency

no embryonic DHT: no male external genitalia, prostate

Question 15

↑ testosterone, ↑ estrogen, ↑ LH

Answer 15

androgen insensitivity syndrome

Question 16

ovaries present
virilized or amibigous external genitalia
excessive inappropriate exposure to androgenic steroids during early gestation (congenital adrenal hyperplasia: 21B or 11B hydroxylase deficiency or exogenous admin of androgens during pregnancy)

Answer 16

female pseudohermaphrodite (XX)

Question 17

testes present

female or ambiguous external genitalia

Answer 17

male pseudohermaphrodite (XY)
seen in androgen insensitivity syndrome

Question 18

↑ testosterone, ↓ LH

Answer 18

testosterone-secreting tumor or

exogenous steroids

Question 19

↓ testosterone, ↑ LH

Answer 19

1° hypogonadism

Question 20

↓ testosterone, ↓ LH (↓ GnRH)

Answer 20

hypogonadotropic hypogonadism (Kallman syndrome)

Question 21

small testes/penis
low sperm count or 1° amenorrhea (never started menstruating)
no secondary sex characteristics (male/female)
ANOSMIA (can’t smell)

Answer 21

Kallmann syndrome

Question 22

x-linked KAL chain defect (more common in men)

Answer 22

Kallmann syndrome

Question 23

defective migration of GnRH cells in hypothalamus + formation of olfactory bulb

Answer 23

Kallmann syndrome

Question 24

both ovary + testicular tissue present (ovotestis)

ambiguous genitalia

Answer 24

true hermaphrodite

46XX or 47 XXY