Reproductive Lecture 4

Question 1

What drug results in an unusually high FSH/LH/testosterone?

Answer 1

clomiphene

Question 2

Define primary amenorrhea

Answer 2

absence of menses by age 17

causes: Turner’s, complete androgen resistance, hormonal disorders

Question 3

Define secondary amenorrhea

Answer 3

cessation of menstruation for longer than 6 months

causes: pregnancy, lactation

Question 4

What is galactorrhea?

Answer 4

inappropriate milk production in someone who is not lactating (can be caused by prolactinomas)

Question 5

Define oligomenorrhea

Answer 5

infrequent periods (cycle length >35 days)

causes: changes in CNS mechanisms that regulate GnRH release

Question 6

Define dysmenorrehea

Answer 6

painful menses due to uterine contractions (prostaglandin synthesis promoted by E2)

Question 7

Painful periods are due to which hormone?

Answer 7

prostaglandins

Question 8

What are some causes of hirsutism (excessive hair growth)

Answer 8

excessive androgen production by adrenals

Question 9

What differentiates hirsutism from virilization?

Answer 9

virilization includes more evidence of androgen stimulation like clitoral hypertrophy, deepening voice, balding

Question 10

What is PMS?

Answer 10

Premenstrual syndrome

Question 11

What is PCOS?

Answer 11

polycystic ovarian syndrome

root cause: insulin resistance, obesity

Question 12

How is PCOS related to insulin?

Answer 12

high insulin stimulates androgen production (leading to infertility) and increased conversion to estrogens (weight gain)

Question 13

What is the cause of the cysts in PCOS?

Answer 13

follicles degenerate into cysts, ovaries get really big

Question 14

What are some symptoms of PCOS?

Answer 14

• sleep apnea
• menstrual irregularity
• obesity/acne
• hirsutism

Question 15

What are treatments for PCOS?

Answer 15

metformin (can restore fertility)

Clomiphene (feedback on HPT axis)

Question 16

Is fetal age the same as gestational age?

Answer 16

NO, fetal age is 2 weeks less than gestational age (which is calculated from first day of last menstruation)

Question 17

When is the best chance for fertilization?

Answer 17

24 hours post-ovulation (48-72 hours post coitus for sperm)

Question 18

What is the acrosomal reaction?

Answer 18

release of proteolytic enzymes that disperse granulosa cells and permit sperm attachment to ZONA PELLUCIDA

Question 19

How are the enzyme rich contents of the acrosome released?

Answer 19

spermatozoan has receptors for glycoprotein (ZP3) so binding causes inreased IP3 leading to increased Ca++ which fuses inner and outer membranes

Question 20

What is the first exocytosis step of fertilization?

Answer 20

1) exocytosis of spermatozoan internal membrane contents

Question 21

Name the steps of fertilization

Answer 21

1) binding of sperm to zona pellucida
2) acrosomal reaction
3) penetration thru zona pellucida
4) fusion of plasma membrane
5) sperm nucleus enters egg cytoplasm

Question 22

What is the second exocytosis event of fertilization?

Answer 22

release of oocyte’s internal vesicles (harden glycoproteins of zona pellucida preventing polyspermy)

Question 23

Why is the Ca++ increase so important upon fertilization?

Answer 23

1) allows both exocytosis events

2) triggers completion of second meiotic division

Question 24

How long do sperm retain fertilizing capacity?

Answer 24

24-48 hours

Question 25

What percentage of sperm make it to the oviduct? ampulla?

Answer 25

0.1% to oviduct | a few hundred to the ampulla

Question 26

Does the vagina make sperm transport easier or harder?

Answer 26

easier (decreased acidity, increased cGMP to increase velocity and direction of sperm) contraction of ampulla wall to promote random interaction of sperm and ovum

Question 27

For how long does the blastocyst traverse the oviduct?

Answer 27

3 days

Question 28

What determines the timing of blastocyst entry into the uterus?

Answer 28

estrogen/progesterone balance estrogen constricts isthmus, barring passage of embryo to uterus to allow time for endometrial development progesterone promotes myometrium relaxation and transport of blastocyst to uterus

Question 29

What are the 3 successive processes of implantation?

Answer 29

1) adhesion 2) penetration 3) invasion

Question 30

What is the implantation failure rate?

Answer 30

70%

Question 31

What important cytokine increases integrins in endometrial cells (promoting implantation)?

Answer 31

IL-1

Question 32

What does osteopontin do/

Answer 32

binds integrins of both endometrium and blastocyst

Question 33

The egg hatches when ____________________

Answer 33

the zona pellucida dissolves

Question 34

What do stromal cells do?

Answer 34

form decidua and secrete nutrients (becomes barrier and endocrine organ later)

Question 35

Describe the burrowing and intermingling of endometrial cells and the egg

Answer 35

microvilli of trophoblasts interdigitate with endometrial cells then burrow under epithelial cells

Question 36

What hormone promotes the formation of the decidua from stromal cells?

Answer 36

progesterone

Question 37

What is the source of nutrients for the egg until vasculature can be established?

Answer 37

decidua

Question 38

What is invasion?

Answer 38

balance between decidual cells (defense) and trophoblast migration (offense) to prevent from burrowing too deeply

Question 39

What do trophoblasts secrete to help with burrowing? (and is blocked by decidual cells)

Answer 39

matrix metalloproteinases (MMP)

Question 40

What 2 things do trophoblasts differentiate into?

Answer 40

1) syncytiotrophoblasts | 2) cytotrophoblasts

Question 41

What are syncytiotrophoblasts?

Answer 41

mass without ell boundaries, extend between uterine epithelial cells

Question 42

What do syncytiotrophoblasts secrete?

Answer 42

TNF

Question 43

What do Cytotrophoblasts serete?

Answer 43

CRH and TRH | somatostatin

Question 44

Which of the two (syn or cyto) are responsible for most endocrine functions?

Answer 44

syncytiotrophoblasts

Question 45

What are 4 main functions of the placenta?

Answer 45

1) Gut (supplies nutrients) 2) Lung (gas exchange) 3) Kidney (fluid volume and waste disposal) 4) Endocrine gland

Question 46

How are nutrients transported to fetus?

Answer 46

diffusion of facilitate diffusion oxygen diffuses down conc gradietn (fetal Hb has higher affinity for O2 than adult)

Question 47

How is CO2 transferred from fetal to maternal blood to be exhaled?

Answer 47

CO2: pCO2 in fetal blood is 2-3mmHg higher than maternal blood so it can diffuse down that gradient

Question 48

What is hCG and what other hormone is it similar to?

Answer 48

secreted by fertilized baby (can be detected 9 days post conception) made by syn under control of GnRH from cyto similar to LH (rescues the luteum and stimulates secretion of progesterone and estradiol)

Question 49

What effect does hCG have on LH and FSH?

Answer 49

prevents it (otherwise would stimulate next cohort of follicles to develop) complemented by inhibin

Question 50

What other hormone is produced by sync that is structurally similar to GH?

Answer 50

Human placental lactogen (HPL) aka Human Chorionic Somatomammotrophin (HCS)

Question 51

What does HPL do?

Answer 51

in response to hypoglycemia, it stimulate lipolysis and has anti-insulin actions on maternal carb metabolism (increases plasma glucose and FFAs to maintain continuous flow of nutrients to baby)