Chapter 48
Nervous System Overview
Purpose – receive information
from environment (exterior) and
interior of organism
Information flow path sensors, input, integration,
motor output, effector
CNS vs. PNS
Electrical vs. chemical
Saltatory Conduction
•What is myelin, structure/function
•Schwann cells
•Nodes of Ranvier
•Why does a myelin sheath speed
up the signal/impulse?
•Where does depolarization occur in
myelinated neuron?
Signal Propagation
•Graded potentials vs. action
potential
•Depolarization, repolarization,
hyperpolarization (what is
undershoot?)
•Absolute and relative refractory
period differences
•Know graph of action potential
including resting and threshold
values in mV
Synapses
 Chemical signal vs. electrical.
Action Potential
Know steps in transition from
resting potential to action
potential and return to resting
Flow direction and gradient of
ions (Na+, K+) across
membrane that leads to action
potential and restores resting
potential.
Roles of channel proteins,
voltage gated channels and
sodium/potassium pump
Nervous System
Neuron
•How does form follow
function?
•Dendrite, soma, axon,
synaptic terminals
•Pre-synaptic neuron vs. postsynaptic
•What direction does impulse
travel (dendrite end to synaptic
terminal end).
Steps leading to release of
neurotransmitter – action potential,
Ca channels open, Ca flows into
synaptic knob, vesicles fuse to
membrane, neurotransmitter
released into synapse
How does neurotransmitter
interact with receptor proteins
(ligand)?
How are neurotransmitters
disrupted by neurotoxins
Know function of specific
neurotransmitters mentioned in
notes
Fate of used neurotransmitters