NS 431 EXAM 3 QUESTIONS AND ANSWERS | UPDATED 2026

NS 431 EXAM 3 QUESTIONS AND ANSWERS | UPDATED 2026 Mammary gland anatomy - answer--functional unit: alveoli -secretory cells: secrete milk -myoepithelial cells: stimulate release of milk via oxytocin Lactation Hormones - answer--estrogen: ductal growth, occurs during menstruation -prolactin: alveolar development and milk secretion, 3rd trimester -HGH: development of terminal buds, mammary gland development -oxytocin: letdown, from onset of milk secretion to weaning Stages of Lactogenesis - answer-1) First few days PP, Milk formation begins, lactose/protein content increases 2) 2-5 days PP, onset of copious milk secretion, delay of stage can cause breastfeeding failure 3) 10 days PP, milk composition is stable Transportation of milk nutrients - answer--exocytosis of lactose -lipid vesicles; short/med from alveoli while long is from maternal blood -active transport of ions (Na, K, H2O) -transcytosis of proteins (immunoglobulins) -paracellular transport of leukocytes Letdown reflex feedback loop - answer-1) suckling stimulates mechanoreceptors in nipple sends signal to hypothalamus 2) Hypothalamus stimulates pituitary -posterior: oxytocin stimulates milk ejection from myoepithelial cells -anterior: prolactin stimulates milk production from secretory cellsNutrients synthesized de nova in the mammary glands - answer--lactose, requires a-lactalbumin as cofactor -casein -short(6) and medium (8-10) FA's Nutrients transferred from maternal plasma - answer--long chain FA's (12); need adequate consumption of Omega-3 and Omega-6 -majority of vitamins and minerals Milk synthesis and secretion is most active during which period? - answer--most active during feeding, less active between feedings Function of Prolactin during lactation - answer--mammary glands: milk production -reproductive organs: inhibit ovulation