1.  http://www.youtube.com/watch?v=U6uHotl XvPo http://www.youtube.com/watch?v=U6uHotl XvPo  Cells in both multicellular and unicellular organisms need to communicate in order to coordinate activities.  Ex. How does your brain communicate to your stomach that you are full Cells use various methods of communication. Ex. Nerve signals and hormone signals CELL COMMUNICATION

2.  Act slowly and in small amounts  Influenced by factors in the environment and body  Different hormones have different effects on tissues,organs, and metabolism  Hormones can only affect those cells that have receptors for those hormones  A signaling cell produces a signal, that is detected by the target cell.  Typically, target cells have specific proteins that recognize and respond to the signal. HORMONE SIGNALS

3.  TSH – Stimulates the thyroid (role in metabolism)  Growth Hormone – stimulates body cells to increase in size – major targets bones  Antidiuretic hormone – influence water balance in the body – targets kidneys  Pancreatic hormones – regulate blood sugar TYPES OF HORMONES

4.  Rapid communication throughout body  Voluntary and involuntary control  Use neurotransmitters NERVE SIGNALS

5.  Neighboring cells can communicate through direct contact between their membranes.  Long-distance signals are carried by hormones and nerve cells.

6.  A target cell is bombarded by hundreds of signals. But it recognizes and responds only to the few signals that are important for its function.  This response to some signals, but not to others, is made possible by receptor proteins, such as the ones in the cell’s membrane.

7.  When communication fails it can impact how your body functions  Ex. Certain drugs can mimic and block hormones and nerve receptors  Certain diseases are caused by an interruption of cell communication ex. Muscular sclerosis, diabetes DISRRUPTIONS OF COMMUNICATION

8. Cell communication sometimes involves multiple steps and multiple signals That can target many different organs and tissues.