Ovulation

Question 1

Why are birth control pills effective?

Answer 1

They control hormone levels, preventing ovulation and altering the endometrium.

Question 2

What is ovulation?

Answer 2

Release of an egg from the ovary every ~28 days.

Question 3

What prepares the uterus for implantation?

Answer 3

The menstrual cycle.

Question 4

Where do oocytes develop?

Answer 4

In follicles within the ovaries.

Question 5

What happens post-fertilization?

Answer 5

The embryo implants in the uterus ~1 week later.

Question 6

What happens during folliculogenesis?

Answer 6

Primordial follicles grow and prepare for ovulation.

Question 7

What causes the endometrium to thicken?

Answer 7

Estradiol.

Question 8

What happens if no implantation occurs?

Answer 8

Endometrium is shed as menses.

Question 9

What does estrogen do to endometrial cells?

Answer 9

Thickens lining and induces progesterone receptors.

Question 10

Progesterone’s effect on glands?

Answer 10

Makes glands tortuous and increases secretion.

Question 11

Phases of the ovulatory cycle?

Answer 11

Follicular and luteal.

Question 12

Phases of uterine cycle?

Answer 12

Menses, proliferative, and secretory.

Question 13

What forms the corpus luteum?

Answer 13

Granulosa cells post-ovulation.

Question 14

What causes menses?

Answer 14

Drop in estrogen and progesterone.

Question 15

What hormones inhibit LH and FSH?

Answer 15

Estradiol, progesterone, and inhibin.

Question 16

FSH acts on which cells?

Answer 16

Granulosa cells.

Question 17

LH acts on?

Answer 17

Theca cells.

Question 18

What does hCG do if pregnancy occurs?

Answer 18

Maintains corpus luteum and progesterone production.

Question 19

What starts the follicular phase?

Answer 19

Drop in estrogen/progesterone → rise in FSH.

Question 20

When does estrogen peak?

Answer 20

Day 12–13, triggering LH surge and ovulation.

Question 21

What causes follicle rupture?

Answer 21

LH surge → proteolytic enzymes break the wall.

Question 22

Where does the oocyte go post-ovulation?

Answer 22

Into the uterine tube.

Question 23

What secretes progesterone in this luteal phase?

Answer 23

Corpus luteum.

Question 24

What happens if no fertilization?

Answer 24

Corpus luteum atrophies → hormone levels drop → menses.

Question 25

Why does the endometrium shed?

Answer 25

Lack of hormonal support from estrogen and progesterone.

Question 26

What hormone drives endometrial growth?

Answer 26

Estrogen.

Question 27

What else does estrogen do?

Answer 27

Induces progesterone receptors.

Question 28

What transforms the endometrium for implantation?

Answer 28

Progesterone.

Question 29

What happens without fertilization?

Answer 29

Corpus luteum decays → hormones fall → menstruation begins.

Question 30

Why are multiple follicles needed for IVF?

Answer 30

To increase chances of collecting mature eggs.

Question 31

How is this achieved?

Answer 31

By giving high levels of gonadotropins.

Question 32

When is pregnancy full term?

Answer 32

At 39 weeks.

Question 33

Trimester breakdown?

Answer 33

1st: LMP to week 12; 2nd: 13–27; 3rd: 28–40.

Question 34

When does the placenta take over hormone production?

Answer 34

Around week 10.

Question 35

What causes morning sickness?

Answer 35

High β-hCG levels.

Question 36

Name three first trimester risks.

Answer 36

Ectopic pregnancy, congenital infections, spontaneous abortion.

Question 37

What is quickening?

Answer 37

First noticeable fetal movement (~20 weeks).

Question 38

Common complication?

Answer 38

Gestational diabetes.

Question 39

Common issues in the third trimester?

Answer 39

Preeclampsia, reflux, varicose veins.

Question 40

When are lungs typically mature?

Answer 40

By 36 weeks.

Question 41

Main functions of the placenta?

Answer 41

Nutrient/gas exchange, hormone secretion, immune modulation.

Question 42

Placental size at term?

Answer 42

About 8 inches in diameter and 1 inch thick.

Question 43

Hormones secreted by placenta?

Answer 43

Progesterone, estrogen, hCG, relaxin, placental lactogen, CRH.

Question 44

Function of human placental lactogen?

Answer 44

Alters maternal metabolism to favor fetal nutrition.

Question 45

How does CRH help labor?

Answer 45

Stimulates prostaglandins and DHEA, triggering contractions.

Question 46

What effect helps fetal oxygen uptake?

Answer 46

Haldane effect and Bohr effect.

Question 47

Why is fetal hemoglobin more efficient?

Answer 47

Higher O2 affinity than adult Hb.

Question 48

How does the placenta protect the fetus?

Answer 48

Uses atypical HLA-G and other strategies to reduce maternal immune attack.

Question 49

What does Fas ligand do?

Answer 49

Causes apoptosis of maternal T cells to protect fetus.

Question 50

How does IDO protect the fetus?

Answer 50

Breaks down tryptophan to inhibit maternal T cells.

Question 51

What antibody crosses the placenta?

Answer 51

IgG (provides passive immunity to fetus).