Final answer:
When the infant begins to suck on the nipple, sucking acts as a stimulant triggering the hypothalamus to begin the production of prolactin. This causes the pituitary gland to release prolactin to initiate milk production, and oxytocin to trigger the expulsion of milk. Since oxytocin is also released during arousal, it is not uncommon to experience feelings that remind of sexual pleasure when nursing.
Step-by-step explanation:
Sucking on the nipple initiates a hormonal response where the hypothalamus starts prolactin production, leading to milk production and release by the pituitary's prolactin and oxytocin, which can also induce feelings associated with arousal.
When an infant begins to suck on the nipple, the hypothalamus is triggered to produce prolactin and oxytocin, which initiates milk production and the expulsion of milk. This can lead to feelings of arousal and sexual pleasure during nursing.