AIPMT Biology Aspirants, read out the next AIPMT Biology Study material/ Notes on Endocrine hormones, important for AIPMT Biology. Free online notes for AIPMT
Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts. Hormones help to control growth and development, maintain metabolism and energy balance etc. Below is the list of hormones, their principal actions in the body, and their respective secretory glands/ tissue.
| Gland / Tissue | Hormone | Chemical Nature | Principal Actions |
| Hypothalamus | Growth hormone–releasing hormone (GHRH); or Somatocrinin | Peptide | Causes release of growth hormone |
| Growth hormone inhibitory hormone (GHIH);or Somatostatin | Peptide | Inhibits release of growth hormone | |
| Gonadotropin-releasing hormone (GnRH) | Causes release of LH and FSH | ||
| Thyrotropin-releasing hormone (TRH) | Peptide | Stimulates secretion of TSH and prolactin | |
| Corticotropin-releasing hormone (CRH) | Peptide | Causes release of ACTH | |
| Prolactin-inhibiting factor (PIF) or Dopamine | Amine | Inhibits release of prolactin | |
| Anterior Pituitary | Human growth hormone (hGH); or Somatotropin | Peptide | Stimulates protein synthesis and overall growth of cells and tissues |
| Follicle-stimulating hormone (FSH) | Peptide | Causes growth of follicles in the ovaries and sperm maturation in Sertoli cells of testes | |
| Luteinizing hormone (LH) | Peptide | Stimulates testosterone synthesis in Leydig cells of testes; induces ovulation, formation of corpus luteum, and estrogen and progesterone synthesis in ovaries | |
| Thyroid-stimulating hormone (TSH); or thyrotropin | Peptide | Stimulates synthesis and secretion of thyroid hormones (thyroxine and triiodothyronine) | |
| Adrenocorticotropic hormone (ACTH); or corticotropin | Peptide | Synthesis and secretion of steroid hormones from the adrenal cortex (cortisol, androgens, and aldosterone) | |
| Prolactin (PRL) | Peptide | Promotes development of the female breasts and secretion of milk | |
| Melanocyte-stimulating hormone (MSH) | Acts on the melanocytes (melanin containing cells) and regulates pigmentation of the skin | ||
| Posterior Pituitary | Anti-diuretic hormone (ADH) ; or vasopressin | Peptide | Increases water reabsorption by the kidneys and causes vasoconstriction and increases blood pressure |
| Oxytocin | Peptide | Stimulates milk ejection from breasts and uterine contractions at the time of child birth | |
| Pineal Gland | Melatonin | Amine | Help in the regulation of a 24-hour (diurnal) rhythm of our body; sleep-wake cycle, body temperature, metabolism, defense |
| Thyroid | Tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3) | Amine | Increases the rates of chemical reactions in most cells, thus increasing body metabolic rate |
| Calcitonin or thyrocalcitonin(TCT) | Peptide | Promotes deposition of calcium in the bones and decreases extracellular fluid calcium ion concentration |
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| Parathyroid | Parathyroid hormone (PTH); hypercalcemic hormone | Peptide | Controls blood calcium ion concentration by increasing calcium absorption by the gut and kidneys and releasing calcium from bones; increases blood Ca2+ levels |
| Thymus | Thymosins | Peptide | Help in differentiation of T-lymphocytes; promote production of antibodies to provide humoral immunity |
| Adrenal Cortex | Cortisol (Glucocorticoid) | Steroid | Has multiple metabolic functions for controlling metabolism of proteins, carbohydrates, and fats; also has anti-inflammatory effects; stimulate gluconeogenesis and lipolysis |
| Aldosterone (Mineralocorticoid) | Steroid | Increases renal sodium reabsorption, potassium secretion, and hydrogen ion secretion |
|
| Androgens (dehydroepiandrosterone, or DHEA) | Steroid | Play a role in the growth of axial hair, pubic hair and facial hair during puberty | |
| Adrenal Medulla | Noradrenaline or norepinephrine, adrenaline or epinephrine; commonly called as catecholamines; emergency hormones or hormones of Fight or Flight | Amine | Enhance effects of sympathetic division of autonomic nervous system during stress |
| Pancreas | Insulin (β cells) | Peptide | Lowers blood glucose level by accelerating transport of glucose into cells, converting glucose into glycogen (glycogenesis), and decreasing glycogenolysis and gluconeogenesis; increases lipogenesis and stimulates protein synthesis |
| Glucagon (α cells); hyperglycemic hormone | Peptide | Raises blood glucose level by accelerating breakdown of glycogen into glucose in liver (glycogenolysis), converting other nutrients into glucose in liver (gluconeogenesis), and releasing glucose into blood |
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| Somatostatin (δ cells) | Inhibits secretion of insulin and glucagon; slows absorption of nutrients from gastrointestinal tract | ||
| Testes | Testosterone (Androgen) | Steroid | Development of male reproductive system and male secondary sexual characteristics |
| Inhibin | Inhibits secretion of FSH from anterior pituitary | ||
| Ovaries | Estrogens | Steroid | Promotes growth and development of female reproductive system, female breasts, and female secondary sexual characteristics |
| Progesterone | Steroid | Supports pregnancy, prepare mammary glands for lactation |
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| Inhibin | Inhibits secretion of FSH from anterior pituitary. | ||
| Relaxin (RLX) | Increases flexibility of pubic symphysis during pregnancy; helps dilate uterine cervix during labor and delivery | ||
| Heart (not a endocrine gland) | Atrial natriuretic factor (ANF) | Peptide | Decreases blood pressure |
| Kidney (not a endocrine gland) | Erythropoietin | Peptide | Stimulates erythropoiesis (formation of RBC) |
| Endocrine cells of Gastro-intestinal tract | Gastrin | Peptide | Stimulates the secretion of hydrochloric acid and pepsinogen |
| Gastric Inhibitory Peptide (GIP) | Peptide | Inhibits gastric secretion and motility | |
| Secretin | Peptide | Stimulates pancreatic acinar cells to release bicarbonate and water | |
| Cholecystokinin (CCK). | Peptide | Stimulates secretion of pancreatic juice; regulates release of bile from gallbladder; causes feeling of fullness after eating |
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