Final answer:
The statement that prolactin is synthesized in the hypothalamus is false. It is actually produced by the anterior pituitary gland, but its release is regulated by hypothalamic hormones PIH and PRH.
Step-by-step explanation:
Prolactin is not synthesized in the hypothalamus; therefore, the statement is false. Prolactin (PRL) is a hormone produced by the anterior pituitary gland. The hypothalamus, however, does play a role in regulating the secretion of prolactin through the release of prolactin-inhibiting hormone (PIH), which inhibits the release of prolactin, and prolactin-releasing hormone (PRH), which stimulates its release. Vasopressin, on the other hand, is synthesized in the hypothalamus and stored in the posterior pituitary gland before being released into the bloodstream.
The regulation of prolactin involves a positive feedback loop rather than the more common negative feedback mechanism. During breastfeeding, the suckling action of a baby initiates nerve impulses that encourage the hypothalamus to stimulate the pituitary gland to release prolactin, and this in turn prompts milk production by the mammary glands.