Pregnancy Parturition & Lactation - RM

Question 1

What is the purpose of follicular cells?

Answer 1

protect and nurture egg

Question 2

Where do sperm bind glycoproteins as the first step of fertilization?

Answer 2

zona pellucida

Question 3

What is the acrosomal reaction? What triggers it?

Answer 3

• triggered by rise in intracellular calcium from sperm binding glycoprotein
• leads to fusion of acrosome with sperm plasma membrane and release of hydrolytic enzymes in sperm

Question 4

What allows the sperm to penetrate the zona pellucida?

Answer 4

hydrolytic enzymes released dissolve zona pellucida and whip-like motion of tail pushes sperm forward

Question 5

What is the cortical reaction?

Answer 5

• exocytosis of granules that previously lay immediately beneath the egg’s plasma membrane
• enzymes released lead to hardening of zona pellucida to prevent entry of other sperm

Question 6

What 3 things does the rise in intracellular calcium trigger?

Answer 6

acrosomal reaction, cortical reactoin, expulsion of second polar body (completion of second round of meiosis)

Question 7

What is the product of the male and female pronuclei fusing called?

Answer 7

zygote

Question 8

What hormone regulates the one degree increase in basal body temperature at ovulation?

Answer 8

progesterone

Question 9

In what time frame after ovulation does fertilization have to occur to be successful?

Answer 9

within 24 hours

Question 10

How long does it take to optimize the uterus for nourishment for the blastocyst to implant?

Answer 10

around a week

Question 11

Why do you need the corpus luteum still in the 1st 8 weeks of pregnancy? What hormone does it produce?

Answer 11

• to sustain the blastocyst since the placenta hasn’t fully developed yet
• produces hCG, which substitutes for LH at this time since they are homologous and share receptors

Question 12

How does sperm make its way to ampulla of fallopian tube? (female contribution, male contribution)

Answer 12

• fallopian tube contraction in response to oxytocin released during orgasm
• fallopian tube contraction in response to prostaglandins in seminal fluid

Question 13

What produces hCG? What does hCG do in males?

Answer 13

synctiotrophoblasts in blastocyst

stimulates testes to produce testosterone

Question 14

What does early fetal nutrition? Later fetal nutrition?

Answer 14

early–endometrial lining

later–diffusion through placenta

Question 15

What hormones does the placenta supply?

Answer 15

steroid hormones (progesterone, estrone, estradiol, estriol), hCG, somatomammotropins (related to growth hormone and promotes mammary gland development)

Question 16

What indicates the normal development and health of placenta?

Answer 16

rapid rise in estriol

Question 17

What contribution from the fetus do you need to make estrogen in the placenta?

Answer 17

DHEA-S (androgen) from fetal adrenal and liver

Question 18

What is maternal response to pregnancy related to blood volume, MAP, CO, and alveolar ventilation?

Answer 18

blood volume–increases to meet increased demands
MAP–decreases due to vasodilation from steroid hormone and adaptive changes of kidney or remains around normal after rise in 3rd trimester
CO–increased primarily in 1st trimester from increased SV
Alveolar ventiliation–increased tidal volume from steroid’s effects on respiratory centers, decreased maternal arterial PCO2

Question 19

What can trigger parturition?

Answer 19

increased fetal production of cortisol
increased ratio of estrogen/progesterone
increased sensitivity to contractile stimulus

Question 20

What keeps the uterus quiet in most of pregnancy?

Answer 20

progesterone, relaxin

Question 21

What are Braxton Hicks contractions?

Answer 21

baby’s head stretches cervix, excites fundic contraction by release of oxytocin, contraction pushes baby’s head further down, stretches more, repeats (ouch)

Question 22

What initiates contractions? What sustains them?

Answer 22

prostaglandins initiates, oxytocin sustains

Question 23

What increases the number of oxytocin receptors on myometrial tissue during pregnancy?

Answer 23

estrogen

Question 24

What is the Ferguson reflex?

Answer 24

increase in oxytocin release in response to distension of cervix

Question 25

What produces relaxin? What does relaxin do?

Answer 25

produced by corpus luteum, placenta

increased production in labor may soften/dilate cervix

Question 26

What does Ru486 do?

Answer 26

inhibits progesterone to make uterus more contractile and cause abortion

Question 27

What two functions does oxytocin have? what is it released in response to?

Answer 27

milk letdown, uterine contractility

suckling

Question 28

What does prolactin do?

Answer 28

promotes and maintains milk synthesis

in response to suckling

Question 29

Why doesn’t prolactin start having an effect till after birth happens?

Answer 29

estrogen and progesterone from placenta inhibit it, once it is delivered, this inhibition is released and prolactin has effect

Question 30

What is the functional secretory unit of the breast?

Answer 30

alveolus

Question 31

What permissive hormone stimulates milk production besides prolactin?

Answer 31

cortisol

Question 32

How is colostrum different from milk?

Answer 32

lower volume, lower fat, higher antibodies