Hormones Lecture Note

VALOIS, ANDREI FRANCE, BERNARDO BS Biology 2 (CAS 2-A) LAB REPORT 24 Hormones Hormone Gland (Source) Posterior Antidiuretic hormone Pituitary Gland Oxytocin (OT) Posterior Pituitary Target Kidneys (renal tubules) Increases water reabsorption in the kidneys, reducing urine volume and conserving body water; also causes vasoconstriction at higher concentrations. Uterus, Mammary Glands Stimulates uterine contractions during childbirth; triggers milk ejection ("milk letdown") during breastfeeding. Liver, Muscle, Bone, Cartilage, Adipose tissue Promotes growth of body tissues (especially bone and muscle); stimulates protein synthesis, fat breakdown, and glycogenolysis; has anabolic effects. Gland Anterior Growth hormone (GH) Pituitary Gland Action Thyroid-stimulating hormone (TSH) Anterior Pituitary Gland Thyroid Gland Stimulates the thyroid gland to produce and release thyroid hormones (T3 and T4). Adrenocorticotropic hormone (ACTH) Anterior Pituitary Gland Adrenal Cortex Stimulates the adrenal cortex to produce and secrete glucocorticoids (e.g., cortisol) and adrenal androgens. Melanocytestimulating hormone (MSH) Anterior Pituitary Gland Melanocytes Influences skin pigmentation by stimulating melanin production in melanocytes; also has roles in appetite and sexual arousal in some animals. Luteinizing hormone (LH) Follicle-stimulating hormone (FSH) Prolactin (PRL) Anterior Pituitary Gland Ovaries (females), Testes (males) Females: Triggers ovulation and stimulates the formation of the corpus luteum and progesterone production. Males: Stimulates Leydig cells in the testes to produce testosterone. Females: Stimulates the growth and development of ovarian follicles and estrogen production. Anterior Pituitary Gland Ovaries (females), Testes (males) Anterior Pituitary Gland Mammary Glands Promotes milk production (lactation) after childbirth; also has effects on reproductive function and immune system. Increases basal metabolic rate; regulates growth and development; influences many physiological processes including heart rate, digestion, muscle function, and brain development. Males: Stimulates spermatogenesis (sperm production) in the testes. Thyroid hormone (T3/T4) Thyroid Gland Most body cells Calcitonin (CT) Thyroid Gland Decreases blood calcium levels by inhibiting Bones (Osteoclasts), osteoclast activity (bone breakdown) and Kidneys increasing calcium excretion by the kidneys. Parathyroid hormone Parathyroid (PTH) Gland Epinephrine (Epi) Aldosterone Adrenal Medulla Adrenal Cortex Increases blood calcium levels by stimulating osteoclast activity, increasing calcium Bones (Osteoclasts), reabsorption in the kidneys, and promoting Kidneys, Intestines vitamin D activation, which enhances calcium absorption in the intestines. Most body cells (especially heart, blood vessels, bronchioles) Part of the "fight-or-flight" response; increases heart rate and contractility, vasoconstriction (in some areas) and vasodilation (in others), bronchodilation, and glycogenolysis; prepares the body for immediate action. Kidneys (renal tubules) Regulates blood pressure and electrolyte balance by promoting sodium reabsorption and potassium excretion in the kidneys; part of the Renin-Angiotensin-Aldosterone System (RAAS). Cortisol Hormone Adrenal Cortex Gland/Tissue Most body cells A glucocorticoid: involved in stress response, increases blood glucose (gluconeogenesis), suppresses the immune system, reduces inflammation, and influences metabolism of carbohydrates, proteins, and fats. Target Organ(s)/Tissue(s) Major Action(s) Melatonin Pineal gland Brain, various cells Regulates sleep-wake cycles (circadian rhythm), antioxidant. Thymosin Thymus gland T-lymphocytes (immune system) Promotes the maturation and differentiation of T-lymphocytes. Insulin Most body cells, liver, Pancreas (beta cells) muscle, adipose tissue Lowers blood glucose by promoting glucose uptake, glycogenesis, and fat synthesis. Glucagon Pancreas (alpha cells) Liver, adipose tissue Raises blood glucose by promoting glycogenolysis and gluconeogenesis. Testosterone Testes (Leydig cells), adrenal cortex Male reproductive organs, muscles, bones, hair follicles, brain Stimulates development of male secondary sexual characteristics; promotes spermatogenesis; muscle and bone growth. Estrogen Ovaries (follicle cells), adrenal cortex, placenta Stimulates development of female Female reproductive organs, secondary sexual characteristics; breasts, bones, brain, skin regulates menstrual cycle; supports pregnancy; bone health. Progesterone Ovaries (corpus luteum), adrenal cortex, placenta Uterus, breasts Prepares uterus for pregnancy; maintains pregnancy; involved in mammary gland development. Prostaglandin(s) Various tissues (local production) Various tissues (e.g., smooth muscle, blood vessels, immune cells) Diverse actions including inflammation, pain, fever, blood clotting, labor induction, gastric mucus secretion, blood pressure regulation.