hormones (endocrine system)

Growth hormone (GH, somatotropin)

Pituitary (anterior lobe) Peptide hormone that stimulates growth, protein synthesis, and cell division; increases lipolysis.

Prolactin (PRL)

Pituitary (anterior lobe) Stimulates mammary gland development and milk production.

Adrenocorticotropic hormone (ACTH)

Pituitary (anterior lobe) Stimulates the adrenal cortex to release cortisol.

Thyroid-stimulating hormone (TSH)

Pituitary (anterior lobe) Stimulates thyroid gland to release T3 and T4, increasing metabolism.

Follicle-stimulating hormone (FSH)

Pituitary (anterior lobe) Stimulates growth of ovarian follicles in females and spermatogenesis in males.

Luteinizing hormone (LH)

Pituitary (anterior lobe) Triggers ovulation and corpus luteum formation in females; stimulates testosterone secretion in males.

Oxytocin

Pituitary (posterior lobe) Stimulates uterine contractions during labor and milk ejection from mammary glands.

Vasopressin (ADH)

Pituitary (posterior lobe) Increases water reabsorption in kidneys and constricts blood vessels to raise blood pressure.

Thyroxine (T4)

Thyroid gland Amino acid derivative that increases basal metabolic rate and oxygen consumption.

Triiodothyronine (T3)

Thyroid gland Amino acid derivative; active form that regulates energy metabolism and growth.

Calcitonin

Thyroid gland Peptide hormone that lowers blood calcium levels by inhibiting bone resorption.

Parathyroid hormone (PTH)

Parathyroid glands Protein hormone that raises blood calcium and lowers phosphate by stimulating bone resorption and renal reabsorption.

Adrenaline (epinephrine)

Adrenal medulla Amino acid derivative that increases heart rate, blood pressure, and blood glucose during stress.

Noradrenaline (norepinephrine)

Adrenal medulla Amino acid derivative that causes vasoconstriction and increases blood pressure.

Cortisol

Adrenal cortex (zona fasciculata) Steroid hormone that increases gluconeogenesis, suppresses inflammation, and helps the body cope with stress.

Aldosterone

Adrenal cortex (zona glomerulosa) Steroid hormone that promotes sodium retention and potassium excretion in kidneys.

Androgens

Adrenal cortex (zona reticularis) Steroid hormones that contribute to secondary sex characteristics.

Insulin

Pancreas (β-cells, islets of Langerhans) Protein hormone that lowers blood glucose by promoting glucose uptake and glycogen synthesis.

Glucagon

Pancreas (α-cells) Polypeptide hormone that raises blood glucose by stimulating glycogen breakdown and gluconeogenesis.

Somatostatin

Pancreas (δ-cells) Peptide hormone that inhibits insulin, glucagon, and digestive enzyme secretion.

Testosterone

Testes (Leydig cells) Steroid hormone that promotes spermatogenesis, protein synthesis, and male secondary sex traits.

Inhibin

Testes and ovaries Protein hormone that inhibits FSH secretion from the pituitary.

Estrogen (estradiol)

Ovaries (follicles) Steroid hormone that promotes development of female secondary sex characteristics and endometrial growth.

Progesterone

Ovaries (corpus luteum) Steroid hormone that maintains the uterine lining and supports pregnancy.

Relaxin

Ovaries (corpus luteum, placenta) Peptide hormone that relaxes pelvic ligaments and softens the cervix before birth.

Melatonin

Pineal gland Amino acid derivative that regulates circadian rhythms and reproductive cycles.

Thymosin

Thymus gland Peptide hormone that stimulates T-lymphocyte development and immune response.

Erythropoietin (EPO)

Kidneys Glycoprotein hormone that stimulates red blood cell production in the bone marrow.

Renin

Kidneys Enzyme that activates the renin-angiotensin-aldosterone system (RAAS) to regulate blood pressure.

Calcitriol (active vitamin D3)

Kidneys Steroid-like hormone that increases calcium absorption in the intestine.

Leptin

Adipose tissue Peptide hormone that suppresses appetite and regulates energy balance.

Ghrelin

Stomach Peptide hormone that stimulates hunger and growth hormone release.

Gastrin

Stomach mucosa Peptide hormone that stimulates gastric acid secretion.

Secretin

Duodenum Peptide hormone that stimulates pancreatic bicarbonate secretion.

Cholecystokinin (CCK)

Small intestine Peptide hormone that stimulates gallbladder contraction and pancreatic enzyme secretion.

Human chorionic gonadotropin (hCG)

Placenta Glycoprotein hormone that maintains corpus luteum and progesterone production during early pregnancy.

Human placental lactogen (hPL)

Placenta Peptide hormone that modifies maternal metabolism to supply nutrients to the fetus.

Relaxin (placental)

Placenta Peptide hormone that facilitates childbirth by relaxing uterine and pelvic tissues.

Prostaglandins

Most tissues Lipid-derived hormones that regulate inflammation, smooth muscle contraction, and blood flow.

Histamine

Mast cells and basophils Amino acid derivative that mediates allergic responses and gastric acid secretion.

Serotonin

Intestinal enterochromaffin cells, brain Amino acid derivative that regulates mood, appetite, and digestion.

--- HYPOTHALAMUS ---

Thyrotropin-releasing hormone (TRH)

Hypothalamus peptide hormone that stimulates TSH release from the anterior pituitary.

Corticotropin-releasing hormone (CRH)

Hypothalamus peptide hormone that stimulates ACTH secretion.

Gonadotropin-releasing hormone (GnRH)

Hypothalamus peptide hormone that stimulates FSH and LH secretion.

Growth hormone-releasing hormone (GHRH)

Hypothalamus peptide hormone that stimulates GH release.

Somatostatin (GHIH)

Hypothalamus peptide hormone that inhibits GH and TSH secretion.

Prolactin-inhibiting hormone (dopamine)

Hypothalamus catecholamine that inhibits prolactin secretion.

--- PITUITARY GLAND ---

Growth hormone (GH)

Anterior pituitary peptide hormone that promotes growth, protein synthesis, and lipolysis.

Prolactin (PRL)

Anterior pituitary protein hormone that stimulates milk production.

Adrenocorticotropic hormone (ACTH)

Anterior pituitary peptide hormone that stimulates cortisol release from adrenal cortex.

Thyroid-stimulating hormone (TSH)

Anterior pituitary glycoprotein hormone that stimulates T3 and T4 secretion.

Follicle-stimulating hormone (FSH)

Anterior pituitary glycoprotein hormone that stimulates gamete maturation.

Luteinizing hormone (LH)

Anterior pituitary glycoprotein hormone that triggers ovulation and testosterone synthesis.

Oxytocin

Posterior pituitary peptide hormone that stimulates uterine contractions and milk ejection.

Vasopressin (ADH)

Posterior pituitary peptide hormone that increases water reabsorption in kidneys.

--- THYROID GLAND ---

Thyroxine (T4)

Thyroid amino acid derivative that increases basal metabolic rate.

Triiodothyronine (T3)

Thyroid amino acid derivative that regulates energy use and growth.

Calcitonin

Thyroid peptide hormone that lowers blood calcium by inhibiting bone resorption.

--- PARATHYROID GLANDS ---

Parathyroid hormone (PTH)

Parathyroid protein hormone that raises blood calcium and lowers phosphate levels.

--- ADRENAL GLANDS ---

Adrenaline (epinephrine)

Adrenal medulla catecholamine that increases heart rate and blood glucose.

Noradrenaline (norepinephrine)

Adrenal medulla catecholamine that causes vasoconstriction and increases blood pressure.

Aldosterone

Adrenal cortex steroid that regulates sodium and potassium balance.

Cortisol

Adrenal cortex steroid that promotes gluconeogenesis and stress adaptation.

Androgens (DHEA)

Adrenal cortex steroids that support secondary sex traits.

--- PANCREAS ---

Insulin

Pancreatic β-cells protein hormone that lowers blood glucose and promotes glycogen and lipid synthesis.

Glucagon

Pancreatic α-cells polypeptide that raises blood glucose via glycogenolysis and gluconeogenesis.

Somatostatin

Pancreatic δ-cells peptide hormone that inhibits insulin and glucagon secretion.

Pancreatic polypeptide

Pancreatic PP-cells peptide that regulates pancreatic enzyme secretion and appetite.

--- GONADS: OVARIES ---

Estrogens (estradiol, estrone, estriol)

Ovarian steroid hormones that promote female traits and follicle development.

Progesterone

Ovarian steroid hormone that maintains uterine lining and pregnancy.

Relaxin

Ovarian and placental peptide hormone that softens cervix and pelvic ligaments.

Inhibin

Ovarian peptide hormone that inhibits FSH secretion.

--- GONADS: TESTES ---

Testosterone

Testicular Leydig cell steroid hormone that stimulates spermatogenesis and male characteristics.

Inhibin

Testicular Sertoli cell peptide hormone that inhibits FSH secretion.

--- PINEAL GLAND ---

Melatonin

Pineal amino acid derivative that regulates circadian rhythms and seasonal breeding.

--- THYMUS ---

Thymosin

Thymus peptide hormone that stimulates T-cell maturation and immune development.

--- PLACENTA ---

Human chorionic gonadotropin (hCG)

Placental glycoprotein hormone that maintains corpus luteum and progesterone production.

Human placental lactogen (hPL)

Placental peptide hormone that regulates maternal metabolism for fetal nutrition.

Relaxin (placental)

Placental peptide hormone that aids childbirth by relaxing uterine tissues.

Progesterone (placental)

Placental steroid hormone that maintains pregnancy.

--- KIDNEYS ---

Erythropoietin (EPO)

Renal glycoprotein hormone that stimulates red blood cell production.

Renin

Renal enzyme that activates the renin-angiotensin-aldosterone system (RAAS).

Calcitriol (active vitamin D3)

Renal steroid-like hormone that increases intestinal calcium absorption.

--- DIGESTIVE TRACT ---

Gastrin

Stomach peptide hormone that stimulates gastric acid secretion.

Secretin

Duodenum peptide hormone that stimulates pancreatic bicarbonate release.

Cholecystokinin (CCK)

Small intestine peptide hormone that stimulates bile and pancreatic enzyme secretion.

Ghrelin

Stomach peptide hormone that stimulates hunger and GH release.