This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Action Potential Propagation (cont’d)
• The spread of excitability in a neuron
is directional Fig. 4‐9a, p. 97 Fig. 4‐8, p. 95 Action Potential Propagation (cont’d)
Contiguous Conduction Fig. 4‐9, p. 97 Action Potential Propagation (cont’d)
Saltatory Conduction & Myelination
• Composed of lipids
• Two types of glia
• Schwann – PNS
• Oligodendrocytes - CNS
• Nodes of Ranvier
• Gaps between myelin
Fig. 4-12, p. 100 Action Potential Propagation (cont’d)
Saltatory Conduction & Myelination Fig. 4-13, p. 101 Action Potential Propagation (cont’d)
Comparing Contiguous & Saltatory Conduction
Conduction Velocity 1.Resistance
↑ diameter = ↓ resistance = faster
• Fewer leaks = faster 3.Capacitance
More insulation = faster Saltatory Conduction is Faster
• APs only regenerated at nodes
• Conduction is ~ 50X faster
than seen with contiguous
conduction. Neuron-to-Neuron Communication:
The Chemical Synapse Each cell might have many
inputs and/or many outputs Neuron-to-Neuron Communication:
The Chemical Synapse – a closer look Fig. 4-15, p. 105 Neuron-to-Neuron Communication:
Binding the postsynaptic receptor THINK OUTSIDE THE BOX !!
What might cause an EPSP? What might cause an IPSP Fig. 4-16, p. 106 Neuron-to-Neuron Communication:
Summation of inputs Fig. 4-17, p. 109 ...
View Full Document
This note was uploaded on 11/24/2011 for the course NPB 97952 taught by Professor ? during the Spring '09 term at UC Davis.
- Spring '09