Microsoft PowerPoint - BIOMED DAY 2

1 2 3 4 (c) HB Kim, www.acupuncturemedia.com Page 1

GLANDS & HORMONES HYPOTHALAMUS Hypothalamus Anterior pituitary Target organ TRH (Thyrotropin releasing hormone) TSH Thyroid CRH (Corticotropin releasing hormone) ACTH Adrenal gland GnRH (Gonadotropin releasing hormone) FSH & LH Ovary, testis PRH (Prolactin releasing hormone) PRL PIH (Prolactin inhibiting hormone) PRL Mammary gland GHRH (Growth hormone releasing hormone) GH Somatostatin GH Bone, muscle, adipose tissue HOW HYPOTHALAMUS AFFECTS PITUITARY GLANDS Hypothalamus Anterior pituitary gland Hypothalamus Posterior pituitary gland Hypothalamo hypophyseal portal vein Nerve impulses Releasing/inhibiting hormone (TRH, GnRH, CRH) PITUITARY GLAND HORMONE TARGET EFFECTS FSH Ovaries, testis Ovarian follicles, estrogen Sperm production LH Ovaries, testis Ovulation Testosterone secretion ANTERIOR TSH Thyroid gland Growth of thyroid, secretion of thyroid hormone ACTH Adrenal cortex Growth of adrenal cortex, secretion of corticosteroids PRL Mammary glands, testes Milk synthesis; LH sensitivity & testosterone secretion GH Liver, bone, muscle, fat Somatomedin secretion, widespread tissue growth POSTERIOR OT Uterus, mammary glands Uterus contraction, milk release ADH Kidneys Water retention; Vasopressin (at high concentration) NEGATIVE FEEDBACK INHIBITION IN THE PITUITARY THYROID AXIS 1 The hypothalamus secretes TRH (thyrotropin releasing hormone). 2 TRH stimulates the anterior pituitary to secrete TSH (thyroid stimulating hormone). 3 TSH stimulates the thyroid gland to secrete the two thyroid hormones, T 3 and T 4. 4 T 3 and T 4 stimulate the metabolism of most cells through the body. 5 T 3 and T 4 also inhibit the release of TSH by the pituitary. 6 To a lesser extent, T 3 and T 4 also inhibit the release of TRH by the hypothalamus. Inhibition ENDOCRINE SYSTEM HB Kim (c) HB Kim, www.acupuncturemedia.com Page 4

PINEAL GLAND & THYMUS (Large in infants and children but involute after puberty) HORMONE TARGET EFFECTS PINEAL GLAND Melatonin & Serotonin Brain Influence mood May regulate the timing of puberty THYMUS Thymopoietin & Thymosins T lymphocytes Stimulate T lymphocytes THYROID & PARATHYROIDS HORMONE TARGET EFFECTS T 3 and T 4 Most tissues metabolic rate, heat production, circulation, development THYROID Calcitonin Bone blood Ca 2+ level; Ca 2+ deposition and ossification PARATHYROID PTH Bone, kidneys blood Ca 2+ level; urinary Ca 2+ excretion MEDULLA ADRENAL GLAND HORMONE TARGET EFFECTS Epinephrine, norepinephrine, dopamine Most tissues Complement effects of sympathetic nervous system, "fight or flight" Mineralocorticoids Aldosterone (zona glomerulosa) Kidney Control electrolyte balance (promotes Na + retention and excretion), maintains blood pressure and volume K + CORTEX Glucocorticoids Cortisol & Corticosterone (zona fasciculata) Most tissues Fat/protein catabolism, gluconeogenesis, stress resistance, tissue repair; inhibit immune system Sex steroids Androgen & Estrogen (zona reticularis) Bone, muscle, skin, many others Growth of pubic and axillary hair, bone growth, sex drive, male prenatal development PANCREATIC ISLETS HORMONE TARGET EFFECTS Insulin Most tissues blood glucose level; glycogen, fat, and protein synthesis Glucagon Primary liver blood glucose level; glycogen and fat breakdown GONADS HORMONE TARGET EFFECTS OVARIES Estrogen Many tissues reproductive Progesterone Uterus, mammary gland development TESTES Testosterone Many tissues reproductive development Regulates menstrual cycle and pregnancy, prepares for lactation Skeletomuscular growth, sperm production, and libido ENDOCRINE SYSTEM HB Kim (c) HB Kim, www.acupuncturemedia.com Page 5