1. COMPARATIVE ANATOMY: ANIMAL BODY SYSTEMS NERVOUS SYSTEM AISD - 2009

2. Nervous System Function: Recognizes and coordinates changes in internal and external environments. ◦ Control center of the body. Invertebrate Organs  Nerve nets, ganglia, nerve rings Vertebrate Organs ◦ Main organs  Brain  Spinal cord  Peripheral nerves Describe internal and external conditions that an organism would respond to? Which organs allow you to respond? How does the body perceive or “know” what is occurring? Think about this…

3. Nervous System: Response to the environment All animals respond to their environment through specialized cells called nerve cells (neurons). In most animals nerve cells hook together to form the nervous system. Nervous systems can range from fairly simple to extremely complex. The arrangement of nerve cells from phylum to phylum can be dramatically different.

4. Section 29-2 Ganglia Brain Nerve Cells Arthropod Mollusk Cnidarian Flatworm Figure 29–12 Invertebrate Nervous Systems Think about this… What is “Ganglia” ? How does it differ from a brain? Hint: You will need to look this up Which nervous system seems to be the simplest? Why?

5. Pons Pituitary gland Hypothalamus Cerebrum Medulla oblongata Spinal cord Cerebellum Pineal gland Thalamus Section 35-3 Figure 35-9 The Brain Brain stem The Human Brain: Control center of the Nervous System

6. Human Nerve Cell: Messenger of the nervous system Think about this… What role does the neuron (nerve cell) play in response to a stimulus?