Nervous Tissue Flashcards
structural and functional unit of nervous system
neuron
most neuron cell bodies are located in _____
CNS
do not divide, although regeneration of axons possible
terminally differentiated
neurons that are not terminally differentiated
olfactory and hippocampus
part of neuron that contains nucleus and is surrounded by cytoplasm
soma
cytoplasm of neuron
perikaryon
rough ER of neruon
nissl substance
plasma membrane surrounding neural cell
neurilemma
highly branched neuron process
dendrites
area near soma where the axon arises
axon hillock
distal swelling where the axon terminates; contains mitochondria and membrane bound synaptic vesicles containing chemical neurotransmitters
terminal bouton
movement of products down an axon
axonal transport
____ axonal transport carries cytoskeletal elements
slow
____ axonal transport carries membrane bound organelles
fast
transport from cell body down an axon
anterograde transport
transport from axon to cell body
retrograde transport
anterograde transport uses ____
kinesin
retrograde transport uses ______
dyenin
most common type of neuron with several dendrites
multi-polar neuron
neuron type with single dendrite opposite axon
bipolar neuron
neuron type with no dendrites on soma, axon only
unipolar neuron
neuron type with single dendrite and axon fuse; soma is off to one side
pseudounipolar neuron
point where nerves is unresponsive to stimuli when Na channels close and can’t reopen for 1-2 millisecons
refractory period
terminal bouton separated from effector cell by ____
synaptic cleft
signaling molecules released from pre-synaptic molecule; diffuse across synaptic cleft, bind to receptor molecules on post-synaptic membrane
neurotransmitters
the 2 neurotransmitters used in PNS
acetylcholine and norepinephrine (adrenaline)
sympathetic response uses ________ as excitatory neurotransmitter (adrenergic)
noradrenaline (nor-epinephrine)
parasympathetic response uses ______ as excitatory neurotransmitter (cholinergic)
acetylcholine
provide structural and metabolic support for axons
Schwann cells
insulated by many concentric layers of plasma membrane from many schwann cells
myelinated nerves
several axons lie in channels within schwann cell, surrounded by a single later of neurilemma from schwann cell
non-myelinated nerve
gaps in myelin sheath between adjacent schwann cells that are responsible for rapid saltatory conduction
nodes of Ranvier
______ myelinate the CNS
oligodendrocytes
loose connective tissue that surround individual axons and schwann cells
endoneurium
surround multiple axons organized into bundles (fascicles); unique cells; exhibit epithelioid and myoid features that may play a role in axon regeneration
perineurium
additional layer of connective tissue that surround larger nerves containing several fascicles
epineurium
neurons with cell bodies in gray matter of brain and spinal cord in CNS
preganglionic neurons
neurons with cell bodies located within ganglia
postganglionic neurons
discrete aggregations of postsynaptic neuron cell bodies located outside the CNS; embryologically derived from neural crest
ganglia
surround each cell body that provide structural and mechanical support; derived from neural crest
satellite cells
_____ ganglia is located anterior to spine
prevertebral
_____ ganglia located primarily in the sympathetic truck
paravertebral
______ ganglia located in or near effector organ
parasympathetic
