Physiology of Pregnancy Flashcards
What affect does Uterine contractions have on arterial flow and venous flow?
It attenuates arterial inflow and completely interrupts venous drainage
What is the first hormone produced via the synctiotrophoblasts?
hCG
Laboratory assays and OTC pregnancy tests are testing for what subunit of hCG?
B-subunit (hormone specific)
What are the endocrine functions of Human Placental Lactogen (hPL)?
Protein Anabolic, Lipolytic, & Insulin Antagonist
Which hormone contributes to the diabetogenicity of Pregnancy?
Human Placental Lactogen
What is basic mechanism for Progesterone production?
It is unregulated; Progesterone is made as much as supplies of cholesterol and enzymes Cholesterole Desmolase & 3B-HSD will allow
What is main hormone of pregnancy?
It is etriol
What hormone is secreted from the midluteal phase?
Progesterone
What are two effects in regards to both pregnancy and menstruation in terms of Progesterone?
1) Pregnancy: Stimulates maternal-to-fetal transfer nutrients
2) Menstruation: Inhibits myometrial contraction and prevents the release of paracrine factors that lead to menstruation
The “Window of Receptivity” as induced by Progesterone expression occurs from days ____ to ____ ?
20-24 days
What anatomical structures account for the increased vascularization of the uterine endothelium during implantation?
2) What is the purpose of the increased vascularization to the uterine endothelium?
1) Spiral Arteries
2) Increased vascularization to the uterine endothelium allows for increased hCG delivery to “rescue” the Corpus Luteum
What is the role in Progesterone maintaining pregnancy?
It reduces uterine contractility and inhibits propagation of contractions
After eight weeks of gestation, what becomes the primary source of estrogens and progesterones?
The placenta
What two hormones promote the inactivity of the uterus during pregnancy?
Progesterone and Relaxin
What are some common physiological changes with the stages of labor?
There are an increase in the number of GAP junctions between myometrial cells & an increase in the number of oxytocin receptors
What is the narrowest part of the pelvis?
Ischial Spine
What is defined as 0 station?
It is when the baby’s head is even with the ischial spines (mother)
What are two of Estrogens effects in the role of Parturition?
1) Increases the degree of uterine contractility
2) Stimulates the synthesis of receptors for Oxytocin in myometrial & decidual tissue
The synthesis of Prostaglandins is stimulated via what?
1) Estrogen from Arachidonic Acid in Fetal Membranes
2) Oxytocin in uterine cells
Which specific prostaglandins increase uterine motility?
PGF 2a & PGE2
When is the uterus sensitive to both oxytocin & prostaglandins?
1) Oxytocin: Uterus remains insensitive to Oxytocin until about 20 weeks of gestation
2) Prostaglandins: Uterus remains susceptible to prostaglandins throughout Pregnancy
What is the Ferguson Reflex?
It is where the release of Oxytocin is stimluated via stretch of the Cervix
What hormonal factors are primary responsible for the initiation of labor and the sustaining of labor?
1) Prostaglandins: Stimluate the onset of labor
2) Oxytocin: Stimulates powerful uterine contractions that sustain labor
How does Oxytocin stimulate Prostaglandin production?
It binds to receptors on decidual cells, thereby stimulating PGF2a production
