Neuro I Flashcards
function of the NS
controls and coordinates the body’s activities to maintain homeostasis
generation of sensory input to be processed
processing incoming data
generation of impulses that control voluntary and involuntary motor functions
storage of information
neurons
are the functional unit of the NS
cell body of neuron
main part of neuron, forms gray matter, center of the neuron
dendtites
recieve nerve impulses, branch like projections, carries impulses towards cell body
3 characteristics of a neuron
excitability
conductivity
influence
excitability
ability to generate an impulse
conductivity
ability to transmit an impulse within itself
influence
ability to influenec other neurons
axon
projects impulses away, found in myelin sheath
myelin sheath
speeds axon transmission, insulates & maintains white matter, nodes of Ranvier
axon with myelin sheath is myelinated or non myelinated
myelinated
multipolar neuron
multiple dendrites one axon
bipolar neuron
one dendrite, one axon
unipolar neuron
one process
lipid gives myelin what?
white color
insoluble in water-so need fat soluble Rx is needed to penatrate myelin sheath
classifications of neurons
structural-defined by the processes they have
functional-diretction of impulses conducted
sensory neurons
transmit nerve impulses toward CNS from peripheral sensory organs
Afferent-towards the brain (CNS)
motor neurons
transmit nerve impulses away from CNS to muscles, glands, organs
Efferent-away from CNS (brain)
Afferent
sensory neurons
Efferent
motor neurons
inter neurons
conduct impulses from one neuron to another
Sensory to motor or motor to sensory
two types of cells in the NS
neurons & neuroglia (glial) cells
Neuroglia cells
purpose: repair, support & protect neurons
more neuroglia than neurons
common source of primary tumors
types of neuroglia cells
astrocytes
ependymal cells
microglia