Write short notes on the functions of the following hormones: (Any four)
$(a)$ Parathyroid hormones $(PTH)$
$(b)$ Thyroid hormones
$(c)$ Thymosin
$(d)$ Androgens
$(e)$ Estrogens
$(f)$ Insulin and Glucagon

(A) Parathyroid hormone $(PTH)$ increases the level of calcium ions in the blood by acting on bones and kidneys.
$(b)$ Thyroid hormones $(T_3$ and $T_4)$ regulate the basal metabolic rate,support the process of red blood cell formation,and control the metabolism of carbohydrates,proteins,and fats.
$(c)$ Thymosin plays a major role in the differentiation of $T$-lymphocytes,which provide cell-mediated immunity,and promotes the production of antibodies.
$(d)$ Androgens regulate the development,maturation,and functions of the male accessory sex organs and stimulate muscular growth,facial and axillary hair,and aggressiveness.
$(e)$ Estrogens produce wide-ranging actions such as stimulation of growth and activities of female secondary sex organs,development of growing ovarian follicles,and appearance of female secondary sex characters.
$(f)$ Insulin acts mainly on hepatocytes and adipocytes to enhance cellular glucose uptake and utilization,thereby lowering blood glucose levels. Glucagon acts mainly on the liver cells and stimulates glycogenolysis,resulting in an increased blood sugar level.