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Endocrine System. Glands & Hormones. Hormone. A chemical messenger that is produced at one site and carried by the blood to its site of action (target cells). Mechanism of Hormone Action. Hormones produce one or more of the following cellular changes:
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Endocrine System Glands & Hormones
Hormone A chemical messenger that is produced at one site and carried by the blood to its site of action (target cells)
Mechanism of Hormone Action Hormones produce one or more of the following cellular changes: • Alter plasma membrane permeability • Stimulate protein synthesis • Activate or deactivate enzyme systems • Induce secretory activity • Stimulate mitosis
Classification of Hormones • Steroid - Lipid soluble (diffuse through plasma membrane because they are made of cholesterol) • Amino acid (most are this type) - Activate secondary messengers because the hormone must 1st bind to the plasma membrane - Secondary messengers – cAMP, DAG, IP3
Secondary messengers Hormone activates a G protein activates phosphatydal inositol biphosphate PIP2 which breaks into Diacyleglycerol DAG+ IP3 and inositol triphosphate These activate calcium release from the E.R. and protein kinases in the cell which phosphorylates proteins (adds PO4 )
Pituitary Gland 1.ACTH (Adrenocorticotropic hormone) Stimulates adrenal glands to make Cortisol and aldosterone 2. ADH (Antidiuretic hormone) Causes kidneys to reabsorb more water preventing dehydration 3. GH (Growth hormone) (Causes bone and muscle growth) 4. TSH (Thyroid stimulating hormone) (Stimulates thyroid gland to make T3 and T4)
Pituitary Gland 5. LH (Luitenizing hormone) (Stimulates estrogen & progesterone secretion from ovaries & testosterone secretion from testes) 6. FSH (Follicle stimulating hormone) (Egg & sperm production) 7. Oxytocin (Causes uterine contractions & milk ejection) 8.Prolactin (milk production) 9. MSH(Melanocyte Stimulating Hormone) Causes melanin production in skin
Pineal Gland • Melatonin (Initiates sleep)
Thyroid Gland T3 (Triiodothyronine) (Controls metabolism) T4(Thyroxin) • Glucose oxidation • Increasing metabolic rate • Heat production • Maintaining blood pressure • Regulating tissue growth • Developing skeletal and nervous systems • Maturation and reproductive capabilities Calcitonin (Builds up bone to lower blood calcium)
Parathyroid Gland PTH (Parathyroid hormone) (Breaks down bone to raise blood calcium)
Thymus Gland • Thymosin (Controls immune system)
Pancreas • Insulin (Allows glucose to enter cells; LOWERS blood glucose) • Glucagon (Stimulates liver to make glucose; RAISES blood glucose) Islets of Langerhans have two cell types • Alpha () cells that produce glucagon • Beta () cells that produce insulin
Adrenal Glands Medulla a.Epinephrine (adrenaline) (Increases: blood glucose, heart rate, blood pressure, breathing rate, & dilates bronchioles) b.Nor-epinephrine (nor-adrenaline) (Same as Epinephrine)
Adrenal Glands Cortex a.Cortisol (Stress released to increase blood glucose) b.Aldosterone (Controls salt & water balance) c.Androgens (small amounts of estrogen and testosterone)
Ovaries • 1.Estrogen (Creates female secondary sex characteristics) • 2.Progesterone(Thickens the uterus lining each month)
Testes • 1. Testosterone (Creates male secondary sex characteristics)
Kidneys Erythropoeitin – RBC production Renin and Angiotensinogen which control blood volume Renin-angiotensin mechanism – kidneys release renin, which is converted into angiotensin II that in turn stimulates aldosterone release Plasma concentration of sodium and potassium – directly influences the adrenal cells
Heart • ANP (Atrial Naturetic Polypeptide) which causes Na ions to be excreted in the kidney (Lose water & ultimately blood pressure)