Lecture 15 recap

Question 1

Decreased blood flow to legs in pregnancy increases risk of what? Why?

Answer 1

DVT; slower blood flow causes clotting

Question 2

What increases renal blood flow?

Answer 2

Progesterone

Question 4

Is Naegele’s rule for dating pregnancy accurate?

Answer 4

No; incredibly inaccurate- there are apps for this these days

Question 5

The _________________is the site of fertilization

Answer 5

Ampulla

Question 6

[Fertilization]
1) Define capacitation
2) What triggers it?

Answer 6

1) Final maturation of sperm
2) Acidic environment removes glycoproteins

Question 7

[Fertilization]
1) Sperm binds to what part of the egg?
2) What ion does this increase? What does this lead to?

Answer 7

1) Zona Pellucida
2) Ca2+; acrosomal reaction
(acrosome fuses w. plasma membrane)

Question 8

1) Following implantation of the blastocyst in the uterine wall, the _______________ forms.
2) What form and fill with blood to eventually develop into this structure?

Answer 8

1) placenta
2) Lacunae [eventually become a placenta]

Question 9

What 2 tissues of the endometrium develops into the placenta?

Answer 9

Trophoblastic and decidual

Question 10

[Placenta development]
What layer of the chorion continues to expand? What does this eventually erode, and what does this cause?

Answer 10

Trophoblastic layer; maternal capillary walls, leaking maternal blood to fill the cavities

Question 11

List 2 hormones made by the placenta and describe when each begins to rise and for how long

Answer 11

1) hCG: human chorionic gonadotropin
-detectable 6-8 days post-fertilization [doubles every 2-3 d until 15 wks]
2) hPL: Human placental lactogen
-rises in wk 3 [until term]

Question 12

1) What hormone extends life of the corpus luteum?
2) What does this also stimulate?
3) When is this hormone detectible?
4) When does it increase and at what rate?

Answer 12

1) hCG
2) luteal steroidogenesis
3) 6-8 days after fertilization
4) Every 2-3 days until about 15 weeks

Question 13

1) What hormone is similar to GH and PRL?
2) When does it rise in pregnancy?
3) What does it regulate? By promoting what?
4) What condition can it lead to?

Answer 13

1) hPL
2) During the 3rd week until term
3) Fuel availability by promoting maternal insulin resistance
4) Gestational diabetes

Question 14

[Placental exchange:]
What does estrogen increase and enhance in both the mother and fetus?

Answer 14

Increases size of uterus and blood flow, enhance fetal organ development, increase breast tissue

Question 15

1) Progesterone produced by the placenta enters the ____________ circulation.
2) Some gets converted to ____________.
3) What effect does this have?

Answer 15

1) maternal
2) DHEAS
3) Increases water solubility and aids in transportation

Question 16

Estrogen stimulates the renin-angiotensin system to raise _____________ levels and promote ____________ reabsorption, thus, water _____________.

Answer 16

aldosterone; sodium; retention

Question 17

What are the only two physiologic factors discussed to decrease during pregnancy?

Answer 17

Peripheral resistance and functional residual capacity

Question 18

[Maternal Adaptation]:
1) There’s a physiological __[increase/ decrease]__ in systemic BP during pregnancy​.
2) This should not to be mistaken for ____________.​

Answer 18

1) decrease
2) hypotension

Question 19

1) What type of compression can potentially explain low BP in pregnancy if pt is experiencing symptoms? When and in what position?
2) Why does it happen?
3) List the chain of events

Answer 19

1) IVC compression; > 20 weeks gestation; supine position ​​
2) Growing uterus is compressing on IVC and/or aorta can threaten perfusion to body and/or placenta​
3) Less venous return > less CO > BP falls > dizziness, lightheadedness, headache, presyncope > syncope

Question 20

During pregnancy, a woman’s blood clots more easily to lessen blood loss during labor and delivery and protect from hemorrhage; how?

Answer 20

Coagulability increases:
1) Increase in clotting factors (7, 8, 9, 10) and fibrinogen.
2) Fibrinolytic activity decreases simultaneously.

Question 21

1) What two things abt pregnancy alter pulmonary funct.?
2) What sensitivity does the rise in progesterone [in pregnancy] enhance?
2B) What does this increase?

Answer 21

1) Progesterone & the enlarging uterus
2) Brain respiratory center to carbon dioxide
2B) Tidal volume

Question 22

List what happens to these in pregnancy:
1) Airway tone
2) Minute ventilation
3) PCO2
4) Arterial PO2
5) pH
[all due to progesterone and enlarging uterus]

Answer 22

1) Relaxes; bronchodilation
2) Increases: 30%
3) Decrease
4) Increase
5) Slight respiratory alkalosis

Question 23

1) As uterus enlarges the diaphragm is elevated by how much?
2) What does this cause?
3) What two vitals does this reduce?

Answer 23

1) 4-5 cm
2) Early closure of smaller airways
3) Functional residual capacity and expiratory reserve volume (FRC & ERV)

Question 24

Why does constipation occur in pregnancy? Explain

Answer 24

Progesterone = vasodilator
-Decreases transmit time in intestines > colonic relaxation > hard stools > constipation

Question 25

1) GERD (heartburn) occurs in pregnancy bc of what two factors? 2) What lifestyle changes can help? 3) What severe GI condition can occur in pregnancy?

Answer 25

1) LES (lower esophageal sphincter) relaxation + compression of stomach by gravid uterus = reflux 2) Avoid caffeine, spicy foods, nicotine -TUMS are safe during pregnancy 3) Gallbladder disease

Question 26

Endocrine function and maternal metabolism change to support fetal growth by increasing what 4 hormones?

Answer 26

1) PRL 2) Cortisol 3) CRH 4) Insulin

Question 27

Of the 4 hormones discussed that increase in pregnancy: 1) Which involves breastfeeding? 2) Which is a stimulant for labor? 3) Which maintain blood sugar levels (risk of gestational DM)? 4) Which contributes to fetal lung development? 5) Which cause stretch marks and contr. to insulin resistance?

Answer 27

1) Prolactin; “pro-lactation”​ 2) Corticotropin releasing hormone (CRH)​ 3) Insulin 4) Cortisol 5) Cortisol

Question 28

__________ activates milk ejection; aka the "let down” reflex

Answer 28

Oxytocin

Question 29

1) Parturition (birth) is on average _________ days+/- 14 days from fertilization 2) What hormone keeps the uterus inactive? What expression is reduced? 3) Is this reduction/ block overridden or not?

Answer 29

1) 270 2) Progesterone; estrogen receptors expression (progesterone block) 3) Fetal growth stimulates more receptors, overriding block

Question 30

Placental **estrogen** reaches a peak which prepares uterus and cervix for labor and delivery; this includes: 1) ___________ inserted into gap junctions allow the uterine smooth muscles cells to contract as a single unit 2) Increased concentration of myometrial _____________ receptors; ____________ **ultimately initiates labor** 3) Local prostaglandins degrade local __________ fibers and also increase responsiveness to ___________.

Answer 30

1) Connexons 2) oxytocin; oxytocin 3) collagen; oxytocin

Question 31

What ultimately initiates labor?

Answer 31

Oxytocin

Question 32

Parturition's positive feedback cycle of oxytocin (pre-delivery): 1) What first triggers this cycle? 2) What happens when uterine contractions become more powerful?

Answer 32

1) Pressure of the fetus against the cervix triggers oxytocin from posterior pituitary 2) More oxytocin is released

Question 33

Parturition's positive feedback cycle of oxytocin (post- delivery): 1) What causes the secession of this cycle? Why? 2) What two hormones are gone? 3) What hormone inhibitory effect on prolactin is then withdrawn? What does this do?

Answer 33

1) Baby and placenta are delivered, pressure against cervix ceases 2) Placental estrogen and progesterone 3) Estrogen; initiates lactation