Final answer:
c) Prolactin and oxytocin
The hormones involved in lactation are prolactin and oxytocin, with prolactin stimulating milk production and oxytocin handling milk ejection. Additional hormones such as growth hormone, cortisol, and insulin also contribute to lactation by transporting nutrients to the breast milk. The regulation of prolactin involves a positive feedback mechanism during breastfeeding.
Step-by-step explanation:
The hormones involved in lactation are prolactin and oxytocin. Prolactin, which is released from the anterior pituitary gland, is primarily responsible for promoting lactation by stimulating the milk production in the mammary glands. Oxytocin, produced in the hypothalamus and released by the posterior pituitary gland, causes the milk let-down reflex, enabling the milk to be ejected from the alveoli of the mammary glands to the nipples.
Other hormones such as growth hormone, cortisol, parathyroid hormone, and insulin also support lactation by facilitating the transport of nutrients like amino acids, fatty acids, glucose, and calcium to the breast milk. For example, during the final weeks of pregnancy, the alveoli in the breasts fill with colostrum, a nutrient-rich precursor to mature breast milk, which begins to be secreted in larger volumes after childbirth.
The regulation of prolactin is influenced by a positive feedback mechanism during breastfeeding: the act of suckling triggers nerve impulses that prompt the hypothalamus to stimulate more prolactin release, and thus, more milk production. This positive feedback loop continues until the baby stops suckling.