Topic 10 Nervous System Basics

Central Nervous System Peripheral Nervous System Divisions of the N.S. Central Nervous System Processes & stimulates Peripheral Nervous System Nerves Three Functions: Sensory Integrative (associational) Motor Accelerator or inhibitory

11.1

Descriptive parts & terminology 11.2.1

Other terms: Synapse Neurotransmitters Nerve vs neuron Impulse

Anaxonic Brain & some senses Bipolar From sense organs Neuron classification Anaxonic Brain & some senses Bipolar From sense organs 11.3+

Unipolar Most sensory neurons Long Multipolar In CNS Interneuron & Motor

11.3+

Schwann cells Neuroglia PNS Stabilizes Shields from… Neurilemma Myelination Lipid membrane sheath Internode 11.5(1-3)

Distal end deteriorates WBC Schwann cells proliferate Schwann cells assist in repair Injury Distal end deteriorates WBC Schwann cells proliferate Nerve Growth Factor 11.5.4

Cuboidal/columnar cells Between interstitial fluid & CSF Neuroglia classification Ependymal cells Cuboidal/columnar cells Between interstitial fluid & CSF Produce, monitor, circulate 11.4

Microglia Structural support Phagocytic

Astrocytes Blood-brain barrier…transport Structure Induces synapse formation Mops up excess…

Oligodendrocytes Structure Myelin sheath

Satellite cells Supports ganglia Regulate environment

Resting potential- potential for electrical work 11.7.2

Electrochemical gradient More permeable to K+ 11.7.3

11.7.3

Opens only with specific chemical Ex. ACh at NMJ Types of Gated Channels Opens only with specific chemical Ex. ACh at NMJ Dendrites & cell bodies 11.8.1

Membrane capable of conducting action potentials Stimulated by change in potential Ex. Na+, K+, Ca+2 gated channels 11.8.2

Distortion of membrane surface Ex. Sensory receptors 11.8.3

11.9(1-3)

11.10.1

All-or-None Response Will respond or not at all Stimulus may become more frequent

Refractory Period Immediately following an action potential, the membrane can not be triggered by a threshold stimulus. 11.10.2

Impulse conduction Like dominos Unmyelinated Slower . 11.11.1

Impulse conduction Myelinated Faster Diameter α speed 11.11.2

Synapse terms 11.2.2

11.2.3

Transmission . 11.12.2

11.12.1

Excitatory or inhibitory Ex. Neurotransmitters Excitatory or inhibitory Ex. ACh Serotonin Endorphins Dopamines

11.13.3

Neuronal pools… Convergence Collects/process Divergence Impulse processing Neuronal pools… Convergence Collects/process Divergence Amplifies impulse

11.13.2