Neurons Flashcards
parts of a neuron
dendrites
soma
axon
synaptic bouton
glial cells
non-neuron cells in the nervous system that perform a range of supporting functions to ensure an optimal environment for neurons
types: oligodendrocytes, Schwann cells, astrocytes, microglia
astrocytes and microglia
form blood/brain barrier
control chemical regulation of space between neurons
rid of metabolic waste and scar tissue
oligodendrocytes
provide physical support and electrical insulation (myelin)
Schwann cells
insulate peripheral nerves (myelin)
functions of the nucleus of a neuron
portein and neurotransmitter manufacturing
functions of microtubules in neurons
form skeleton
transport
resting potential
stored energy
necessary for neurons to receive information
typically -60 to -70 mV
creating by the movement of ions, electrical gradient, and the Na+/K+ pump
movement of ions through the membrane (inside or outside?)
Na+: outside
Cl-: outside
K+: inside
A- (proteins): inside
electrical gradient
similar charges repulse each other
negative charges inside retrains K+ and Cl- movement
Na+/K+ pump
active mechanism
ejects 3 Na+ ions for every 2 K+ pulled in
makes the inside of a neuron more negative
action potential
unit of information
electrically transmitted
occurs in an all-or-none way
travels faster in thicker neurons
steps on an action potential
- Na+ gates open
- Na+ gates close after ~0.5 msec
- Na+ gates cannot reopen for 1 msec
- K+ gates open, resting potential is restored
types of coding information for action potentials
frequency code: the number of action potentials
labeled line code: each neurons codes different types of information
absolute refractory period
occurs after Na+ gates close
prevents an action potential from reversing direction and collision
sets limits and constraints on coding of information
