Physiology of Pregnancy Flashcards
Pregnant BP
Lower than normal
When does the placenta form?
~21 days, embryonic circulation begins then
Functions of the placenta
Provide maternal nutrients and O2 to fetus. Clear fetal waste. Confer passive immunity by transfer of antibodies. Produce hCG, hPL, estrogen, and progesterone.
hPL
Human placental lactogen, causes breast growth and lactation. Responsible for increased insulin resistance (frees up glucose for baby). Also lipolytic to mobilize free fatty acids for maternal energy.
Progesterone
Causes smooth muscle dilation. Uterus, bronchioles, gi tract, urinary tract, arterioles. Causes constipation and heartburn but increased absorption. By dilating arterioles, cardiac output is increased.
hCG
Human chorionic gonadotropin, maintains the corpus luteum and causes maternal nausea.
Pregnancy induced circulatory changes
Increased venous return, increased CO, increased blood volume. Decreased blood pressure due to placental perfusion.
Pregnancy induced respiratory changes
Increased oxygen consumption
Oxytocin
Causes muscle contractions in labor. Also causes contraction of breast myoepithelial cells which enables the let down reflex.
Why do pregnant women urinate more often?
Dilated ureter, increased blood volume causes increased renal flow. Mother has to clear by products from herself and fetus.
Three stages of labor
1) Labor contractions to full cervical dilation. 2) Dilation to delivery. 3) Delivery of baby to passage of placenta.
Effacement
Walls of cervix are pulled up causing dilation. Turtle Neck.
Effect of Estrogen/Progesterone on muscle contractility during labor.
Estrogen increases, progesterone decreases.
Colostrum
Breast milk. Full of fat and antibodies.
Lactation caused by?
Prolactin, let down is oxytocin.
