Hormones and Their Actions (GATE - XL)

Correct answer. Gastric inhibitory peptide (GIP) inhibits gastric secretion and motility.

This option is correct because thymosin is secreted by the thymus gland. Thymosins play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity. In addition, thymosins also promote production of antibodies to provide humoral immunity.

Correct answer.
Atrial natriuretic factor (ANF) is a powerful vasodilator and a protein (polypeptide) hormone secreted by heart muscle cells.
Melanocyte-stimulating hormones (MSH) are a class of peptide hormones that are produced by cells in the intermediate lobe of the pituitary gland.
Vasopressin, also known as antidiuretic hormone, is a nine amino acid peptide secreted from the posterior pituitary.

The adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. These are commonly called catecholamines.

Correct answer.
Corticoids which regulate the balance of water and electrolytes in our body are called mineralocorticoids. Aldosterone is the main mineralocorticoid in our body. Aldosterone acts mainly at the renal tubules and stimulates the reabsorption of Na⁺ and water and excretion of K⁺ and phosphate ions. Thus, aldosterone helps in the maintenance of electrolytes, body fluid volume, osmotic pressure and blood pressure.

Glucagon acts mainly on the liver cells (hepatocytes) and stimulates glycogenolysis, resulting in an increased blood sugar (hyperglycemia).
Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue), and enhances cellular glucose uptake and utilisation, resulting in rapid movement of glucose from blood to hepatocytes and adipocytes, resulting in decreased blood glucose levels (hypoglycemia).

Correct matching is P - 3, Q - 2, R - 1, S - 4.

Luteinising hormone (LH) and follicle stimulating hormone (FSH) stimulate gonadal activity and hence, are called gonadotrophins.

This option is correct because parathormone or parathyroid hormone is produced and secreted by the parathyroid gland that regulates serum calcium concentration. Parathormone is a polypeptide containing 84 amino acids.

Epinephrine (also known as adrenaline or 4,5-β-trihydroxy-N-methylphenethylamine) is a hormone and a neurotransmitter.
Norepinephrine (also known as noradrenaline or 4,5-β-trihydroxyphenethylamine) is a catecholamine with multiple roles including those as a hormone and a neurotransmitter.

Somatostatin is secreted in several locations in the digestive system: stomach, intestine, and delta cells of the pancreas. In hypothalamus, somatostatin is produced by neuroendocrine neurons of the ventro medial nucleus.

Glucagon is a peptide hormone, produced by alpha cells of the pancreas.
Insulin is a peptide hormone synthesized, packaged and secreted in pancreatic beta cells.

Acromegaly is a syndrome that results when the anterior pituitary gland produces excess growth hormone (GH) after epiphyseal plate closure at puberty.
Cushing's syndrome is a hormonal disorder caused by high levels of cortisol which is produced in the human body by the adrenal gland in the zona fasciculate.
Syndrome off Inappropriate Antidiuretic Hormone (SIADH) occurs when excessive levels of adrenocorticotropic hormone (ADH) is secreted from the posterior pituitary.

Secretin, a hormone produced in the S cells of the duodenum, regulates water homeostasis throughout the body, and influences the environment of the duodenum by regulating secretions in the stomach and pancreas.

Melanocyte stimulating hormone (MSH) is secreted by pars intermedia region of adenohypophysis of pituitary gland.