1. Intro to the Nervous System 9(a)

2. Organization of the Nervous System Central Nervous System (CNS) – Includes the nerves of the brain and spinal cord. Peripheral Nervous System (PNS) – All other nerves through the body.

3. Basic Functions Sensory – Sending a signal towards the brain. – How many different types of senses do humans have? Five: ( Vision, hearing, tasting, smelling, touching) Integrative – Processing signals in the brain or spinal cord. Motor – Sending a signal from the brain to perform an action in the muscles or glands.

4. Nerve Cells Neuron – The basic nerve cell. – Soma – The cell body of a neuron. – Dendrites – The input and sensors of a neuron. – Axon – The output shaft. Neurons have only one axon, but can be branched to connect to other neurons. The axon is coated by a wrapping of Schwann cells. This is called the myelin sheath. The thickness of the myelin sheath determines how fast a nerve impulse will be.

6. Nerve Cells Neuron – The basic nerve cell. Label the following: soma, axon, dendrites, Schwann cells, myelin sheath, axon hillock, nucleus, nodes of ranvier Draw arrow showing direction of a nerve impulse.

8. Types of Neurons Unipolar neuron – Second most common neuron; located in the peripheral nervous system. – Primarily relays sense of touch to and from the brain. – These neurons can be as long as the tip of the finger to the spinal cord! – Diagram:

9. Types of Neurons Bipolar neuron – Most rare type of neuron; located only in certain places. – Specialize in transmission of special senses: Smell (olfactory) Vision (rods & cones) Hearing & balance Taste – Diagram:

10. Types of Neurons Multipolar neuron – Most common neuron; located in the central nervous system. – Has many dendrites, which allow many interneural connections. – Diagram:

11. Pop-Quiz

15. Assignment Draw and label a clean sketch of a neuron. Use straight lines (use a ruler) when labeling. Color when completed. Make sure the following parts are labeled (write small): – Soma, dendrites, axon, axon hillock, nucleus, myelin sheath, Schwann cell, nodes of Ranvier Once labeled, write a simple definition next to each label. On the backside of the drawing, define the additional vocab terms written on the white board (may use phone or book if necessary):

16. Vocabulary 1)Neuron 2)Neuroglia 3)Central Nervous System 4)Peripheral Nervous System 5)Sensory Neuron 6)Motor Neuron 7)Neurotransmitter 8)Synapse 9)Action Potential 10)Resting Membrane Potential