Q.(a) Mention the name of germ layer from which adrenal cortex and pancreas are developed.

The adrenal cortex develops from mesoderm, while the pancreas (including the islets of Langerhans) develops from endoderm. The alpha (α) cells of the islets of Langerhans secrete the hormone glucagon, which raises blo...

Adrenal cortex is mesodermal, pancreas is endodermal; islet alpha cells secrete glucagon (raises blood sugar), delta cells secrete somatostatin (regulates insulin/glucagon release).

1. Germ layer origin: The adrenal cortex (the outer part of the adrenal gland, distinct from the adrenal medulla which is derived from neural crest ectoderm) develops embryologically from mesoderm. The pancreas, including both its exocrine acinar tissue and its endocrine islets of Langerhans, develops from endoderm, arising from the embryonic gut lining.
2. Roles of alpha and delta cells of the islets of Langerhans: The islets of Langerhans, the endocrine portion of the pancreas, contain multiple cell types with distinct secretory roles. The alpha (α) cells, typically located at the periphery of the islet, secrete the hormone glucagon; glucagon acts mainly on the liver to raise blood glucose levels when they fall too low, by stimulating glycogenolysis (breakdown of stored glycogen to glucose) and gluconeogenesis (synthesis of new glucose from non-carbohydrate sources), thus acting as an antagonist to insulin. The delta (δ) cells, present in smaller numbers within the islets, secrete the hormone somatostatin, which acts locally within the islet in a paracrine manner to inhibit and regulate the secretion of both insulin (from beta cells) and …