06b: Endocrinology of Reproduction Flashcards by Nuna H

(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

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LH acts on (X) cells, in general. Specifically which cells of ovary/testes?

X = interstitial (steroidogenic)

Leydig and theca cells

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FSH acts on (X) cells, in general. Specifically which cells of ovary/testes?

X = follicular

Sertoli and granulosa cells

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T/F: hCG is functionally equivalent to FSH and LH.

False - functionally equivalent to LH (although all three share common alpha subunit)

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(FSH/LH/hCG) act via AC, cAMP, PKA signaling.

All three (as well as TSH) - remember, share alpha subunit

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Estrogens: E1 is (X), E2 is (Y), and E3 is (Z).

X = estrone
Y = estradiol
Z = estriol

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Estrogen precursors are made by (X) cells and converted to final products in (Y) cells of ovary.

X = theca
Y = granulosa

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FSH (promotes/inhibits) production of estrogens by its action of (X) cells in ovary.

Promotes;

X = granulosa

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E(1/2/3) is a fetal (X) product..

E3 (estriol);

X = adrenal/liver-placental

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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

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Both E(1/2/3) and P have which effect on GnRH?

E2 and P;

Inhibit GnRH release

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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

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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

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Progesterone binds (X) in plasma.

Albumin and CBG (corticosteroid BG)

In 4:1 ratio

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T/F: Testosterone levels in seminiferous tubules is about equal to that in serum.

False - 200x greater

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(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

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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

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T/F: Inhibins are sex hormones.

False - peptide hormones

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What defines genetic sex?

Karyotype (XX or XY)

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What defines gonadal sex?

Internal genitalia (testis/ovary)

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What defines phenotypic sex?

Genital ducts, external genitalia, secondary sex characteristics

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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

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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

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XXX karyotype is (X) syndrome. List some characteristics of this individual.

X = Triple X

Female showing no unusual abnormalities

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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.

1. Thelarche (breast development) 2. Pubarche (axillary/pubic hair) 3. 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.

1. Capacitation 2. Hyperactivation (chemotactic agent from egg excites sperm) 3. 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 1. Placental progest. 2. Fetal/placental E2/E3 3. 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