1. Do Now 1/7/15 Welcome back – happy 2015!
“Brain”storm: If you didn’t have a brain, what would you NOT be able to do? Write down at least 3 ideas.

2. Central Nervous System (CNS): brain and spinal cord.
Peripheral Nervous System (PNS): nerves of the body
        - 31 pairs of spinal nerves
        - 12 pairs of cranial nerves

3. Basic Divisions of the Nervous System
Figure 12.2

4. Motor Functions Somatic Nervous System - skeletal (voluntary)
Autonomic Nervous System -  smooth muscles, glands (involuntary)

5. THREE BASIC FUNCTIONS OF THE NERVOUS SYSTEM
Sensory -  receptors gathers info from stimuli
Integration - information is brought together
Motor - responds to signals, homeostasis

6. Create your own example with a partner
Sensation?
Integration?
Response?
Create your own example with a partner

7. The Neuron Neurons = masses of nerve cells that transmit information
Cell Body - contains the nucleus and two extensions
Dendrites – shorter, more numerous, receive information
Axons – single, long “fiber” which conducts impulse away from the cell body, send information

8. Types of Neurons (Functional)
Sensory neurons – transmit impulses to the spinal cord and brain from all parts of the body
- also called afferent neurons
Motor neurons – transmit impulses away from the spinal cord and brain to muscles and tissue
- also called efferent neurons
3. Interneurons – conduct impulses from sensory neurons to motor neurons
S.A.M.E.
Sensory = Afferent
Motor = Efferent

9. Neurons Classified by Function: Sensory vs. Motor Neurons
Figure 12.11

10. Types of Neurons (Structural)
Structural: (A) Bipolar (B) Unipolar (C) Multipolar
Prefix related to number of extensions

11. Interesting Characteristics about the Neuron
Longevity – can live and function for a lifetime
Do not divide (Amitotic) – fetal neurons lose their ability to undergo mitosis; neural stem cells are an exception
Excitability – neurons respond to stimulation
Conductivity – electrical changes can travel through a neuron
Secretion – neurotransmitters (NT) are released

12. glia means glue Neurons are not the only type of nervous cell
Glial cells provide support for the neurons.
glia means glue
Behind every successful neuron is an “army” of even more awesome glial cells.

13. Type of Glial Cell
Description
Location
Microglia
Oligodendrocyte
Schwann Cell
Astrocyte

14. Glial Cells - support cells for the neurons
1.  Microglia: scattered throughout the CNS, digest debris or bacteria
Microglial cells respond to immunological alarms

15. Glial Cells 2. Oligodendrocytes: makes the myelin sheath that
provides insulation around the axons in the CNS

16. 3.  Schwann cells:  form the insulating myelin sheath around the neurons in the PNS
       

17. 4. Astrocytes: connect blood vessels to neurons in the CNS
I connect to blood vessels

18. Supporting Cells- NEUROGLIA

19. - these serve as insulation around the axon
MYELIN SHEATHS
- these serve as insulation around the axon
Schwann cells supply the myelin for peripheral neurons,
Oligodendrocytes myelinate the axons of the central nervous system.

20. Function of Myelin Sheaths
Myelin allows the neuron to send impulses quicker
The nerve fibers of newborns are unmyelinated - this causes their responses to stimuli to be course and sometimes involve the whole body.  Try surprising a baby!

21. White vs Grey Matter
Myelinated (white matter) – myelinated axons
Unmyelinated (grey matter) - unmyelinated

22. Additional structures of a neuron
Myelin -insulation surrounding axons
Nodes of Ranvier - gaps in the insulation
Terminal buttons – the “buttons” at the end of the axon

23. The Synapse Synapse - junction between two communicating neurons
Nerve pathway - nerve impulse travels from neuron to neuron
Dendrite → cell body → along axon -> synapse (gap) → dendrite

25. Labeling a Neuron Axon Axon Hillock Cell Body Dendrite Myelin Sheath
Nodes of Ranvier
Nucleus
Synapse
Terminal Buttons

26. Resting Membrane Potential
-70 mV

27. Cell Membrane Potential