Nervous system Flashcards
Dendrites
(little trees)
- Short, highly branched structures that conduct impulses toward the cell body.
axon
Single process (projection) of the neuron that carries an electrical signal (action potential) away from the cell body towards a target cell.
anterograde transport
transport of substances AWAY from the cell body towards axon terminals
retrograde transport
transport of substances from the axon terminals TOWARDS the neuron soma or cell body.
BBB (blood brain barrier)
physiological barrier between the circulatory system and the central nervous system that establishes a privileged blood supply, restricting the flow of substances into the CNS
Leakage channels
Ion channels that randomly open and close, allowing slow, continuous diffusion of ions
Voltage-gated channels
Ion channel that opens because of a change in the charge distributed across the membrane nearby
Ligand-gated channel
ion channel that opens upon neurotransmitter binding
Mechanically-gated channel
ion channel that opens when a physical event directly affects the structure of the protein
Action Potential
change in voltage of a cell membrane in response to a stimulus that results in
transmission of an electrical signal; unique to neurons and muscle fibers
Voltage
AKA “ Potential Energy”
is the difference in electrical charge between two areas
Resistance
Property of electricity by where the current is impeded in some way
RMP
Resting Membrane Potential:
the difference in voltage across a cell membrane under steady state conditions, typically -70 mV
Depolarization
change in a cell membrane potential from rest toward zero
Polarized
the state whereby the inner membrane is negatively charged compared to the outer
(when at RMP)
Repolarization
return of the membrane potential to RMP after depolarization
IPSP
Inhibitory Post Synaptic Potential
- hyper polarizing graded potentials in the postsynaptic membrane
EPSP
Excitatory Post Synaptic Potential
graded potential in the postsynaptic membrane that is the result of depolarization and makes an action potential more likely to occur
Somatic Nervous System
Voluntary portion of the peripheral nervous system.
grey matter
regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter
white matter
regions of the nervous system, usually referencing the CNS, containing mostly myelinated axons which makes the tissue appear white due to the high lipid content
Denticulate Ligaments
Lateral extensions of the pia mater that stabilize the spinal cord in the vertebral canal
dorsal roots
Axons entering the posterior horn of the spinal cord
ventral roots
Axons emerging from the anterior or lateral horns of the spinal cord
