sex hormones and sexual differentiation

Question 1

hormones

Answer 1

chemical substance secreted by the endocrine glands into the bloodstream

Question 2

testosterone

Answer 2

• androgen

- secreted by the testes, ovaries and adrenal glands

Question 3

estrogens

Answer 3

secreted by the ovaries and testes

Question 4

progesterone

Answer 4

secreted by the ovaries and adrenal glands

- not exclusively female

Question 5

prolactin

Answer 5

produced in the pituitary

- stimulates production of milk

Question 6

oxytocin

Answer 6

• stimulates ejection of milk

- produced by cuddling, orgasms, loving feelings

Question 7

GnRH - gonadotropin releasing hormone

Answer 7

• secreted by the hypothalamus

- stimulates production of FSH and LH in the pituitary

Question 8

FSH - Follicle stimulating hormone

Answer 8

• controls sperm production and ovum follicle development

- responds to GnRH

Question 9

LH - luteinizing hormone

Answer 9

• controls testosterone production and ovulation

Question 10

inhibin

Answer 10

secreted by testes and ovaries to suppress FSH production

• negative feedback loop
• creates monthly cycle of ova, daily sperm production

Question 11

HPG axis

Answer 11

ovaries :

• FSH from pituitary gland initiates follicular development
• LH causes estrogen secretion -> ovum is released and travels down fallopian tube

testes:
FSH - sperm production
LH - Testosterone production

Question 12

prenatal sexual differentiation

Answer 12

• 7th week gestation in males, 10th week in females for sexual differentiation

Question 13

SRY region

Answer 13

-presence of SRY region on Y chromosome is key for sex determining

Question 14

TDF (testes-determining region)

Answer 14

produced at SRY region

- if proper development occurs, leads to testes development

Question 15

duct systems

Answer 15

mullerian - female

wolffian - male

Question 16

prenatal hormones : in absence of TDF and ovaries…

Answer 16

• wolffian ducts degenerate
• mullerian ducts develop into fallopian tubes, uterus, vagina
• tubercle develops into female external genitalia

Question 17

prenatal hormones : in presence of testes

Answer 17

• secretion of anti-mullerian hormone
• mullerian ducts degenerate
• wolffian ducts develop into epidermis, vas deferens, ejaculatory duct
• tubercle develops into external genitalia

Question 18

brain differentiation

Answer 18

• male/female brains very similar
• early sex-diff determines estrogen sensitivity of cells in hypothalamus
• presence of T during fetal development desensitizes to estrogen
• crucial to hypothalamic-pituitary-gonad feedback loop

Question 19

homologous sex organs

Answer 19

glans of penis-glans of clitoris
scrotal sac-labia majora
testes-ovaries
prostate gland-skenes gland
cowpers gland-bartholins glands

Question 20

what makes sex/gender

Answer 20

• chromosomal gender
• gonadal gender
• prenatal hormonal gender
• brain differentiation
• internal organs
• external genital appearance
• pubertal hormonal gender
• assigned gener
• gender identity
  if all variables agree, sex is determined

Question 21

congenital adrenal hyperplasia (CAH)

Answer 21

• genetic female who develops ovaries as fetus
• during prenatal development, adrenal gland produces excess androgens
• external genitals partially male in appearance
• labia partially/totally fused so no vaginal opening
• clitoris enlarged to size of penis
• at birth can be identified as male
• generally have female gender identity

Question 22

androgen insensitivity syndrome (AIS)

Answer 22

• body cells of genetic males are unable to respond typically to T
• infants genitals appear female with undescended testes
• short vagina with no cervix, no internal reproductive organs
• may produce breasts

Question 23

intersex and genital reconstruction

Answer 23

• problem of stigma and trauma
• parents distress should not be treated by surgery
• mental health care essential
• honest, complete medical disclosure
• should be assigned a gender without surgery

Question 24

4 phases of menstruation

Answer 24

• follicular/proliferative
• ovulation
• luteal (14 days before menstruation)
• menstruation/secretory