Menstrual Cycle Flashcards
Ovarian Cycle first phase
-Which hormones are involved?
Follicular phase: development of follicles
- controlled by GnRH –> FSH + LH
- LH stimulates thecal cells to produce androgens
FSH stimulates granulosa cells to
- secrete estrogens for endometrial development
- increase aromatase enzyme for the conversion of testosterone to estradiol
- secrete inhibin to inhibit FSH
Pathway of steroid hormone synthesis in males and females
- cholesterol becomes progestins or androstenedione
- androstenedion can become estrone or estriol with help from aromerase
- androstenedione can become testosterone
- Testosterone can become dihydrotestosterone
- testosterone can become estradiol with help from aromarase
Follicles release small amounts of estrogen and inhibin
negative feedback
-inhibit GnRH and FSH/LH
High levels of estrogen are met
Positive feedback
-increase gnrh, fsh, and lh release
LH surge
- ovulation of oocyte from most mature follicle
- primary oocyte becomes secondary oocyte
luteal phase
-explain LH’s role
corpus luteum acts as endocrine organ
LH stimulates corpus luteun to produce progesterone, estrogen, and inhibin
- endometrial development continues
- negative feedback: no more LH and FSH or follicular development
LH levels decrease
- corpus luteum starts to degrade
- Eand P levels go down
- decrease inhibition of everything makes cycle start again
- corpus albicans
When is the estrogen peak vs the progesterone peak?
Estorgen at ovulation (causes LH surge)
Progestorone during luteal phase
Uterine Cycle Menstral Phase
-days, definition, and hormones
- Days 1-5
- Shedding of stratum functionalis: blood vessels constrict, dilate, and bleed
- E and P are low and corpus luteum is non-functional –> GnRH, FSH, and LH are released bc no inhibition
Proliferation phase
- Days 6-14
- Estrogen is rising due to follicular development from gonadotropins
- stratum functionalis thickens with glands and blood vessels
- cervical mucus becomes less viscous
Secretory phase
days 15-28
- E+P are high due to corpus luteum secretions
- further development of stratum functionalis
- cervical plug (mucus) –> blocks sperm and others entry –> protect possible implanted embryo
- Inhibit FSH and LH so corpus luteum degenerates and stratum functionalis isn’t maintained
body temp fun fact
body temp increases at ovulation
Estrogen
- oogenesis, follicular development, regulation of uterine cycle
- anabolic effects on female reproductive organs
- secondary sex characteristice (breast dvlpmnt, fat deposits, pelvic widening)
- growth spurt at puberty
- closure of epiphyseal plate
- calcium deposition in skeletal tissue
- cholesterol maintainance
Progesterone
- regulation of uterine cycle
- changes in cervical mucus
During pregnancy:
- inhibits uterine motility
- breast development
Menarche
Amenorrhea
Oligomenorrhea
Menopause
- 1st period
- from low body fat –> leptin hormone and lipid blood levels stimulate GnRH
- can be bc of pathology, stress, nearing menopause
- no more ovarian follicles around age 50 –> low estrogen and progesterone
PMS and PMDD
-hormonal causes
Prementrual syndrome and premenstrual dysphoric disorder
- Greater decrease in progesterone in luteal phase
- dif in interaction b’t ovarian steroids and brain (serotinin is affected)
- high estrogen at ovulation makes you feel better
- during luteal phase, feel more negative as estrogen levels fall
- sometimes skills are affected
