When NaCl is injected in the internal carotid artery, it causes release of ADH by acting on?: (A) Paramedian nucleus, (B) Anterior pituitary, (C) Paraoptic nucleus, (D) Supraoptic nucleus
Answer is D. Osmoreceptors located in the anterior hypothalamus (preoptic nucleus), which are stimulated by NaCl injection (increase osmo­lality). Osmoreceptors have stimulatory action on thirst centre and ADH secreting supraoptic nucleus.