Nervous System Flashcards
What is a soma?
contains nucleus & most organelles
What are dendrites?
reception of incoming info
What does the axon do?
transmits action potentials
What is the axon hillock?
where the axon originates & action potentials initiate
What does the axon terminal do?
release neurotransmitter
Bipolar neuron
2 neurites
Pseudounipolar neuron
one connection
Multipolar
99% of neurons
Afferent neuron
info from outside to CNS
Efferent neuron
CNS to effector
What do glial cells do?
provide neuron support
4 types of glial cells
astrocytes
microglia
oligodendrocytes
Schwann cells
Anterograde transport
kinesin proteins, from soma to axon terminal
Retrograde transport
dynein proteins, from axon to some
Are leak channels always open or closed?
always open
What has the greatest effect on resting membrane potential?
Na/K pump
What does resting membrane potential depend on?
intracellular & extracellular Na+ & K+ concentrations
permeability
What is the equilibrium potential for Na+?
+60 mV
What is the equilibrium potential for K+?
-94 mV
What is the resting membrane potential?
-70 mV
What distance do graded potentials communicate over?
short distances; communication within the neuron
What distance do action potentials communicate over?
long distances; communication throughout the body
How is the amplitude of a graded potential dependent on?
the strength of the stimulus
What do graded potentials determine?
whether or not an action potential will occur
What is the excitatory phase of a graded potential?
depolarization
What is the inhibitory phase of a graded potential?
hyperpolarization
What happens with the addition of 2 graded potentials?
a higher depolarization & an action potential are produced
What do action potentials travel along?
axons
When does the Na+ channel activation gate open?
threshold & depolarization
When does the Na+ channel inactivation gate open?
depolarization
When does the Na+ channel inactivation gate close?
repolarization
