1. Neurons

2. Do Now
Do Now
How does this relate to the Nervous System?

3. Homework Due Today
Read Section 31.1
Answer question 1-3 on page 900

4. Homework Describe the function of the nervous system?
The functions of the nervous sustem are to collect information about the body’s internal and external environments, process that information and respond to it

5. Homework
Describe how your peripheral nervous system and central nervous system were involved in a simple activity you performed today.

6. Homework Name and describe the three types of neurons
Sensory neurons carry impulses from the sense organs. Motor neurons carry impulses from the brain and spinal cord to muscles and glands. Interneurons process the information from sensory neurons and send commands to other interneurons or motor neurons

7. Homework
The immune system of people with multiple sclerosis attacks myelin sheaths in the CNS. The myelin breaks down and scar tissue may result. How do you think this would affect the transmission of signals from the CNS?

8. Homework What happens when a neuron in stimulated by another neuron?
If the stimulus is grat enough, an impulse begins that travels rapidly along the axon toward the axon terminals, where the impulse may be passed on to other cells

9. Homework
How can the level of pain you feel vary if a stimulus causes and all-or-none response?
Although the response is all-or-none, the frequency of action potentials can vary depending on the strength of the stimulus

10. Homework Due Next Class
Finish Worksheet
Define:
Peripheral Nervous System
Central Nervous System
Axon
Myelin Sheath
Threshold
Synapse
Neurotransmitter

11. The Nervous System
The Nervous System

12. The Nervous System
The Nervous System responds to information collected from internal and external environments
Comprised of Peripheral Nervous System and Central Nervous System

13. Central Nervous System
Consists of the brain and spinal cord

14. Peripheral Nervous System
All nerves and supporting cells that collect information about the body’s internal and external environment

15. PNS/CNS
Constant communication is happening between the 2 nervous systems
You’re walking around in the dark and can’t see anything. Your hands are reaching for the light switch and your PNS relays the message of what it is touching to the CNS, which relays back to the PNS as to what it is supposed to be looking for.

16. Neurons
All impulses (messages) are transmitted by cells called neurons
Sensory
Motor
Interneurons
Process sensory information and send commands to other neurons

17. Structure of Neuron

18. Cell Body Largest part of a neuron
Houses the nucleus and most of cytoplasm

19. Homework Due Next Class
Finish Worksheet
Define:
Peripheral Nervous System
Central Nervous System
Axon
Myelin Sheath
Threshold
Synapse
Neurotransmitter