Repro_Physiology Flashcards
What are the normal functions of LH & FSH in males?
Pulsatile secretion of GnRH from the hypothalamus stimulates secretion of LH & FSH from the anterior pituitary
LH:
- Stimulates release of Testosterone from Leydig cells in the interstitium of the testicles
(Testosterone produces neg feedback of GnRH & LH)
FSH:
- Stimulates release of Inhibin B from the Sertoli cells in the seminiferous tubules of the testicles
(Inhibin B produces neg feedback of FSH)
- Stimulates release of Androgen-Binding Globulin from Sertoli cells, which maintains high local concentration of Testosterone in the testicles. High local levels of FSH & Testosterone are necessary for spermatogenesis
hCG is structurally similar to what other 3 hormones?
TSH, FSH, & LH
(it can bind their receptors w/ some affinity if elevated, like in teratomas –> tumors found in ovaries or testes that also cause hyperthyroid-related symptoms due to hCG binding TSH-receptors)
The nerves, arteries, veins, & lymphatics of the ovaries are all delivered via the ______ ligament of the ovary.
suspensory
Name the 3 forms of Estrogen, where they’re each produced, & their order of potency.
Estradiol (Ovary) > Estrone (adipose tissue) > Estriol (Placenta)
4 sources of Progesterone?
Corpus Luteum, Placenta, Adrenal cortex, Testes
What is the effect pulsatile GnRH has (via FSH & LH) on the Granulosa & Theca cells of the ovaries?
Pulsatile GnRH secretion causes LH & FSH release
LH → Theca cells
- Conversion of Cholesterol → Androstenedione
- Enzyme = Desmolase
FSH → Granulosa cells
- Conversion of Androstenedione → Estradiol
- Enzyme = Aromatase
What hormone is responsible for the maintenance of pregnancy?
Progesterone
Elevation of _____ is indicative of ovulation.
progesterone
What hormone is responsible for the production of thick cervical mucus, which inhibits sperm entry into the uterus?
Progesterone
Progesterone - effect on gonadotropins (LH, FSH)?
Inhibition
Progesterone - effect on myometrium (uterine smooth muscle)?
Relaxation (preventing contractions)
Progesterone - effect on estrogen receptors?
↓ estrogen receptor expressivity
Progesterone - effect on endometrium?
Stimulation of endometrial glandular secretions & spinal artery development
Estrogen - effect on endometrium?
Endometrial proliferation
Estrogen - effect on myometrium (uterine smooth muscle)?
↑ myometrial excitability
What hormone is responsible for the development of female genitalia, breasts, & fat distribution?
Estrogen
Estrogen - effect on Follicle?
↑ growth of follicle
Estrogen - effect on gonadotropins (LH, FSH)?
Feedback inhibition of LH & FSH, until LH surge
- Upregulation of estrogen, LH, & progesterone receptors
Estrogen - effect on estrogen receptors?
Upregulation of estrogen, LH, & progesterone receptors
Estrogen - effect on SHBG, HDL, & LDL?
↑ SHBG & HDL
↓ LDL
Progesterone - effect on body temperature?
↑ body temperature
Name the 3 androgens in order of their potency.
DHT > Testosterone > Androstenedione
DHT - major “early” & “late” functions?
Early - Differentiation of penis, scrotum, prostate
Late - Prostate growth, balding, sebaceous gland activity
Describe the pathway of how exogenous Testosterone affects sperm count.
Exogenous testosterone → inhibition of hypothalamic--pituitary--gonadal axis → ↓ intratesticular testosterone → ↓ testicular size → ↓ azoospermia
Azoospermia = No measurable level of sperm in semen
Hormone responsible for deepening of the male voice?
Testosterone
Hormone responsible for differentiation of epididymis, vas deferens, seminal vesicles (internal genitalia, except prostate)?
Testosterone
Hormone responsible for differentiation of prostate?
DHT
Hormone responsible for differentiation of penis?
DHT
Hormone responsible for differentiation of scrotum?
DHT
Hormone responsible for growth spurt?
Testosterone
Hormone responsible for closure of the epiphyseal plates?
Testosterone
Enzyme responsible for conversion of Testosterone & Androstenedione → Estrogen?
Aromatase
Enzyme responsible for conversion of Testosterone → DHT?
5 α-reductase
Menstrual Cycle:
__a__ phase can vary in length.
__b__ phase is usually a constant 14 days.
a) Follicular (proliferative)
b) Luteal (secretory)
Menstrual Cycle:
__a__ stimulates endometrial proliferation.
__b__ maintains endometrium to support implantation.
a) Estrogen
b) Progesterone
↓ __?__ → ↓ fertility
↓ progesterone → ↓ fertility
Define:
- Oligomenorrhea
- Polymenorrhea
Oligomenorrhea: >35-day cycle
Polymenorrhea: <21-day cycle
Define:
- Metrorrhagia
- Menometrorrhagia
Metrorrhagia = frequent but irregular menstruation
Menometrorrhagia = heavy, irregular menstruation @ irregular intervals
When are LH levels greater then FSH levels?
Only during the Luteal Surge.
FSH levels are higher during the majority of both the follicular & luteal phases.
__?__ surge stimulates LH release (surge), causing ovulation (rupture of the follicle)
Estrogen
What hormone causes the increase in body temperature during ovulation?
Progesterone
What is Mittelschmerz?
Blood from ruptured follicle or follicular enlargement causes peritoneal irritation that can mimic appendicitis
Primary Oocytes:
Meiosis I is arrested in _____ for years until Ovulation.
prOphase I
Secondary Oocytes:
Meiosis II is arrested in _____ until fertilization.
METaphase II
“an egg MET a sperm”
Where does fertilization most commonly occur?
When must this occur w/ respect to ovulation?
Upper end of fallopian tube (the ampulla)
Must occur w/in 1 day of ovulation
if not, the secondary oocyte degenerates
Implantation w/in the wall of the uterus occurs ____ days after fertilization
6 days
How soon after fertilization is hCG detectable to give a positive pregnancy test?
Detectable in blood 1 week after conception
Detectable in urine 2 weeks after conception
What is the best test to confirm menopause?
↑↑ FSH
(loss of negative feedback for FSH due to ↓estrogen)
**note: LH & GnRH also increase
Hormone necessary for spermatogenesis in males?
Testosterone
Hormone necessary for male sexual differentiation at Puberty (such as development of muscle mass & libido)?
Testosterone
Hormone responsible for Prostate growth in males?
DHT
Hormone primarily responsible for balding in males?
DHT
Hormone responsible for external male genitalia in the embryo (scrotum & penis)?
DHT
Hormone responsible for facial hair in males?
DHT
____ amplifies the effects of Testosterone due to a much higher affinity at the Testosterone receptors.
DHT
