Theories of Labor Flashcards
Uterine muscle stretching, which results in release of
prostaglandins.
Pressure on the cervix, which stimulates the release of
oxytocin from the posterior pituitary
Oxytocin stimulation, which works together with prostaglandins to initiate
contractions.
Change in the ratio of estrogens to progesterone
(increasing estrogen in relation to progesterone stimulates uterine contractions).
which triggers contractions’ at a set point.
Placental age
which reduce progesterone formation and increase prostaglandin formation.
Rising fetal cortisol levels
labor begins before a fetus is mature
(preterm birth).
In others, labor is delayed until the fetus and the placenta have both passed beyond the optimal point for birth
(postterm birth).
- a hallow organ when stretched to capacity contract and empty
Uterine stretch theory
production of oxystosin from pesterior pituitary gland - contraction of the uterus
Oxytocin theory
progesterone inhibit uterine mortility. A devrease in progesterone - uterine contraction
Progesterone deprivation theory
Increase in prostaglandin synthesis- uterine contraction
Prostaglandin theory
Decrease in blood supply to the placenta - uterine contraction
theory of aging placenta
