1. ENDOCRINE SYSTEM pp 1031-1042 Warm-up 4/15: a.Describe the function of the Endocrine System. b.What tissues/ organs are part of the endocrine system?

2. FUNCTION Controls body function with chemical messengers Hormones: chemical messengers Glands: secrete chemicals/hormones

3. HORMONES Amino acid-based hormones: first messenger binds to cell surface receptor causing second messenger inside the cell to initiate cell activity

4. Steroid hormones: diffuse through cell membrane to bind to a protein which starts transcription

6. GLANDS exocrine: secrete nonhormonal chemicals through ducts (sweat, saliva, mucous, digestive, etc) endocrine: secrete hormones into the bloodstream a. gonads: sex hormones b. thyroid: metabolism c. adrenal gland: adrenaline d. pituitary: hormones that affect other glands and growth hormones e. pancreas: insulin and glucagons to regulate sugar f. thymus: stimulates formation of T-cells

7. FEEDBACK MECHANISMS Homeostasis: stable internal environment Last step of the series controls the first

8. NEGATIVE FEEDBACK A secondary substance inhibits production of the initial stimulating substance A = Insulin B = glucagon (sugar)

10. Negative feedback loops are necessary for homeostasis. Negative Feedback Loop Holding breath, CO 2 levels rise, Control system forces exhale, inhale O 2 / CO 2 level returns to normal

11. POSITIVE FEEDBACK A secondary substance stimulates production of the initial stimulating substance

12. Birth

13. HW Worksheet: Nervous and Sense Organs (Due Tuesday) Trifold Vocab: homeostasis, neuron, gland, hormone, positive feedback loop, negative feedback loop, synapse, neurotransmitter (Due Wednesday)