1. The master communication center of the body.
The Nervous System
The master communication center of the body.

2. 12 pairs of cranial nerves
ANATOMY
Structural classification
CNS
Brain &
Spinal Cord
PNS
Cranial Nerves
& Spinal Nerves
12 pairs of cranial nerves
32 pairs of spinal nerves
CLICK HYPER LINK ON PICTURE FIRST
The parts of the nervous system can be classified based on structure or function
The structural classification is the Central nervous system the brain and spinal cord and the peripheral nervous system which include 12 pairs of cranial nerves and 32 pairs of spinal nerves

3. Our nervous system allows us to feel pain.
PHYSIOLOGY
3 Main Functions:
Monitor all information about changes occurring both inside and outside the body.
Process and interprets the information received and integrates it in order to make decisions.
Command responses by activating muscles, glands, and other parts of the nervous system.
Our nervous system allows us to feel pain.

4. Anatomy & Physiology
Draw the organizational flow chart showing the various parts of the nervous system and how they interact.
The central nervous system talks only to the peripheral nervous system
The peripheral nervous system deals with input which is collected by the sense organs like the eyes, ears, sensory cells in the skin. This is the sensory or afferent pathway.
The peripheral nervous system also deals with output which are commands sent to muscles or glands to illicit some kind of response like movement or secretion of a hormone. This is the motor or efferent pathway.
Reponses can further be broken down into two main types - Somatic which includes all the voluntary actions and Autonomic which are the involuntary responses.
Give me some examples of an autonomic motor response that is occurring in your body right now. – digestion the food we had for lunch, heart beating
Give me an example of a somatic motor response that you are doing right now. – writing, shifting in your seat
The autonomic pathway includes both sympathetic and parasympathetic divisions.
The sympathetic division typically deals with involuntary responses that stimulate or mobilize the body in extreme situations the fight or flight response is a good example of this.
The parasympathetic division typically deals with involuntary responses that calm and conserves energy the rest and digest response is a good example of this.

5. Anatomy & Physiology Sensory input Integration Motor output
Afferent pathway
Brain & spinal cord
Integration
Efferent Pathway
Motor output

6. Video clips

7. Sensory neuron (Afferent) relay neuron Motor neuron (Efferent)
Neurons
There are three kinds of neurons. Each is designed to carry out its job.
Sensory Neurons Carry impulses from receptors e.g pain receptors in skin to the Central Nervous Syystem ( brain or spinal cord)
Relay neurons relay impulses from sensory nerves to motor nerves.
Motor neurons carry impulses from central nervous syste, to effector e.g. muscle to bring about movement or gland to bring about secretion of hormone e.g ADH
Sensory neuron
(Afferent)
relay neuron
Motor neuron
(Efferent)

8. Mad, Mad, Mad scientist The Neuron Cell body Nucleus Axon
Draw a neuron in your lab book and label the dendrites, the axon terminals, the axon, the nucleus, cell body and myelin sheath. Then draw arrows to show the direction the impulse goes.
A nerve is an organ containing a bundle of neurons
Cell
body
Axon terminals
Dendrites
Nucleus
Myelin
sheath
Axon

9. Neuron Anatomy & Physiology
Extensions outside the cell body
Dendrites – conduct impulses toward the cell body
Axons – conduct impulses away from the cell body

10. Neuron Anatomy & Physiology
Myelin sheath wraps around the axon, allows impulses to travel very fast along the axon.
Nodes of Ranvier Gaps in myelin sheath along the axon

11. Neuron Anatomy & Physiology
Axons end in axonal terminals
Axonal terminals are separated from the next neuron by a gap called a Synaptic cleft
Synapse – a functional junction between nerves

12. Open your books to page 233
Draw a neuron and label
cell body dendrites nucleus axon terminal
schwann cell axon myelin sheath node of Ranvier

14. It’s what moves you!

15. Neuron Classification
Figure 7.6

16. Neurotransmitter is released from a nerve’s axon terminal
Crossing the Synapses
Impulses are able to cross the synapse to another nerve when the electrical signal changes to a chemical signal
Neurotransmitter is released from a nerve’s axon terminal
The dendrite of the next neuron has receptors that are stimulated by the neurotransmitter
The impulse is started again in the dendrite of the next neuron
The neurons are not touching each other, there is a space called a synapse that the signal has to cross it does with the use chemical and receptors. CLICK LINK

17. Impulse = Action Potential
If the action potential (nerve impulse) starts, it is propagated over the entire axon
Na+ enters the neuron (by diffusion) changing the charge along the outer axon from + to – and the charge inside the axon from – to +
K+ leaves the neuron (by diffusion) causing the charges along the inside and outside of the axon to revert back
The Na+ K+ pump restores the original configuration this action requires ATP

18. Starting a Nerve Impulse
A neuron at rest is polarized
Voltage dependent channels open allowing for the diffusion of Na+ into the neuron
Depolarization reversing the charges along the cell membrane
Na+ channels close and K+ channels open allowing K+ to diffuse out of the cell
Repolarization the charges along the cell membrane revert back to original

19. The Myelin sheath (formed by Schwann cells and oligodendrites) Why is it important?
Myelin sheath is provided by which two neuroglia cells? – Schwann and oligodendrocytes
Acts as insulation
Action potential occurs only at the unmyelinated regions called the nodes of Ranvier. This is where the sodium channels are located
Leap frogging from node to node allows the impulse to move very quickly along the axon
Myelin sheath has spaces = Nodes of Ranvier.
----The action potential jumps from node to node
Unmyelinated axon action potential speed = 10 m/s
Myelinated axon action potential speed = 120 m/s

20. Draw the action potential graph below.
Label: resting potential, repolarization, & depolarization 1 2 3 1 40 2 3
-70
Describe what is happening at points 1, 2, & 3

21. Action potential labs

22. Disease Multiple sclerosis destroys myelin sheaths.
Sodium (Na) channels are only at nodes.
Neuron can’t have an action potential or nerve impulse.
Disease that impact the myelin sheath, like MS, affect the action potential which impacts the action potential of that neuron. People with MS ultimately experience pain and decrease motor function in the areas of their body where the myelin sheath of the neurons has been effected.

23. Anesthetics = action potential
Local (Novocain, Xylocaine) attach to Na+ channel. Na+ can’t enter cell.
Anesthetia stops the action potential, stop the action potential and do you feel pain? – NO why? – the signal fro pain is stopped. Both local and general anesthesia prevent the change in polarity along the axis of the neuron.
General anesthetic (ether, chloroform) open K + channels, K + exits as fast as Na+ enters

24. The Reflex Arc
Reflex – rapid, predictable, and involuntary responses to stimuli
Reflex arc – direct route from a sensory neuron, to an interneuron, to an effector
Figure 7.11a

25. Types of Reflexes and Regulation
Autonomic reflexes
Smooth muscle regulation
Heart and blood pressure regulation
Regulation of glands
Digestive system regulation
Somatic reflexes
Activation of skeletal muscles

26. Reflex Arc

27. The Supporting Neurons
Neuroglia:
The Supporting Neurons
Each table will find information regarding a different type of “supporting” neuron to share with the class.
Each table has been assigned a cell type.
Use your book to fill in the requested information about the various Glial cells: Astrocyte, Microglia, Ependymal, Oligodendrocyte, and Schwann cells.
Select a representative to speak for your table – he or she must come up to the front of the class.
You have 7 minutes to gather the information.

28. (Neuro)Glial cells- why are they important?
Make up 85% of the nervous system
Clear away cellular debris
Microglia repair
Astrocytes create the blood brain barrier
Oligodendrocytes help with the myelin sheaths
Schwann cell 10