Lec 19 Reproductive I

Question 1

What is the function of leydig cells?

Answer 1

secrete testosterone

Question 2

What are the functions of sertoli cells?

Answer 2

• MIF
• androgen binding protein
• inhibin
• blood-testis barrier
• nourish germ cells
• aromatize T to estrogens

Question 3

What is testis determining factor?

Answer 3

induces development of testes from indifferent gonad; gene on Y chromosome

Question 4

What is function of MIF in fetal testis?

Answer 4

causes regression of mullerian structures

Question 5

What is function of testosterone in fetal testis?

Answer 5

induces development of wolffian structures

Question 6

What is difference between action of testosterone and DHT in fetal development?

Answer 6

• bind same androgen receptor but DHT has higher affinity
• T needed for wolffian duct development
• DHT needed for external genitalia and prostate development

Question 7

What is difference between action of testosterone and DHT in puberty/adulthood?

Answer 7

• testosterone needed for MSK development, pubic/axillary hair, spermatogenesis, libido
• DHT needed for full secondary sexual hair, acne, temporal hairline recession, prostate enlargement and diseases

Question 8

What is the phenotype at birth of someone with 5-alpha-reductase deficiency?

Answer 8

variable phenotype may be undetermined sex –> become phenotypic males at puberty

Question 9

What happens in 5-alpha reductase deficiency?

Answer 9

XY genotype
low DHT:T ratio b/c can’t convert
as adults normal libido and fertility/musculature but NO balding or prostatic disease!

Question 10

What is androgen insensitivity syndrome?

Answer 10

genotypic male but phenotypic female
mutation of androgen receptors –> have high LH, FSH, T
present with primary amenorrhea and have undescended testicles

Question 11

What is the first measurable indication of puberty?

Answer 11

DHEA-sulfate = weak adrenal androgen

Question 12

What is effect of FSH in males?

Answer 12

stimulates sertoli cells to produce inhibin which feeds back on GnRH secretion from hypothalamus

Question 13

What is effect of LH in males?

Answer 13

stimulates testosterone production by leydig cells which feeds back on GnRH secretion from hypothalamus

Question 14

What is effect of FSH in females?

Answer 14

FSH stimulates granuosa cells to produce estrogen and follicles to secrete inhibin

Question 15

What is effect of LH in females?

Answer 15

LH triggers ovulation and later stimulates theca cells to secrete androgesn

Question 16

What happens if you give GnHR in non-pulsatile manner?

Answer 16

causes medical castration = intially increase FSH/LH then cause desensitization

used to treat uterine fibroids and prostate cancer

Question 17

What is kallman’s syndrome?

Answer 17

most common cause of hypogonadotropic hypogonadism
can be hereditary or sporadic
deletion in KAL gene
phenotypic male at birth; fail to mature at puberty b/c lack GnRH
eunichoidal proportions due to lack of pubertal testosterone
associated with anosmia

Question 18

What DSD is associated with anosmia?

Answer 18

kallmans syndrome

Question 19

How does kallman’s syndrome present?

Answer 19

failure to go through puberty

Question 20

What is klinefelter’s syndrome?

Answer 20

47 XXY
prematurely senescent testes
seminiferous tubule dysgenesis; azospermia; and lerydig cell failure
low/normal testosterone, high FSH and LH and estrogen
mental retardation

Question 21

What does azospermia and high FSH suggest?

Answer 21

primary testicular failure as cause of low sperm