Final answer:
Prolactin-releasing hormone (PRH) stimulates prolactin secretion for milk production, while prolactin-inhibiting hormone (PIH), identified as dopamine, inhibits it. They are produced in the hypothalamus and target the anterior pituitary gland. Together, these hormones regulate the levels of prolactin and thereby control milk production in females.
Step-by-step explanation:
The student has asked about prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH), which are key components in the regulation of prolactin (PRL) levels in the body, essential for milk production in females. PRH and PIH are both produced by the hypothalamus.
A. PRH is the hormone that stimulates the release of prolactin from the anterior pituitary gland, whereas PIH, which is identified as dopamine, inhibits it.
B. Their target cells are located in the anterior pituitary gland where prolactin is produced.
C. The effect of PRH on target cells is to increase the secretion of prolactin, while PIH works to decrease it. Therefore, PRH and PIH tightly regulate the prolactin level according to the physiological needs, such as during or after pregnancy.
D. Ultimately, PRH contributes to an increase in milk production by stimulating prolactin release, while PIH inhibits milk production by reducing prolactin secretion. During pregnancy, prolactin levels rise in response to PRH and are important for the mobilization of micronutrients for breast milk.
When a releasing hormone is secreted from the hypothalamus, it travels to the anterior pituitary gland which is the part that receives it and responds by releasing various hormones such as FSH, LH, and PRL.