The following hormone is not secreted by anterior pituitary :

Question

Accepted Answer

The correct option is 4:

Oxytocin is the correct answer because it is a hormone that is **stored and released** by the posterior pituitary gland, not secreted (produced) by the anterior pituitary gland. The pituitary gland is anatomically and functionally divided into two distinct lobes: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis). Oxytocin is actually synthesized by neurosecretory cells located in the **hypothalamus** (specifically the paraventricular and supraoptic nuclei) and then transported down the nerve axons to the posterior pituitary. From there, it is released directly into the bloodstream upon specific nerve impulse signals. This is a key distinguishing feature in neuroendocrinology, as the posterior pituitary merely acts as a storage and release site, whereas the anterior pituitary actively synthesizes and secretes its own panel of regulating hormones. Oxytocin's primary physiological roles are stimulating uterine contractions during labor and promoting milk ejection (let-down) during lactation.

The incorrect option is 1:

ACTH stands for Adrenocorticotropic Hormone, and it is a major hormone that is synthesized and secreted by the **anterior pituitary** gland. It is produced by the corticotroph cells within the anterior lobe. The function of ACTH is to stimulate the adrenal cortex, specifically the zona fasciculata and zona reticularis. This stimulation leads to the production and secretion of glucocorticoids, most importantly cortisol, which is crucial for regulating metabolism and the body's response to stress. Therefore, ACTH is fundamentally a product of the anterior pituitary, making this option incorrect.

The incorrect option is 2:

FSH, or Follicle-Stimulating Hormone, is correctly categorized as a hormone secreted by the **anterior pituitary** gland. It is one of the two main gonadotropic hormones (the other being LH) secreted by the gonadotroph cells. FSH plays a vital role in the reproductive system of both males and females. In women, it stimulates the growth and development of ovarian follicles and the maturation of the egg cell. In men, it is essential for stimulating the production of sperm within the testes. Because it is synthesized and secreted directly by the anterior lobe, it cannot be the hormone that is *not* secreted by it.

The incorrect option is 3:

Prolactin (PRL) is a peptide hormone produced and secreted by the lactotroph cells (also called mammotrophs) of the **anterior pituitary** gland. Unlike some other anterior pituitary hormones, the primary control from the hypothalamus is inhibitory, mainly via dopamine. Prolactin's central function is its effect on the mammary glands. It stimulates the growth and development of the mammary glands (mammogenesis) and, after childbirth, it initiates and maintains the production of milk (lactogenesis). Since Prolactin is a primary secretory product of the anterior pituitary, its inclusion among the options makes it an incorrect choice for the question posed.