1. © 2006 McGraw-Hill Higher Education. All rights reserved. Chapter 4 The Nervous System

2. © 2006 McGraw-Hill Higher Education. All rights reserved. Homeostasis

3. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.1 Every neuron has four regions: cell body, dendrites, axon, presynaptic terminals.

4. © 2006 McGraw-Hill Higher Education. All rights reserved. Neurotransmission  All nervous systems consist of specialized nerve cells called neurons  Neurons are responsible for receiving and sending information  Sending and receiving information is a highly specialized, precise and very rapid

5. © 2006 McGraw-Hill Higher Education. All rights reserved. Neurotransmission  The receiving region of the neuron is affected by a chemical message that either excites or inhibits  If the message is excitatory, an impulse moves from the receiving region of the neuron down the axon to the sending region, the terminal, and chemical messengers, neurotransmitters, are released

6. © 2006 McGraw-Hill Higher Education. All rights reserved. The Nervous Systems  Somatic Nervous System  Sensory information  Voluntary actions  The Autonomic Nervous System (ANS)  Sympathetic  Parasympathetic  The Central Nervous System  The Brain  Chemical Pathways

7. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.3

8. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.4

9. © 2006 McGraw-Hill Higher Education. All rights reserved. Common Neurotransmitters Neurotransmittertype of effectCNS changesdrugs of abuse dopamine GABA serotonin acetylcholine endorphins inhibitory- excitatory inhibitory excitatory- inhibitory euphoria agitation paranoia sedation relaxation drowsiness depression sleep relaxation sedation mild euphoria excitation insomnia mild euphoria block pain slow respiration amphetamines, cocaine alcohol, Valium-type barbiturates LSD tobacco, nicotine narcotics

10. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.5

11. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.6 Schematic representation of the action of a synthetic enzyme. A precursor molecule and another chemical fragment both bind to the enzyme. The fragment has a tendency to connect with the precursor, but the connection is made much more likely because of the way the enzyme lines up to the two parts. After the connection is made, the new transmitter molecule separates from the enzyme.

12. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.7

13. © 2006 McGraw-Hill Higher Education. All rights reserved. Figure 4.8 Schematic representation of the action of a metabolic enzyme. The transmitter molecule binds to the enzyme is such a way that the transmitter molecule is distorted and “pulled apart”. The fragments then separate from the enzyme.

14. © 2006 McGraw-Hill Higher Education. All rights reserved. Chemical Theories of Behavior The Chinese made the yin and the yang.

15. © 2006 McGraw-Hill Higher Education. All rights reserved. Brain Imaging Techniques  PET-Position Emission Tomography  MRI- Magnetic Resonance Imaging