10.2 Mechanics of Parturition

Question 1

uterus must _____
- onset of parturition

Answer 1

contract

Question 2

cervix must have the capacity to ___

• ripening & dissolution of cervical mucus plug

Answer 2

dilate

Question 3

MATERNAL HORMONES

• Decreasing days
  or hours before

Answer 3

Progesterone

Question 4

as progesterone decreases then the uterus will now be
able to ______

Answer 4

contract

Question 5

MATERNAL HORMONES

• Increasing days or weeks before
• Relaxes birth canal (specific function)
• Acts on uterine muscles to modulates & stimulates uterine contraction

Answer 5

Estrogen

Question 6

MATERNAL HORMONES

a. Stimulates uterine contraction
b. Stimulates PGF2 alpha production

*produced by hypothalamus and released by posterior pituitary gland

Answer 6

Oxytocin

Question 7

MATERNAL HORMONES

a. Luteolysis (lysis of corpus luteum)
b. Stimulates uterine contraction (by acting on
uterine muscles)
c. Dilation of cervix

Answer 7

PGF2 alpha

Question 8

MATERNAL HORMONES

a. Relaxes cervix
b. Relaxes birth canal
c. Softening of pelvic
ligaments

Answer 8

Relaxin

Question 9

only FETAL HORMONE

• initiates parturition
• synthesis of estrogen by adrenal gland

Answer 9

Cortisol

Question 10

released by trophoblastic cells of the placenta

Answer 10

relaxin

Question 11

stimulates production of estrogen– the change from progesterone to estrogen through the activation of enzyme needed

Answer 11

cortisol

Question 12

MATERNAL HORMONES (5)

Answer 12

1. Progesterone
2. Estrogen
3. Oxytocin
4. PGF-2 alpha
5. Relaxin

Question 13

All maternal hormones act on uterine muscle to promote contraction except?

Answer 13

relaxin

Question 14

during the late stage of pregnancy or gestation, the fetus would engage in the ____ _____, leading to stretching & irritation of the cervix

Answer 14

pelvic canal

Question 15

sensory signals is transmitted thru hypothalamus particularly (2)

Answer 15

1. PVN
2. SON

Question 16

The ____ neurons of the PVN and SON would be activated and these neurons would produce and release OXYTOCIN

Answer 16

oxytocinergic neurons

Question 17

From the ______
pituitary gland, oxytocin would be released in the peripheral blood circulation and would act on the uterine muscles.

Answer 17

posterior

Question 18

when oxytocin binds to the uterus it actually promotes the contraction of the _____ cells

Answer 18

myometrial cells

Question 19

oxytocin also acts on the cells in the uterus to produce ______

Answer 19

PGF2 alpha

Question 20

(2) involved in myometrial contraction needed for the expulsion of the FETUS and PLACENTA during parturition

Answer 20

1. PGF-2 alpha
2. estrogen

Question 21

This engagement of fetus in cervical canal is what we call the _______ ___.

Answer 21

Ferguson’s reflex

Question 22

At -5 or 5 days before parturition you would see that the fetal cortisol begins to _____ as it nears parturition.

Answer 22

increase

Question 23

increase in fetal cortisol stimulates the enzymes in the dam (specifically in the adrenal gland) to _______ progesterone
level

Answer 23

decrease

Question 24

This decrease in progesterone results in an _______ in estrogen production.

Answer 24

increase

Question 25

Oxytocin secretion also starts days before parturition which acts on uterus causing production of _____ ____ near parturition

Answer 25

PGF2 alpha