Which hormone is exclusively delivered by the posterior pituitary?

The correct answer is oxytocin, which is exclusively delivered by the posterior pituitary gland. The posterior pituitary, also known as the neurohypophysis, is responsible for storing and releasing hormones that are produced in the hypothalamus. Oxytocin plays crucial roles in various physiological functions, including regulating childbirth and lactation, as well as influencing social bonding and emotional responses.

This hormone is synthesized in the hypothalamus and transported down to the posterior pituitary, where it is then released into the bloodstream in response to specific stimuli. Understanding the distinction between hormones released by the posterior pituitary and those produced and released by other glands, such as the anterior pituitary, is essential for grasping how the endocrine system functions.

The other hormones listed are produced and released by the anterior pituitary gland, not the posterior pituitary. Growth hormone and prolactin are key players in growth regulation and lactation, respectively, while follicle stimulating hormone is involved in reproductive processes. Thus, their secretion and functions differ significantly from that of oxytocin in the context of the pituitary gland's roles.