Becker Exam I Flashcards
oligodendrocytes
location:
function:
CNS
myelinate axons in the CNS & uptake neurotransmittes
astrocytes
location:
function:
CNS
maintain NT concentration, contribute to BBB tight junctions, borders brain surface, create scares, information network
microglia
location:
function:
CNS
immune cell of CNS, active/phagocytize/APC
Ependymal cells
location:
function:
CNS
lines ventricles, choroid plexus, and central canal of spinal cord
- simple cuboidal cilia = ventricles
- simple cuboidal no cilia = choroid plexus
- simple columnar = central canal
schwann cells
location:
function:
PNS
myelinate axons in the PNS & support unmyelinated axons
satellite cells
location:
function:
PNS
surround neuronal cell bodies
4 functional zones of neurons
dendritic zone
cell body/soma
axonic zone
telodendritic zone
3 types of neurons
bipolar
pseudounipolar
multipolar
Define the differences between bipolar, pseudounipolar, and multipolar neurons and where they are each typically found in the body.
bipolar - sensory, special senses
pseudo unipolar - sensory, cranial, and spinal sensory ganglion
multipolar - most neurons, eccentric nucleus
Describe what zone of a neuron contains signal receptors and the three different types of receptors classified by location.
dendritic zone
exteroceptors: external stimuli (vision, auditory, olfaction, taste, skin)
interoceptors: viscera, internal stimuli
proprioceptors: tendon organs & neuromuscular spindles
Explain the differences in how oligodendrocytes achieve myelination as compared to neurolemma (Schwann) cells and where each cell type is located in the body.
Schwann cells (PNS) myelinate one segment of one axon
oligodendrocyte (CNS) myelinates several axon segments
Describe saltatory conduction and identify nodes and internodes.
Saltatory conduction: speeds the conduction of the action potential
Explain how myelination and axon diameter effects the conduction velocity of the action potential.
Increase in diameter = decreased resistance = increase in velocity
Increase in myelination = increase in conduction velocity
difference between small-diameter axons and large-diameter axons in terms of conduction velocity
small diameter = slow, unmyelinated, pain
large diameter = fast, myelinated, proproception
parts of NMJ
telodendria
synaptic cleft
motor end plate
define motor unit
motor neuron + axon + NMJ + all the fibers it innervates
white matter
glial cells & myelinated axons fiber tracts
gray matter
neuronal cell bodies, dendrites, initital segment of axons (unmyelinated), glial cells, synapses
neuropil
network of axons, dendrites, neuroglial and synapses
Identify and describe the flow of signaling in the gray matter layers of the cerebellum.
granular layer –> molecular layer –> purkinje layer
Describe the composition of the blood-brain-barrier.
endothelial tight junctions
continuous basement membrane
astrocytic end feet on blood vessels
Define a nucleus in relation to the brainstem’s organization.
functional clusters of neuron cell bodies in the brainstem
Explain the composition and function of the choroid plexus.
Composition: cuboidal ependymal cells with microvilli, fenestrated capillaries, c.t.
Function: Produces CSF
sensory ganglion
receive signals from PNS –> CNS
central nucleus
more satellite cells
psuedounipolar neurons
no synpases
dorsal root ganglia & cranial ganglia
Cr.n. II and VII
motor ganglion
eccentric nucleus
less satellite cells
multipolar neurons
many synapses
sympathetic & parasymp ANS
myenteric plexus ENS
3 layers of c.t. are found in a peripheral nerve
epineurium
perineurium
endoneurium
