Physiology Week 3 Flashcards
When does embryonic circulation begin?1
When placenta forms at about 21 days
What is the effect of progesterone on smooth muscle?
relaxes uterus, bronchioles, GI tract, urinary tract, and arterioles
What does the placenta produce?
hCG, hPL (human placental lactogen), estrogens and progesterone
What does hPL do?
human placental lactogen: breast growth & lactation, diabetogenic (increased insulin resistance) which frees up glucose for fetus which uses it solely for energy. Also lipolytic - mobilizes free fatty acids into maternal plasma for maternal energy.
What does HCG do?
human chorionic gonadotropin maintains the corpus luteum and causes maternal nausea
What physiologic changes occur in the circulatory system during pregnancy?
total blood volume increases (by 40%!), cardiac output increases, venous return increases, blood pressure decreases (due to onset of placental perfusion). Heart hypertrophies
What physiologic changes occur in the resp. system during preg?
increased oxygen consumption
What physiologic changes occur in the urinary system during pregnancy?
increased renal blood flow, increased urine formation
What physiologic changes occur in the digestive system during pregnancy?
increased nutrient transit time (allows for better absorption but also constipation
What happens to the pituitary gland in pregnancy
it enlarges and produces more oxytocin (post. pituitary), prolactin, corticotropin, thyrotropin, growth hormone. It produces LESS FSH and LH. (all anterior pituitary).
What does oxytocin do?
- involved in uterine contractions and postpartum uterine involution.
- (milk let down) Causes contraction of breast myoepithelial cells leading to ejection of milk from terminal duct lobular units (TDLU) into large ducts in the “let down” response to infant suckling.
