1. Aim: How do cells of the body communicate? HW 1 Read pages 1000-1015 Fill in the handout

2. Receptor molecules (proteins) play an important role in the communication between cells. Two primary agents of cellular communication are hormones, (produced by endocrine glands) and neurotransmitters, (chemicals produced by nerve cells). If nerve or hormone signals are blocked, cellular communication is disrupted and the organism’s homeostasis is affected.

3. Cell Communication

4. Endocrine Glands produce Hormones (chemicals) 1 2 3 4 5 6 7 8 9 10

5. Fast and Slow Messages Your endocrine (hormonal) system is the slow message system of your body. Its messages consist of chemicals released by glands into the bloodstream. Your nervous system, on the other hand, is the fast message system of the body. Its messages consist of electrical signals that travel along the membranes of nerve cells.

6. Steroid Hormone Target cell membrane mRNA Cytoplasm Protein synthesis Altered cellular function Receptor Hormone- receptor complex Nucleus DNA Nonsteroid hormone (first messenger) Receptor Target cell membrane cAMP (second messenger) Enzyme activities Altered cellular function Cytoplasm Nucleus Steroid and non-steroid Hormone Action Section 39-1

7. regulates Regulation by the.. Section 39-2 by means of the Growth Water balance ReproductionMetabolism Calcium and glucose levels Response to stress The Endocrine System Pituitary Ovaries TestesThyroidPancreasAdrenals Para thyroids

8. Beta cells release insulin into the blood Body cells absorb glucose Blood glucose level decreases Homeostasis: Normal blood glucose level Blood glucose level decreases Alpha cells release glucagon into blood Liver converts glycogen to glucose Blood glucose level increases Liver converts glycogen to glucose Regulation of Sugar by the feedback actions of Insulin and Glucagon Section 39-2

9. The female reproductive system is regulated by hormones Section 39-3