The Endocrine System

1. The Endocrine System

2. Def: System of glandsinvarious parts of the body that manufacture & secrete hormonesinto the bloodstream • hormones = chemical substances; Greek for “to excite”;affect other body cells • pituitary gland = just below hypothalamus; master gland that controls/turns on other glands in the endocrine system & releases a growth hormone • underactive pituitary =dwarf • overactive pituitary =giant

3. Thyroid gland = in front, lower part of neck; produces thyroxin, which regulates metabolism • metabolize = to change food into energy • hyperthyroidism (too much thyroxin) = thin, nervous, unable to relax • hypothyroidism(too littlethyroxin) = overweight, sluggish • Parathyroid gland = behind thyroid; regulates calcium metabolism • Thymus = controls lymph system; affects immune system

4. adrenal glands = just above kidneys; release epinephrine&norepinephrine which activate the sympathetic nervous system (prepares body for emergencies & stressful situations) • Adrenal glands also release: • small amounts of sex hormone • corticoids, which control the salt balance in your body • Pancreas = curved around small intestine & stomach; produces insulin & regulates blood sugar • diabetes (not enough insulin) = too much sugar in blood • hypoglycemia (too much insulin)= low blood sugar • control both with diet; diabetics sometimes inject insulin

5. Gonads = sex glands that produce sex hormones, make reproduction possible, & responsible for secondary sex characteristics • pubic & underarm hair, breasts in women, facial hair & deepened voice in men • Female gonads = ovaries (produce estrogen & progesterone) • Male gonads = testes (produce testosterone)

6. Hormonal/Endocrine System-Brief Overview for Primary/Secondary Students: youtube Gigantism – youtube