06b: Endocrinology of Reproduction Flashcards
(Constant/pulsatile) levels of GnRH will decrease LH and FSH levels. Normally, GnRH is released in (constant/pulsatile) fashion.
Constant (down-regulation of GnRH receptors on gonadotrope);
Pulsatile
LH acts on (X) cells, in general. Specifically which cells of ovary/testes?
X = interstitial (steroidogenic)
Leydig and theca cells
FSH acts on (X) cells, in general. Specifically which cells of ovary/testes?
X = follicular
Sertoli and granulosa cells
T/F: hCG is functionally equivalent to FSH and LH.
False - functionally equivalent to LH (although all three share common alpha subunit)
(FSH/LH/hCG) act via AC, cAMP, PKA signaling.
All three (as well as TSH) - remember, share alpha subunit
Estrogens: E1 is (X), E2 is (Y), and E3 is (Z).
X = estrone Y = estradiol Z = estriol
Estrogen precursors are made by (X) cells and converted to final products in (Y) cells of ovary.
X = theca Y = granulosa
FSH (promotes/inhibits) production of estrogens by its action of (X) cells in ovary.
Promotes;
X = granulosa
E(1/2/3) is a fetal (X) product..
E3 (estriol);
X = adrenal/liver-placental
Early in menstrual cycle, moderate, steady levels of (X) hormone (stimulate/inhibit) (Y) hormone. But its sudden rise has opposite effect.
X = E
Inhibit
Y = LH
Both E(1/2/3) and P have which effect on GnRH?
E2 and P;
Inhibit GnRH release
In plasma, about (X)% of sex steroids are bound. What are the two main binding proteins for testosterone and E(1/2/3) in males?
X = 98
E2;
- GBG (gonadal steroid BG)
- Albumin
In males, testosterone is primarily bound to (X) in plasma and E2 primarily bound to (Y).
X = GBG (2/3) Y = Albumin (2/3)
The other 1/3 of each bound to the second binding protein
Progesterone binds (X) in plasma.
Albumin and CBG (corticosteroid BG)
In 4:1 ratio
T/F: Testosterone levels in seminiferous tubules is about equal to that in serum.
False - 200x greater
(FSH/LH) stimulates inhibin production by (X) cells. Inhibins act to (increase/decrease) (Y) release from pituitary.
FSH;
X = Sertoli and granulosa
Decrease;
Y = FSH
Inhibin (A/B) is produced in the male and in (X) phase in the female. Inhibin (A/B) is characteristic of (Y) phase in F.
B;
X = follicular
A;
Y = luteal
T/F: Inhibins are sex hormones.
False - peptide hormones
What defines genetic sex?
Karyotype (XX or XY)
What defines gonadal sex?
Internal genitalia (testis/ovary)
What defines phenotypic sex?
Genital ducts, external genitalia, secondary sex characteristics
XYY karyotype is (X) syndrome. List some characteristics of this individual.
X = Jacobs or “super male”
Seemingly normal male; potentially has excess acne, tall, aggressive
XXY karyotype is (X) syndrome. List some characteristics of this individual.
X = Klinefelter’s
- Male genitalia
- High FSH, LH, E2, but low T
- Sterile, feminine, mental retardation
XXX karyotype is (X) syndrome. List some characteristics of this individual.
X = Triple X
Female showing no unusual abnormalities
In males, (X) supports differentiation of Wolffian ducts to:
X = testosterone (from Leydig cells)
Epididymis, ductus deferens, seminal vesicle, ejaculatory duct
In males, (X) induces development of prostate as well as:
X = (Testosterone via) DHT
Urethra, penis, scrotum
In the (start/end) of (X) trimester, male T synthesized at near-adult levels. Why?
End;
X = first
Differentiation of internal and external genitalia
After birth, T level remains quite (low/high) in male until (X). “Resetting the gonadostat” involves (increase/decrease) in hypothalamus sensitivity to (Y).
Low;
X = puberty
Decrease;
Y = T inhibition
T/F: T levels reach maximum at puberty.
False - in mid/late 20s (then fall gradually)
List the three defining features of female puberty, in order of appearance.
- Thelarche (breast development)
- Pubarche (axillary/pubic hair)
- Menarche (first menstrual period)
Post-menopausal (FSH/LH/E/P) levels are high due to (X) lack of ability to produce adequate (Y).
FSH and LH
X = ovary
Y = E and inhibin
(X) hormones are responsible for early stages of pubic/axillary hair growth.
X = adrenal androgens
Testosterone inhibits which hypo/pituitary hormones?
LH and GnRH
Adult sex drive (libido) in M due to (X) hormone and F due to (Y) hormone.
X = Y = testosterone
Testosterone (increase/decreases) erythropoeisis and (increase/decreases) cholesterol levels.
Increases both
Passage through epididymis takes sperm how long?
about 12 days
T/F: F has most number of oocytes at birth.
False - at 20 wk gestation (6-7 million) and reduced at birth (1-2 million)
Menstrual cycle: progesterone secretion/rise is coming from (X).
X = corpus lutem
Thus, progesterone levels only start rising after ovulation
During (X) stage of ovulation, high Inhibin A secretion has which function?
X = luteal
Inhibit FSH (don’t want no mo’ oocytes!)
The “follicular” phase of menstrual cycle encompasses which range of day(s)? Which stage(s) correspond(s) to this phase in uterine cycle?
1-14;
Menstrual and proliferative phases of uterine cycle
As soon as ovulation occurs, (X) uterine phase and (Y) ovarian phase begin.
X = secretory Y = luteal
F basal body T increases in (X) ovarian phase, under influence of (Y) hormone.
X = luteal Y = progesterone
Thinning of cervical mucous occurs due to (high/low) levels of (X) hormone.
High
X = estradiol
Ovarian hormones: what’s the main form of estrogen released by (X) cells.
X = granulosa
17-b-estradiol
Estrogen acts on liver to (increase/decrease) (HDL/LDL) synthesis.
Increase HDL and decrease LDL
Progesterone has (X) effect on breast development and (Y) effect on cervix.
X = stimulates glandular growth Y = mucous thickening
Preventing pre-term delivery involves strong (stimulation/inhibition) of (X) contraction. Which hormone is key player in this?
Inhibition;
X = myometrial
Progesterone
At birth, the pool of (primary oocytes/secondary oocytes/oogonia) are (1/2)n(1/2)x.
Primary oocytes;
2n2x (arrested in prophase I)
Ovary: Rising (X) levels causes (increase/decrease) in (Y) levels. This is what prompts one follicle to become dominant, while the others undergo atresia.
X = Inhibin B
Decrease (inhibition);
Y = FSH
There’s a positive feedback look in (X) phase of ovulation. Which hormones/cells are involved?
X = late follicular
Estrogen-induced follicular cell growth results in rapidly rising estrogen levels; also increases GnRH receptors, so more LH production
T/F: Declining levels of estrogen in proliferative phase induces progesterone receptors to appear on endo and myometrial cells.
False - rising estrogen levels
T/F: It’s recommended to have long abstinence periods to save up sperm/ejaculate and increase chance of conception.
False - long abstinence periods associated with higher sperm counts, but lower motility
How often, after menstrual period, should couple aim to have intercourse to increase chances of conception?
Every day or every other day
List the three changes sperm undergoes in F reproductive tract for successful fertilization.
- Capacitation
- Hyperactivation (chemotactic agent from egg excites sperm)
- Acrosome Rxn
Acrosome reaction occurs when sperm contacts (X). What’s the function of this step in fertilization?
X = zona pellucida
Release of lytic enzymes from acrosome, required for penetration
Pinopodes are “embryo landing sites” that are expressed in higher amounts in response to (X) hormone.
X = progesterone
Post-fertilization: (X) form finger-like projections called (Y) into the endometrium. This allows development of extensive (Z).
X = syncytiotrophoblasts Y = chorionic villi Z = capillaries (linked to embryo circulatory system)
Diagnosis of pregnancy made by (urine/blood/stool) testing of (X). Where does (X) come from anyway?
Urine or blood;
X = hCG
Embryo trophoblast cells (immediately following invasion into endometrium)
hCG secretion starts (X) days/weeks/months post-fertilization. And gestational sac seen on ultrasound by (Y) days/weeks/months.
X = 7 days Y = 5 weeks
T/F: hCG spikes in first month of pregnancy and remains elevated until about 3rd trimester.
False - peaks around 2 mo GA, then falls rapidly to low, near-constant level
The luteo-placental transition occurs at (X) gestational age. List the three key hormones that rise consistently, starting at this time.
X = 6-10 weeks
- Placental progest.
- Fetal/placental E2/E3
- Placental lactogen
Women (should/shouldn’t) be lactating during pregnancy, due to action of (X) hormone.
Shouldn’t;
X = progesterone (inhibits milk production)
RU-486 (mifepristone) is an abortion drug. It acts as (stimulator/inhibitor) of (X) and is administered with (Y).
(Non-activating) competitive inhibitor
X = progesterone
Y = prostaglandin
Thus causes uterine contraction during pregnancy
Placental lactogen is similar to (X) hormone. What are its effects on CHO, fat, protein?
X = GH
CHO: promotes high glucose level (nourish fetus)
Fat: mobilizes FA for E
Protein: maintains positive balance
T/F: Placental lactogen induces gestational diabetes.
True- diabetogenic
Current hypotheses about triggers for birth: increase in (X) and/or decrease in (Y).
X = fetal adrenal activity (high DHEA, high Estrogen synthesis;
Y = progesterone efficacy (more contractile uterus)
Maternal pituitary volume (increases/decreases) in line with gestational age.
Increases
Pregnancy: plasma volume (increases/decreases) and (proportionate/disproportionate) (increase/decrease) in RBC mass.
Increase in both, but disproportionate (less RBC increase); relative ANEMIA of pregnancy
Pregnancy: (hypo/hyper)-coagulable state.
Hyper-coagulable
Pregnancy: (increase/decrease) contraction of gastric/bowel motility with (increase/decrease) reflux and (diarrhea/constipation).
Decrease;
Increase;
Constipation
Pregnancy: (increase/decrease) CO, HR, TPR.
Increase CO and HR; decrease TPR (and BP)
T/F: Increase GFR during pregnancy contributes to high urine output.
True - along with increase pressure on bladder
T/F: Prior to pregnancy, no alveoli (only ducts) exist in breast.
False - ducts with few alveoli
