Main Function: hormones into the blood It releases hormones into the blood to signal other cells to behave in certain ways. It is a slow but WIDESPREAD form of communication.
1.Endocrine glands: Release hormones DIRECTLY into the circulatory system 2.Hormones Consists of:
Chemicals released in one part of the body that travel through the bloodstream and affect the activities of cells in other parts of the body. growth hormones
Hormone fits receptor on “target” cell target cell non- target cells secreting cell can’t read signal
Pituitary Gland- “the Master Gland” Hormone: Growth Hormone 1. Stimulates bones to elongate 2. Affects metabolism
Pituitary Gland- Growth Hormone Disorders: Oversecretion: In early childhood = Gigantism In adults = Acromegaly (bones of hands, feet and face enlarge) Undersecretion: In childhood = Dwarfism Robert Wadlow
Thyroid Gland Hormone: Thyroxine Regulates metabolism (necessary for normal physical and mental development)
Thyroxine Disorders: Oversecretion: Nervousness, weightloss Undersecretion: In childhood, cretinism (mental retardation, small size)
Goiter Iodine Deficiency in the diet = an enlarged thyroid gland
Parathyroid Gland Hormone: Parathormone Controls metabolism of calcium Necessary for: Nerve and Muscle function Blood clotting Health of Bones and Teeth Parathyroid Glands
Parathormone Disorders: Undersecretion: Nerve disorders Brittle bones Clotting disorders
Adrenal Gland Hormones: Cortisone Regulates carbohydrates, protein and lipid metabolism. (Promotes the change of lipid and protein to glucose) Adrenaline 1. Raises blood sugar level 2. Increases Heartbeat & Breathing rate
Cortisone Disorders: Oversecretion: Cushing’s Disease – high blood glucose, excess of fat Undersecretion: Addison’s Disease – low blood glucose, weight loss
Adrenaline Disorders: Undersecretion: Inability to deal with stress.
Pancreas: Islets of Langerhans Hormones: Insulin Stimulates glucose uptake by cells Glucagon Promotes liver to change glycogen to glucose
Insulin Disorders: Oversecretion: Low Blood Sugar Undersecretion: High Blood Sugar = Diabetes
liver pancreas liver blood sugar level (90mg/100ml) insulin body cells take up glucose from blood liver stores sugar as glycogen reduces appetite glucagon pancreas liver releases glucose triggers hunger high low Regulation of Blood Sugar: Negative Feedback After a mealBetween meals
Negative Feedback: Nervous System high low sweating lowers temperature shivering Body Temperature raises temperature
What about the Ovaries and the Testes? Don’t worry, we’re saving them for our unit on Reproduction