 Chemical Regulation  Stimuli  Glands  Secrete Hormones  Response Function of the Endocrine System….

 Includes: Endocrine glands and their hormones

 Endocrine glands secrete hormones directly into the bloodstream  Hormones are chemical messengers that cause other body parts to respond

 Hormones are very specific and can only bind to the receptors of target cells or tissues

 Growth hormone (hGH)  Stimulates the growth of long bones  Also regulates other glands  Luteinizing hormone (LH)  Causes release of egg cells. Controls production of sex hormones in men and women  Follicle-stimulating hormone (FSH)  Function: stimulates production of egg and sperm cells #3 Pituitary

Growth Hormone Diseases  Hypersecretion (too much secretion) Giantism- excessive growth about normal size  Hyposecretion (to little secretion) Dwarfism– person doesn’t grow taller than 4 feet

#4 Thyroid Thyroxin - Regulates Metabolism Calcitonin - Regulates blood calcium levels

Thyroxin Diseases  Hypersecretion- nervousness, weightloss, sleeplessness  Hyposecretion: Mental retardation, weight gain

#5 Parathyroid Parathormone  Function:  Controls calcium metabolism  Necessary for normal nerve and muscle function, blood clotting, healthy bones and teeth

Parathormone Diseases  Hyposecretion: Nerve disorders, brittle bones, clotting problems

 Cortisone and Adrenaline  Function:  Cortisone: regulates nutrient metabolism  Adrenaline: increases heart rate and breathing- handles sudden stress #7 Adrenal

 Adrenaline Disease  Hyposecretion: inability to deal with stress  Cortisone Disease  Hypersecretion: Cushing’s disease (high blood glucose, excess fat)  Hyposecretion: Addison’s disease (low blood glucose, weight loss)

 Hormones: Insulin and Glucagon  Insulin: stimulates uptake of glucose by cells.  Glucagon: converts glycogen to glucose #8- Pancreas

 Insulin  Hypersecretion: Low blood sugar  Hyposecretion: diabetes (high blood sugar)  Glucagon  High blood sugar

 Estrogen  Stimulates development of female reproductive system and sex characteristics  ex: Wider hips, breasts, menstral cycle #9 Ovaries

#10 Testes  Testosterone  Stimulates development of male reproductive system and sex characteristics  ex: deep voice, beard, body hair

Feedback Mechanisms A feedback mechanism occurs when the level of one substance influences the level of another substance or activity of another organ. It can increase the production of something (positive feedback) or it can decrease or stop the production of something (negative feedback)

 Internal feedback system that regulates the endocrine system (controls the amount of hormones in the blood)  Works like a thermostat in your home. The room is maintained at a certain temp. When the temp. drops the heat kicks in. When it starts to get hot it slows production.  *** This helps to maintain homeostasis

high blood sugar pancreas secretes more insulin low blood sugar pancreas secretes less insulin