Chemical Coordination and Integration Test - 5

Oxytocin is released into the blood from the posterior lobe (neurohypophysis) of the pituitary gland.

Rennin is a proteolytic hormone which is secreted by the cells of kidney. It increases the absorption of water and Na⁺ ions.

Thyroid hormone increases the number of receptors available for epinephrine at the latter's target cell, thereby increasing epinephrine's effect on that cell. Without the thyroid hormones, epinephrine would have only a weak effect. This interaction is called permissiveness.

The primary function of thymus gland is to promote the development of specific cells of the immune system called T lymphocytes (cells involved in cellular immunity), thus damage to thymus would result in loss of cell mediated immunity.

Anterior pituitary originates from Rathke's pouch, which is an embryonic invagination of the pharyngeal epithelium, and thus, it has epithelioid nature of cells.

Parathormone is completely inactive in subjects with rickets because parathormone requires vitamin D to bring about its effect on bone, and rickets is caused due to vitamin D deficiency.

Cortisol affects muscle tissue balance by increasing protein breakdown and decreasing protein synthesis, thus it is a catabolic hormone.

Irisin is secreted by muscles, and it converts white fat to brown fat. White fat has lesser mitochondria as compared to brown fat; therefore, brown fat expends more energy. By converting white fat to brown fat, it causes an increase in metabolism, thus allowing our body to burn more calories.

Glucagon secretion increases with low blood glucose to raise the concentration of glucose in the bloodstream. Exercise also stimulates secretion of glucagon.

Somatostatin secretion is induced at low pH. When pH is low, somatostatin inhibits acid secretion by direct effects on parietal cells, and also by inhibiting release of the positive regulators histamine and gastrin.