Which of the following is NOT true about the posterior pituitary gland?

• A. It stores ADH and Oxytocin
• B. It produces ADH and Oxytocin
• C. The pars nervosa is the portion of the posterior pituitary that stores hormones
• D. It is stimulated by the hypothalamus

Answer: (B)

The crucial idea is that the posterior pituitary (neurohypophysis) does not make hormones itself; it stores and releases hormones that are produced in the hypothalamus. ADH and oxytocin are synthesized by hypothalamic neurons in the supraoptic and paraventricular nuclei, packed into secretory granules, and transported down the axons to the posterior pituitary. There, they accumulate in nerve terminals within the pars nervosa, often described as Herring bodies, and are released into the bloodstream in response to neural signaling from the hypothalamus. The pars nervosa is the region that stores these hormones, and the posterior pituitary is indeed stimulated by the hypothalamus. Therefore, saying that it produces ADH and oxytocin is not true.