1. Anatomy and Physiology
Nervous System Notes

2. Organization of the NS Central Nervous System (CNS)
Brain
Spinal Cord
Peripheral Nervous System (PNS)
31 pairs of spinal nerves
12 cranial nerves

3. Functions of the NS Sensory Motor Integrative / Association
gathers info about changes occurring within and around the body - Sensory receptors, at ends of peripheral nerves send signals (nerve impulses) to the CNS. Sensory Neuron
Motor
responses to signals (impulses). Signals sent from the CNS to effectors (muscles or glands). The goal is usually to maintain stable conditions (especially internal) – Homeostasis. Motor neurons.
Somatic Nervous System (voluntary skelteal muscles)
Autonomic Nervous System (involuntary smooth muscles; glands)
Integrative / Association
information is “brought together,” interpreted, to create sensations, create thoughts, add to memory, make decisions, etc. Association neuron or interneuron

4. Cells of the NS Neuronal Non-Neuronal (Neuroglial/Glial Cells)
Neurons (pictured here)
Conduct action potentials (nerve impulses)
Non-Neuronal (Neuroglial/Glial Cells)
Supportive Cells
Astrocytes
Ependymal Cells
Microglial Cells

5. Glial Cells 1. Astrocytes
- Forms tight junctions between endothelial cells of capillaries to form Blood-Brain-Barrier
BBB:
- Exchange sight for
-Nutrients
-Wastes
- Ultimate protection layer
around brain & spinal cord

6. Glial Cells 2. Ependymal Cells - secrete Cerebrospinal Fluid (CSF)
within the ventricles of the brain

7. Glial Cells 3. Microglial Cells
- Phagocytic (engulf/eat) in response to inflammation
-Necrotic (dead) tissue
-Bacteria
-Foreign substances

8. Glial Cells 4. Oligodendrocyte - form the myelin sheath in CNS
- Insulates neurons, speeding up the rate of the action potential
- Involved in many neurodegenerative problems:
- MS (multiple sclerosis)
- ALD (adrenoleukodystrophy)
- ALS (Lou Gehrig’s Disease)

9. The Neuron Dendrites Cell Body Axon Myelin Sheath Presynaptic Knobs
Direction of Nerve Impulse

10. The Synapse -Pre & Post synaptic membranes -Synaptic Cleft
-Synaptic Vesicles
-Neurotransmitters
(Ex: acetylcholine,
nor-epinephrine, dopamine,
serotonin)