(a) Insulin is reponsible for lowering the blood sugar level by converting excess of glucose to gylcogen which is stored in muscles and liver. 

(b) The hormones released by the hypothalamus controls all the secretions of hormones of pituitary gland. The hypothalamus hormones regulate the secretion and production of the pituitart hormones.  Pituitary gland regulates the activities of other glands. Thus, pituitary gland and hypothalamus function as an integrated and coordinated system.

(c) At puberty there is an increase in the testosterone secretion by Leydig’s cells. The testosterone hormone plays a major role in body growthand accelerates body growth during puberty.  

(d) Adrenal medulla and the sympathetic nervous system are closely integrated systems as the emergency hormones like adrenaline and noradrenaline are secreted during danger when nerve impulse reaches adrenal medulla via sympathetic nerves.

(e) Gonadotrophic hormone secreted by pituitary gland controls the male and the female gonads. The gonadotrophins released by the pituitary regulates the reproductive system.