10.2 Mechanics of Parturition Flashcards
uterus must _____
- onset of parturition
contract
cervix must have the capacity to ___
- ripening & dissolution of cervical mucus plug
dilate
MATERNAL HORMONES
- Decreasing days
or hours before
Progesterone
as progesterone decreases then the uterus will now be
able to ______
contract
MATERNAL HORMONES
- Increasing days or weeks before
- Relaxes birth canal (specific function)
- Acts on uterine muscles to modulates & stimulates uterine contraction
Estrogen
MATERNAL HORMONES
a. Stimulates uterine contraction
b. Stimulates PGF2 alpha production
*produced by hypothalamus and released by posterior pituitary gland
Oxytocin
MATERNAL HORMONES
a. Luteolysis (lysis of corpus luteum)
b. Stimulates uterine contraction (by acting on
uterine muscles)
c. Dilation of cervix
PGF2 alpha
MATERNAL HORMONES
a. Relaxes cervix
b. Relaxes birth canal
c. Softening of pelvic
ligaments
Relaxin
only FETAL HORMONE
- initiates parturition
- synthesis of estrogen by adrenal gland
Cortisol
released by trophoblastic cells of the placenta
relaxin
stimulates production of estrogen– the change from progesterone to estrogen through the activation of enzyme needed
cortisol
MATERNAL HORMONES (5)
- Progesterone
- Estrogen
- Oxytocin
- PGF-2 alpha
- Relaxin
All maternal hormones act on uterine muscle to promote contraction except?
relaxin
during the late stage of pregnancy or gestation, the fetus would engage in the ____ _____, leading to stretching & irritation of the cervix
pelvic canal
sensory signals is transmitted thru hypothalamus particularly (2)
- PVN
- SON
The ____ neurons of the PVN and SON would be activated and these neurons would produce and release OXYTOCIN
oxytocinergic neurons
From the ______
pituitary gland, oxytocin would be released in the peripheral blood circulation and would act on the uterine muscles.
posterior
when oxytocin binds to the uterus it actually promotes the contraction of the _____ cells
myometrial cells
oxytocin also acts on the cells in the uterus to produce ______
PGF2 alpha
(2) involved in myometrial contraction needed for the expulsion of the FETUS and PLACENTA during parturition
- PGF-2 alpha
- estrogen
This engagement of fetus in cervical canal is what we call the _______ ___.
Ferguson’s reflex
At -5 or 5 days before parturition you would see that the fetal cortisol begins to _____ as it nears parturition.
increase
increase in fetal cortisol stimulates the enzymes in the dam (specifically in the adrenal gland) to _______ progesterone
level
decrease
This decrease in progesterone results in an _______ in estrogen production.
increase
Oxytocin secretion also starts days before parturition which acts on uterus causing production of _____ ____ near parturition
PGF2 alpha
