1. Review: The Nervous System Mr. Yassin 07-08-14

2. Lesson Intention: Introduction The nervous system: –Structural component –Physiological functions Reflex Arcs: -Knee Jerk Reflex Activity: Simulating a reflex arc Review Test/Answers Homeowork

3. Components: The nervous system is composed of 2 parts: 1.Central Nervous System: -Consists of the brain and spinal cord. Its function is to interpret external environments and internal organ systems through complex neuronal connections that elicit reactions. 2. Peripheral Nervous System: -This consists of nerves and ganglia (cluster of nerve cells) that lie outside of the brain and spinal cord. Effectively, it functions as a messenger between organ systems and the central nervous system.

4. Neuron: The main unit in the nervous system.

5. 1.Dendrites: receive nerve transmission from other neurons via the action of neurotransmitters. 2. Cell Body (soma): This is where that message is transmitted to. 3. Nucleus: contains all the genetic material (DNA) 4. Axon: transmits information to other neurons

6. 3 Different Types of Neurons: 1.Sensory Neuron (unipolar):  Transmit nerve impulses from receptor sites to the CNS. 2.Interneuron (bipolar):  Function as go-between neurons that facilitate the transmission of impulses. 3.Motor Neuron (multipolar):  They transmit impulses from the central nervous system to muscles and glands that elicit a reaction.

8. The 3 neuron examples exist within an interconnected network of neurons that transmit information to and from each other. A reflex arc is a simple example of how these cells work together to elicit a reaction – autonomic (involuntary control) Reflex Arc: Knee Jerk Reflex

9. Stimulus Receptor Sensory Neuron Brain and Spinal Cord CNS Motor Neuron Effector Muscle or gland Response INPUTS OUTPUT The nervous system in action

10. Action Potentials: Release of a neurotransmitter usually follows arrival of an action potential at the synapse. How an action potential works: http://www.youtube.com/w atch?v=ifD1YG07fB8

11. Activity: We’re going to simulate a reflex arc. Line up at the back of the room. ROLES: –3 people to be receptors –4 people to be sensory neurons –2 people to be interneurons –1 person as the brain – 2 Motor Neurons – 3 Effectors

12. Review Test: -Have 15 minutes to complete it. -Formal -Attempt it individually

13. What you should know: The 3 main types of neurons and their structure. The process of a reflex arc and examples. The nature of action potentials and the role of neurotransmitters in that process.

14. HOMEWORK: -Complete questions from the Biozone Student workbook. 1. Neuron Structure and Function (p. 282) 2. Reflexes (p. 285)