Q2: sex hormones

Question 1

which cells secrete testosterone/produce sperm

Answer 1

leydig vells; secrete testosterone (interstitial cells)

seminiferous tubules produce sperm (they are the bulk of testis)

Question 2

what 3 hormones are involved in male reproductive function

Answer 2

testosterone , dihydrotestosterone (more potent than testosterone) , estradiol

Question 3

what what 2 hormones of the testes have no known role in male reproductive function

Answer 3

dehydroepiandrosterone (DHEA) and androsternedione

Question 4

what are the effects of testosterone

Answer 4

• masculinizes reproductive tract/external genitalia.
• promotes descent of testes into scrotum
• promotes growth and maturation of reproductive system at puberty
• essential for spermatogenesis
• maintains reproductive tract throughout adulthood
• develops sex drive at puberty
• gonadotropin hormone secretion control (include fsh and lh)

secnodary: hair, voice, muscles

Question 5

what are the nonreproductive actions of testosterone

Answer 5

• protein anabolic effect
• bone growth at puberty
• clooses epiphyseal plates after being converted to estrogen by aromatase
• aggressiveness

Question 6

when are there spikes in testosterome throughout life

Answer 6

spike after fertilization and drop. then another spike before the first year of age. then testosterone is low until puberty. This increase in testosterone induces sperm production.
-drop in senior years

Question 7

what is SRY

Answer 7

sex determining region of the Y chromosome

Question 8

what are the destinations of testosterone (pathway from production to target cells)

Answer 8

it may enter seminiferous tubules (from leydig, site of production) and induce sperm production. some also enters into circulation. in blood 98% travels bound to serum proteins and only 2% is free.

• at target cells binds to ANDROGEN RECEPTORS>
• location on membrane, cytoplasm or bone depends on cell for the androgen receptors. testosterone androgen receptor complex either activates cell signaling pathway (nongenomic) or gene transcription (genomic)

Question 9

describe function of GnRh and its feedback inhibition

Answer 9

hypothalamus releases gonadotropin releasing hormone (GnRh) into anterior pituitary. it stimulates secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from gonadotropic cells
-feedback inhibition; sex hormones inhibits Kiss1 neurons from secreting kisspeptin. (kiss peptin stimulates GnRH release) – neg feedback

Question 10

what does FSH / LH do?

Answer 10

FSH stimulates sertoli cells (sustentocytes) to release androgen binding protein (ABP)
-abp keeps concentration of testosterone in spermatogenic cells high, stimulates spermatogenesis

LH stimulates testosterone secretion in leydig cells

Question 11

how is testosterone regulated ?

function of inhibin and kiss1neurons

Answer 11

inhibiition of kiss1 neurons when theres a lot of testosterone (kisseptin stimulates gnrh release)
-lots of testosterone inhibits release of LH from anterior pituitary

INHIBIN: protein hormone from sertoli cells, regulates spermatogneeis. high sperm count stimulates inhibin release, it inhibits release of FSH from anterior pituitary

Question 12

what is estradiol

Answer 12

most active estrogen

estrogen= from ovaries

Question 13

when is progesterone produced (which phase) in large amounts

Answer 13

luteal phase

Question 14

where are estrogen and progesterone made?

Answer 14

synthesized and released by granulosa cells, no storage of the hormones

Question 15

what % of estradiol is free, sex hormone binding globulin (SHBG), corticosteroid binding globulin (CBG) and albumin bound?

Answer 15

free: 2%

SHBG: 37%
CBG : .1%
albumin: 61%

Question 16

WHAT % OF PROGESTERONE IS FREE, SHBG, CBG, ALBUMIN bound?

Answer 16

free: 2.5%
SHBG: .5%
CBG: 18%
albumin : 79%

Question 17

what % of testosterone is free, bound to SHBG, CBG, albumin?

Answer 17

free: 1.5%
SHBG: 66%
CBG: 2.5%
albumin: 30%

Question 18

what are the functions of estrogen

Answer 18

• ova maturation/release
• development of physical characteristics
• transport of sperm from vagina to egg
• development of breast in anticipation of lactation
• fat deposition
• bone density increase
• close epiphyseal plates
• improves blood cholesterole by increasing HDL and decreasing LDL
• promotes vasodilation by increasing NO production in arterioles

Question 19

what is the function of progesteron

Answer 19

• prepare suitable environment for nourishing developing embryo
• contributes to milk production

Question 20

what are the 2 phases of the ovarian cyclw

Answer 20

follicular phase: presenece of maturing follicles
luteal phase: corpus luteum (progesterone)
-corpus luteum secretes hormones to prepare female reproductive tract for pregnancy. in case releaserd egg is ferilized. degeneration of corpus luteum signals end of luteal phase.

Question 21

what are thecal cells

Answer 21

endocrine cells of ovarian follicles. in interfollicular stroma which enclose granulosa cells. the granulosa cell surrounds ovum and antrunm, which is at the center of the follicle.
LH stimulates theca cells to produce androgen.
androgen diffuses from thecal cells into granulosa cells.
fsh stimulates granulosa cells to convert androgen into estrogen.
-some estrogen are secreted into blood and induce systemic effects while the other portion fo estrogen remains within the follicle, and contributes to follicle maturation.

Question 22

whats ovarian hyperandrogenism

Answer 22

high androgen is related to excessive proliferation of theca cells. (low= theca cell dysfunction)

Question 23

describe hormones throughout entire follicular phase

Answer 23

follicular phase: fsh is higher than LH. FSH and LH stimulate oocyte development and follicle growth. the follicle produces estrogen. as estrogen levels increase, endometrium thickens…

• the rising estrogen inhibits FSH secretion from anterior pituitary. FSH levels are further decreased since the follicle releases inhibin (which decreases FSH too from AP).
• estrogen continuesto be produced and estrogen levels increase (gramulosa cells keep making it)
• since estrogen ONLY inhibts fsh, LH continues to increase
• both estrogen AND progesterone are needed to supress LH secretion (not just estrogen)
• estrogen levels hit a peak, at this point it stimulates kiss1neurons to release kisspeptin which induces hypothal to release GnRH, FSH and LH-> spike in both.
• fsh not as intense bc follicle is still releasing inhibit which only impacts fsh. estrogen levels start to decrease as granulosa cells reduce production.
• surge in LH triggers ovulation (ends follicular phase)

Question 24

how does kiss1neurons impact female ovarian cycle

Answer 24

kisspeptin release, stimulates GnRH just like in men . gnrh stims release of LH and FSH. the kiss1 activity can be inhibited by rising levels of estrogen

Question 25

describe hormones from end of follicular phase through luteal phase

Answer 25

surge in LH stimulates corpus luteum development. the level of progesterone and estrogen starts to rise as they are secreted from corpus luteum. high level of progesterone and estrogen correlates w lower levels of LH and FSH secretion from anterior pituitary. progesterone increases number of blood vessels and secretory glands in endometrium.
-if no fertilization, corpus luteum degenerates-> decrease in progesterone and estrogen. as estrogen decreases, inhibition of anterior pituitary from releasing LH and FSH ceases so LH and FSH levels increase and the ovarian cycle starts again

Question 26

how does temperature chagne w ovarian cycle

Answer 26

around day 15 (luteal phase) temperature spikes up, stays higher during luteal phase,lower in follicular phase..

Question 27

list pregnancy impact on mouth

Answer 27

preg gingivitis, tooth decay (carbs and acid from morning sickness)
preg tumors (overgrowths on tissues on gums, may be related to excess plaque. bleed easily, go away after birth)