Q.List the hormones secreted by the following:

(a) Testosterone, (b) Insulin, (c) Prolactin, (d) Parathyroid hormone respectively regulate these four functions.

(a) Secondary sexual characters in males (facial/body hair, deepening of voice, muscular development, etc.) are regulated by testosterone, the principal androgen secreted by the Leydig (interstitial) cells of the testis.

(b) Lowering of blood sugar level is brought about by insulin, secreted by the beta cells of the islets of Langerhans in the pancreas. Insulin promotes glucose uptake by cells and its conversion to glycogen, thereby reducing blood glucose (it is hypoglycaemic, opposing glucagon).

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The hyperglycemic counterpart of insulin is glucagon; the deficiency counterpart of gigantism is dwarfism.

(a) Insulin is the hypoglycemic hormone (it lowers blood glucose). Its counterpart that raises blood glucose - the hyperglycemic hormone - is Glucagon (secreted by the alpha cells of the pancreas).

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Dwarfism = low Growth Hormone; Diabetes mellitus = low insulin; Cretinism = low thyroxine; Diuresis (excess urine) = low ADH.

Matching each disorder with the deficient hormone:

1. Dwarfism - caused by deficiency of Growth Hormone (GH, somatotropin) from the pituitary during childhood, giving stunted growth.
2. Diabetes mellitus - caused by deficiency (or ineffectiveness) of Insulin from the pancreas, leading to raised blood glucose and glucose in urine.
3. Cretinism - caused by deficiency of Thyroxine (thyroid hormone) in infancy, causing stunted growth and impaired mental development. …