T HYROID G LAND located at _________________________________ two important thyroid hormones (which regulate body metabolism, growth, and differentiation of tissues) __________________________________________

H ORMONES THAT AFFECT METABOLISM Three different glands affect metabolism ____________________________________________ helps regulate body metabolism (glucose oxidation rate) produces three hormones triiodothyronine, thyroxine, calcitonin ______________________________________________ produces parathyroid hormone helps regulate calcium levels in blood and lower phosphate levels _______________________________________________ produces growth hormones and regulatory hormones

H ORMONES T HAT A FFECT M ETABOLISM GlandHormoneAction Thyroid Parathyroid Anterior Pituitary Gland

T HYROID G LAND individuals who secrete higher levels of thyroxine oxidize sugars and other nutrients _____________ __________________________________________ When glycogen stores are filled, excess sugar is converted to ___________________________ control of thyroid hormones is accomplished by ____________________

F EEDBACK LOOP... receptors in hypothalamus are activated if the metabolic rate __________________________ nerve cells secrete ______ (thyroid releasing hormone) this stimulates pituitary to release _________(thyroid stimulating hormone) carried by blood to thyroid gland which then releases ___________________________which raises metabolism by _______________________________ ____________________________________by cells high levels of thyroxine cause pathway to be turned ________________, inhibiting release of TRH Thyroid gland also contains ________________________ hormone acting on _________________cells to lower level of __________________________found in blood

O H NO ! when inadequate amounts of iodine are obtained from the diet, thyroid enlarges, producing a _________. If thyroxine levels ↓’s, TSH ↑’s, and thyroid is stimulated more and more Thyroid cells continue to develop and thyroid _________________

P ARATHYROID G LANDS ____________________parathyroid glands hidden within larger thyroid gland Usually nerves or other hormones regulate the endocrine glands with the parathyroid glands being the ________________________________ These maintain homeostasis by responding __________________________________in their immediate surroundings (low calcium levels) PTH raises _______________levels in the blood PTH (parathyroid hormone) also help activate vitamin D. (Low levels of vit D cause rickets!)

R ICKETS AND G OITERS...

R EGULATION OF B LOOD C ALCIUM blood calcium level (10 mg/100mL) calcitonin parathyroid hormone (PTH)  Ca ++ uptake in intestines high low Feedback Endocrine System Control  kidney reabsorption of Ca ++ bones release Ca ++  kidney reabsorption of Ca ++ Ca ++ deposited in bones activated Vitamin D thyroid parathyroid

H UMAN G ROWTH H ORMONE ( AKA S OMATOTROPIN ) Too little = __________ Too much = __________ Released by Ant. Pit. GH increases cell __________in muscle cell and connective tissue by promoting Protein Synthesis (increasing Amino Acid uptake) Promotes fat burning Dec. Levels of GH with age

HGH AND C ONTROVERSY... Should you take it?

GH affects all body cells BUT mainly ____________cells _____________________________bones of jaw, forehead, fingers and toes increase in width, once other bones can no longer increase in length (growth plates fused)