He hormone oxytocin suppresses energy metabolism during pregnancy. reduces the ability of blood to clot during the birth process. increases a woman's appetite during pregnancy. enables the "let-down" reflex to occur when a woman breastfeeds her baby.

"Let-down reflex" occurs in breastfeeding mothers, where oxytocin acts at the mammary glands, causing milk to be “let down” into sinuses (structures from where it can be released via the nipple). Suckling by the baby is the stimulus that causes neurons that make the secretion of pulses of oxytocin from the neurosecretory nerve terminals of the pituitary gland.

because of

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.