reproductive endo (4) Flashcards
what secretes sex hormones
Adrenal cortex
Placenta
Gonads (testis and overy)
classes of sex steroids
Pregnanes (21C)
androgens and androstanes (19C)
estrogens or estranes (18C)
what is the primary male hormone
Testosterone
what is more potenent, DHEA, testosterone, androstenedione, or DHT
DHT, then Testosterone
what is testosterone converted into
DHT
how is testosterone converted to DHT
by the enzyme 5alpha reductase
what is the primary female hormones
Progesterone
estradiol
what type of hormone is progesterone
Progestin
what type of hromone is estrodiol
estrongen
what is the importatance of progesterone in steroid synth
precursor for other steroids
how is estrdiol made
produced from androgens by enzyme aromatase
can roids be stored
Lipophilic, so can’t be stored
what controls synth and secretion of roids
neuroendocrine system
what organ are included in the reproductive axis
hypothalamus
anterior pituitar gland
gonads
when is GnRH released
a pulsatile
how do pulsitile hormones generate
spontaneously produce action potentials resulting in secretory bursts of GnRH
where is GnRH secereted from
pacemaker neurons in the hypothalamus
how do pacemaker neurons develop a pace
LEaky to Na, to eventually fire and release GRNH
why are pulsmakers needed for some hormones
Body will get used to the hormone
when is Luteinizing hormone and follicle stimulating hormone released
In a pulsating fashion in response to GnRH
where is LH and FSH released from
Anterior pituitary
what does LH and FSH stimulate
Pulsatile secretion of gonadal steroid
what are the feeback loops on GnRH neurons and gonadotropes
gonadal steroids negative feedback on GnRH and LH secretion
females: E2 postiive feedback on LH prior to ovulation
what is the feedback loop given by testosterone
Inhibits GnRH, FSH, and LH
what is the feedack loop given by estradiol and progesterone
Inhibit GnRH, FSH, and LH
during reproductive cycle: estradiol from ovary stimulates LH
what do the action of sex steroids have on gonads
trascribe poteins that Regulate gametogenesis and hormone synth
what do gonadal steroid regulate in reprodcutvive organ as well as accessory glands
Protein synth in reproductive organs, male accessory glands, uterus, breast, and brain
what are the cells of the testis
Speratic cells (gametes) Leydig cells/interstitial cells Sertoli cells/ sustentacular cells
what is included in psermatic cells
Mitotically active spermatogonia
Meiotic spermatocytes
how does spermatogenesis process in direction
spermatic cells move through the wall of seminiferous tubules
- away from basal lamina to apical surface and lumen
where are leydig/interstitial cells found
outside the seminiferous tubules
what do leydig cells do
Synth Testosterone
what makes leydig cells sythesize testosterone
LH
what is the roll of testosterone in the gonads
regulates spermatogenesis
what is the roll of testosterone in the brain
regulates Sexual behavior after being aromatzed to E2
what does testosterone do to the whole body
regulates secondary sex characteristics
what are the sertoli cell’s roll in the tests
- Are the epithelial cells lining the seminiferous tubules
- regualte spermatogenesis
- produce inhibin
- produce androgen binding protein
- secrete tubular fluid
what hormone do sertoli cells respond to regulate spermatogenesis and production of inhibin
FSH
what is the action of Inhibin
negative feedback action on FSH secretion at the level of the anterior pituitar
what kind of hormone is inhibin
Peptide
what is the roll of androgen binding protein
sequester T in the testes so spermatogenesis is continuous
what does tubular fluid do
Provide nutrient support for spermatozoa
what shape are sertoli cells
Columnar
what recepot do leidig cels have that sertoli cells do not have
LH receptors on leydig
FSH on sertoli cells
what is the benifit of having leydig and sertoli cells separate
can develop sex characteristics without having to create sperm
what are the effects of testicular homromes
sexual differentiation
Develop and maintence of secondary sex characterisitics
Libido
Sexual behavior
effects of testosterone on females
regulate bone growth
Stimulate muscle growth
Stimulate erythropoiesis
what leads to sex differentiation in the featus
test from the featal testies
why would testosterone be converted to estrogen
Increase sex drive
what is testosterone converted to in the target tissue of the peripheral
DHT
Estradiol
can DHT be turned into estradiol
No, non-aromatizable
where is testosterone converted to estradiol
aromatase in brain and bone
why inhibit 5alpha reductase
treat hair loss since DHT promotes hiar loss in male pattern baldness
why inhibit aromatase
treat breast and prostate cancers
what is the male counterpart to menopause
Andropause
severity of andropause
Much less severe because no physiological changes
changes from andropause
- Increase in emo disorders with aging
- noobvious decline in reproductive function
- test decreases, but still fertile
is test decline associated with emo problems
No
4 cells of female reproduction
OOcyte
Theca cells
Granulosa cells
Luteal cells
what surrounds each oocyte
Ovarian follicle
where are all oocytes stopped right after birth
Prophase of meisis 1
how many ovum are released per cycle
1 typically
what do theca cells do
Surround each follicle
what is the function of theca cells similar to
Leydig cells
where are Oocytes stoped at ovulation
meiosis
when does an oocyte complete meisosi
fertilization
what do theca cells respond to
LH
what are granulosa cells
Epithelial cells of the follicle (analgous to sertoli cells)
how many layers of grnulosa cells are there in a follicle
1+ in the early follicle
granulosas continue to surround growing follicles as they fill with fluid
what does the follicle eventually develop into
Cumulus oophorus
when do luteal cells form
Present after ovulation when the theca and granula cells from a postovulatory follicle are transformed into the cells of the corpus luteum
what happens to follicle growth during the fetal and prepbertal development
Primordial follicles continueally mature into primary, preantral and early antral follicles
- eventually under atresia
what happens to the follicles after puberty
Develop during the ovarian/menstrual cycle
- undergo atresia
- progress to large antral follicle
what hapens to the large antral follicles
A dominant follicle emerges and eventually ovulates
what do theca cells respond to
Respond to LH
what do theca cells snth
Androstenedione
where does androstenedione go
Diffuses into granulosa cell
diffuse into the systemic circulation
what do granulosa cells do to androstenedione in response to FSH
convert androstenedione to estrogen which is then converted to estradiol
what is the action of estradiol
Stimulates granulosa cell function and replication
regulates oocyte development
regulates female secondary sex characteristics
regulate bone turnover and arterial function
what does estradiol inhibit
GnRH and LH sescretion
what is secreted as a negative feedback effort on FSH secretion
Secretion of inhibin
what receptors do larger follicles have lots of
More LH and FSH receptors
because larger follicles have lots of LH and FSH receptors, what do larger follicles tend to produce lots of
E2
Inhibin
what do E2 and inhibin regulate together
Ovarian cycle
what are the steps of the ovarian cycle
- Gonadotropin increase to stimulate follicular development
- increase E2 and inhibin; dominan folicle selection
- FSH decrease, E2 peaks, LH surge
- meiosis I completed, ovulation, CL formation
- Increase E2 and P, inhibit gonadotropins
- CL regression, decrease steriods, gonadotropins increase
- restart of cycle
what does the slight rise of gonadotropin do during the ovarian cycle
leads to growth of follicle leading to estrodiol
what happens in the menstrual phase
when the CL regresses
steroid support for uterine endometrium is lost
what happens in the proliferative phase
Follicular E2 stimulate proliferation of the endometrium
what signifies the end of the follicular phase
Ovulation
Cl fomration
what happens in the luteal phase
P and E2 stimulate uterine secretory activity
increase glandular production of glycogen
increase angiogenesis
decrease contactility
what ends the luteal phase
Decrease in gonadotropics
CL regresses
- restart cycle
what happens if pregnancy occures
placentra produces human chorionic gonadotropin (
what is human chorionic gonadotropin
similar to LH
- maintains luteal steroidogenesis until placenta develops fully
what is menopause
Cessation of menstrual cycles primarily due to ovarian failure
what causes ovarian follicles to go away in menopause
atresia
what are the hormonal consequences of menopause
Lose ovarian sterios
gonadotropin and inhibin secreted highly
increase reliance on adrenal steroids
what determines gonadal sex
SRY protein
where is the SRY gene found
Y chromsome
what is the action of SRY protein
Directs indifferent gonad to become testis
what hormones does the fetal testis produce to regulate sexual differentiation of internal genitalia
T
Anti-mullerian hormone
what are the tubules of the developing undifferentiated gonad
Wolffian duct
Mullerian ducts
how do male hormones act to differentiate to male gonads
T stimulate proliferation of Wolfian duct
AMH causes Mullerian duct to regress
what does the wolffian duct become
the tubules associated with the male reproductive tract
what steroids does the developing female gonads produce
No significant production of gonadal steroids
how does the lack of steroids affect female reproduction growth
Absence of T causes regression of the wolffian duct
absence of AMH results in proliferation or maintenace of Mullerian duct system
what does the Mullerian duct system become
Tubules of the female reproductive tract
how long is the fetus undifferentaited
9 weeks
what external sex organs does the fetus have in both males and females
Genital tubercle
Urogenital fold
Labioscrtoal fold/genital folding
what stimulates the change of undifferentiated external sex organs to differentiated in males
Androgens( T converted to DHT in periphery) from the developing testing
what does androgens from the developing testes cause the genital tubercle, urogenital fold, and labioscrotal folds to becomes
Genital tubercle-> glans of penis
Urogenital fold-> urethral and surrounding penis
Labioscrotal folds_> Scrotum and skin of penis
what leads to the development of the female external genitals
abscence of androgens
what does the abscenes of androgesn cause the genital tubucle, urogenital fold, and labioscrotal fold to become
Genital tubercle -> glans of clitoris
Urogenital fold-> labia minor and urethral opeing
Labioscrotal fold -> labia majora
what causes the brain to sexually differentiate
effect of T aromatized to E2 in developing male
what is Congenital adrenal hyperplasia
Adrenal enzyme deficiency resulting in excess production of adrenal androgens
what causes Congenital adrenal hyperplasia
caused by 1+ mutation
is severity of congenital adrenal hyperplasia the same
Varies depending on the mutation
what does a 21alpha hydroxylase mutation lead to in congenital adrenal hyperplasia
Impairs synth of cortisol
decreases negative feeback of cortisol on ACTH secretion
increased stimulation of adrenal cortex
increased production of adrenal anrogens
what are the clinical signs of Congenital adrenal hyperplasia from 21alpha hydrozylase mutation
genotype XX
phenotype is more male than female
- effect on gonads and internal genitalia
what is the penis, scrotum, and prostate gland dependent on to grow
DHT-dependent
what does 5alpha reductase deficiency (Guevodoces clinically
- Failure of differentiation of eternal genitalia early in life
- increased T at puberity leads to some differnetaion
what is the phenotype and genotype of a 5alpha reductase deficncy
XY
phenotype female at brith until early pubery
- effects on gonads and internal genitalia
what causes Testicular feminization or androgen insensitivity
Lack of functional androgen receptor (T and DHT)
what is the clinical signs of Testicular feminization/ androgen insensitivity
Genotype XY
phenotype female, condition diagnosed at puberty
- effects on gonads and internal genitalia
do circulating hormones increase or decrease with pregnancy
dramatically increase of circulating steroids hormones due to placental producation
how long does it take for the CL to regress in pregnancy
after 3 months
what supports luteal steroidogenesis after CL regression in pregnancy
HCG
what stimualtes grwoth of myometrium in pregnancy
Placental E2
what is the action of placental P
reduces uterine contractily
stimulates vasodilation
why is looking at pregancy important for a dentist
More susceptible to gingivitis and periodontitis due to elevated steroids hromones
Medication and X-rays affect fetus
comfort during exam or procedure
