question_answer 19)

  A hormone responsible for normal sleep-wake cycle is (a) epinephrine                (b) gastrin                           (c) melatonin                     (d) insulin

Answer:

                  (c) Melatonin hormone plays a very important role in maintaining the normal rhythms of sleep-wake cycle. Gastrin is secreted by the endocrine cells present in the gastrointestinal tract and stimulates the secretion of hydrochloric acid and pepsinogen. Epinephrine is secreted from the adrenal gland and acts as a stress relieving hormone at the time of stress condition in the body. Insulin secreted from pancreas is involved in maintaining glucose homeostasis.