2. Biology and Behavior The Nervous System is our bodies “Blueprint”: – It gathers & processes information – Responds to stimuli – Coordinates the workings of different cells – Regulates our internal functions Nervous System is involved in psychological processes such as: - thought - movement - emotion - sensation

3. Nervous System: The Building Blocks Neurons (nerve cells) are the basic units of the nervous system Location  They run throughout our whole body! Purpose  communicate with one another by sending & receiving messages from the structures of our body Held in place & fed by Glial Cells: - provide nutrition, support, & insulation to neurons

4. Nervous System: The Building Blocks Types of Neurons: – Motor  send information onward to control muscles – Sensory  bring senses in from other senses – Associative  provide links between neurons

5. Structure of a Neuron Cell Body (Soma): directs actions of the cell Nucleus: contains genetic material for the cell Dendrites: enables neuron to receive information Axon: carry electrical signals (messages) out of the cells, sends a chemical message to adjacent neurons via Axon/Terminals Myelin: insulates & protects Axons w/a fatty substance

6. Nervous System: Communication The Process of Communication: – In order for message to be sent from one neuron to another… must cross a Synapse junction between dendrites via Axon Terminals (where communication takes place)

7. Neurons send messages across synapses (junctions) by releasing… Neurotransmitters  chemicals stored in sacs in the axon terminals (look like “buttons”) Nervous System: Communication

8. Fives Main Types of Neurotransmitters: Nervous System: Communication  Serotonin – affects mood, sleep, sensory perception, and other functions, may play a role in psychological disorders like depression  Acetylcholine – involved in memory, muscle action, sleep, emotions, those w/ Alzheimer’s have lower levels  Dopamine – affects movement, attention, memory, learning, plays role in addiction  Norepinephrine – affects learning, memory, emotions, eating, alertness, etc.  Epinephrine – emotions, memory storage

9. Neurons are Communicating

10. Nervous System: Two Main Parts

11. Part 1: Central Nervous System – Consist of  brain & spinal cord – Function  receives, processes, interprets, and stores sensory information Responsible for Spinal Reflexes: - automatic & require no conscious effort - Ex: touch something hot and immediately remove hand

12. Nervous System: Two Main Parts Part II: Peripheral Nervous System – Consist of  all parts of the nervous system outside the brain and spinal cord – Function  handles the central nervous system’s input & output Sensory Nerves: - carry messages from receptors to brain Motor Nerves: - carry messages from CNS to muscles, glands, and internal organs

13. Somatic Nervous System – Controls skeletal muscles – Permits voluntary actions Autonomic Nervous System – Regulates body’s vital functions (blood vessels, internal organs) – Permits self-regulating actions – Has two divisions:

14. Parasympathetic System: - calms & relaxes the body - Ex: Feel sick to your stomach

15. Sympathetic System: - mobilizes body for action - increases energy output - Ex: Fight or Flight