1. The “Control Systems” of the Body
Local Control
Autocrine -
Paracrine -
Long Distance Control
Endocrine System
Slower Response, Broad, Long Lasting
Nervous System
Faster Response, Specific, Brief

2. The Nervous System Overview Neurophysiology Central Nervous System
Peripheral Nervous System
Autonomic N.S.
Somatic N.S.

3. Overview of the Nervous System

4. PNS CNS Sensory Pathway Receptors Interneuron (Integration)
1. Sensory Neuron
Interneuron
(Integration)
2. Interneuron
3. Motor Neuron
Motor Pathway
Effector
Tissue

6. 3 Types of Functional Neurons:
1) Sensory (in)
2) Interneurons (processing)
3) Motor (out)
Which neuron is
the most numerous?

7. Dendrites Cell Body Axon Axon Terminal (with End Bulb)
A Typical Neuron
Dendrites
Cell Body
Axon
Axon Terminal
(with End Bulb)
incoming info.
integration of info.
Nodes of
Ranvier
outgoing info.
release of neurotransmitter

8. Equilibrium Potentials:
- Na+
- K+
Resting Membrane Potential (RMP) for cells

10. Graded Potentials Action Potentials
Localized change in membrane potential that varies
in magnitude and is decremental.
Action Potentials
Rapid reversal in membrane potential (due to changes in ion permeability), with constant magnitude and is non-decremental.

12. Action Potentials "All or none" event
Signal does not diminish over distance
There are 4 Phases in an Action Potential:
1. Threshold
2. Depolarization
3. Repolarization
4. Hyperpolarization

15. Refractory Periods Absolute Refractory Period:
Relative Refractory Period:

16. Summation of Graded Potentials
Temporal Summation:
As the frequency of a single stimuli increases, the changes in membrane potential can be added and its magnitude can increase.
Spatial Summation:
As multiple simultaneous stimuli occur at different places on the neuron, the changes in membrane potential can be added and its magnitude increased or decreased.

19. Graded vs. Action Potentials
1. Magnitude varies
1. No variation - All or None
2. Decremental
(passive spread)
2. Non-decremental
(self-regenerating)
3. No Refractory Periods
in Graded Potentials
3. Two Refractory periods:
Absolute and Relative
4. Summation is possible
4. No Summation possible
5. Trigger: NT's, hormones
5. Trigger: Threshold
6. Occurs at cell body
(direction can vary)
6. Occurs at axon hillock (one way direction)

20. How fast can a signal travel down an axon?

21. Speed of Conduction of Signal
Small Diameter
Large Diameter

23. Speed of Conduction of Signal
Small Diameter
Large Diameter
Vs.
2. Temperature
3. Axon Myelination

26. The Biochemistry of the Synapse

27. 2 ways the Post-Synaptic cell Responds

28. Post-Synaptic Cell Responses
Ionotropic Effect
Metabotropic Effect

29. Stopping Signal Transmission
Stop the Impulse (Stop Pre-Synaptic AP)
Clear Away the Synaptic Cleft
1. Diffusion away from Receptors.
2. Enzymatic Degradation of NT.
3. Re-uptake of NT by Pre-Synaptic cell.

30. Clearing up the synaptic cleft

31. Degrading NT’s into non-stimulating fragments
and Recycling into pre-synaptic neuron.

32. Agonists:
Signal molecules that bind the receptor and induce
the post-receptor events that lead to a biological
effect. They act like the normal or true ligand (signal
molecule), though potency may vary.
Antagonists:
Signal molecules that bind the receptor and block
binding of the true ligand or agonist, and fail to trigger
intracellular signaling events.

34. Agonists
Antagonists

35. Benzodiazepines are tranquilizers.
e.g. Valium (diazepam) and Xanax (alprazolam), etc. for anxiety, insomnia…

36. Yum Yum Foods that Stimulate GABA Production in CNS: Almonds Bananas
Beef Liver
Broccoli
Brown Rice
Green Tea
Halibut
Lentils
Oats, whole grain
Oranges, citrus fruits
Rice bran
Spinach
Walnuts
Yum
Yum

37. Neuronal Pathways
Divergent:

38. Neuronal Pathways
Convergent:

39. Pre- and Postsynaptic Inhibition and Facilitation
The Presynaptic terminal
Inhibitory neuron(s) – less NT released
Excitatory neuron(s) – more NT released
The Postsynaptic membrane and receptors
- Receptor numbers
- Degradation rates
- Permeability

41. The 6 Different Glial Cells

42. 2 Glial Cells of the PNS
1. Schwann cells – create the myelin sheath for axons in the
PNS. Many Schwann cells help to myelinate axon.
2. Satellite cells - small cells that surround neurons ganglia in PNS. Act to protecting and repair ganglia.

43. 4 Glial Cells of the CNS
3. Oligodendrocytes - create the myelin sheaths of axons in
CNS, providing insulation, allowing signals to propagate faster.
4. Astrocytes – help create the restrictive blood-brain barrier
(BBB), to protect delicate nervous tissue.
5. Microglia - phagocytic (like macrophages), acting as defense
cells in CNS. Cells multiply if CNS is damaged or infected.
6. Ependymal cells - line fluid cavities of the CNS (e.g. ventricles and central canal). They help create and secrete cerebrospinal fluid (CSF).