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Flashcards in Parturition Deck (22):
1

stages of labor

1. latent - contraction with with slow cervical dilation

1. Active: contractionswith fast dilation

2. complete dilation until delivery

3. post delivery of fetus until placenta

4.one hour post-placenta. Constant myometrial contraction that limtis blood loss

2

in contraction, 

 

myosin is ___ 

ATP is ____

myosin is phosphorylated

ATP is hydrolyzed

3

actions of Progesterone in labor

inhbits intracellular Ca entry

inhibits relese from SR

membrane hyperpol via K channels

inhibits expression of contraction associated protein genes

levels are contant before and during labor

4

mechanism of premature ruprtre of membranes in preterm labor

apoptosis of cellular compontent of fetal membrane

matrix metalloproteinases play a role

4

tx post-partum hemorrhage

uterine massage

xytocin

prostaglnadins

ergot alkaloid

5

4 possible contributions to pre-term labor (categories only)

Uterine Distension

Meternal Fetal stress

Infection

premature rupture of membranes

6

mechanism of maternal fetal stress in preterm labor

premature rise in cortisol and estrogens induce labor phenotpye and stmiulate fetal adrenal c19 hormones

6

risk factors post-partum hemorrhage

preciptous labor OR prolonged

polyhydramnios
grand multiparity
large fetal weight
intrauterine infection
mutifetla gestation
retained placenta
uterine relaxation agents

7

sheehan syndrome =

hypovolemia from obsterical lood loss leads to pituiray infarct or necrosis 

lacation failure

hypoglycemia

life thretening hypotension from adrenal insufficiency

Possible lag time for symptom onset

8

window for pre-term labor

20-37wks

10

CAP proteins =

examples (4)

uterine stretch and estrogen upregulate proteins that initiate excitation and incresae frequency and amplittude of contractions

Gap junction protein connexin 43

Corticotropin releaseing hormone receprotr

oxytocin receptor

COX2

11

oxytocin increases ___ and ___ levels

prostaglandin and estrogen levels

12

actions of estrogen in labor

increases gap junctions between myometrial cells

increases oxytocin receptor and prostaglandin receptor expression 

13

uterine changes in pregnancy

increase in size (4-70g to 1200 grams

myometrial cells prolif early

myometiral cells hpertrophy in later half

gap junction sbetween myometrial cells increase

major increase in blood supply

14

possible triggers for labor cascade

fetal andrenal glands

increased maternal estrogens

increased prostaglnadins

increase in CAP

15

cut offs for post-partum hemorrhage

500ml for vaginal loss

1000ml for cesarean loss

16

process of uterine contractions

increae in intracellular Ca

Ca bind calmodulin

myosin light chain kinase activated

16

mechanism of uterine distension to preterm labor

CAP expression

CRH and estrogen increase

oxytocin release

Uterine activation

18

transition from quiescence phase to labor phase involves ____

shift from progesterone dominance to estrogen dominance

20

identifiable risk factors for pre-term labor

Infection + peridontal dieae

low pre-pregnancy weight, SES, ethnicity

cervical shortening > decreased uterine space

Genetics (HX and FHx)

Smoking

21

Rx to prevent preterm in patients with Hx or with shortened cerical length on ultrasound

progesterone

22

therapies for preterm labor (stop contractions) that rely on preventign intracellualr Ca influx

Magnesium

Beta 2 adrenergic agonists

Ca channel blockers

prostaglandin synthesis inhibitors