The Nervous System Flashcards
Neurons
Specialized cells capable of transmitting electrical impulses and translating them into chemical signals
Anatomy of Neuron: Cell Body/Soma
where nucleus is located
location of endoplasmic reticulum and ribosomes
Anatomy of Neuron: Dendrites
appendages coming off of the soma that receive signals
Anatomy of Neuron: Axon Hillock
info from dendrites passes through cell body and is integrated here
Action Potentials
transmission of electrical impulses down the axon
Signals arriving from the dendrites can be ____ or _____ , the axon hillock sums these signals and if it reaches _____ , to initiate an action potential.
excitatory
inhibitory
threshold
Anatomy of Neuron: Axon
long appendage that terminates in close proximity to target (muscle, gland or neuron)
Anatomy of Neuron: Myelin Sheath
insulation across nerve to prevent loss/crossing of signals and increases speed of conduction
Oligodendrocytes
CNS cells that produce myelin
Schwann Cells
PNS cells that produce myelin
Anatomy of Neuron: Nodes of Ranvier
breaks in myelin sheath on axon for rapid signal conduction
Anatomy of Neuron: Nerve Terminal/Synaptic Bouton
enlarged and flattened terminal area to maximize neurotransmission and ensure proper release of neurotransmitters
Anatomy of Neuron: Synaptic Cleft
space between neurons where axons release neurotransmitters to dendrites of next neuron
Anatomy of Neuron: Synapse
Nerve Terminal, Synaptic Cleft, Postsynaptic Membrane
Nerve
multiple neurons may be bundled together in the peripheral nervous system
can be sensory, motor or mixed
Cell bodies of neurons of the same type are clustered together into _____
ganglia
In the CNS, axons may be bundled together to form _____ , which cary only one type of information.
tracts
The cell bodies of neurons in the same tract are grouped into _____
nuclei
Glial Cells/Neuroglia
other cells that support neurons
Astrocytes
form blood/brain barrier, nourish neurons by controlling solute transport between nervous tissue and blood
Ependymal Cell
line ventricles of brain and produce cerebrospinal fluid to support brain as a shock absorber
Microglia
phagocytic cells that ingest and breakdown waste products in CNS
Resting Membrane Potential
all neurons have this, the electrical potential difference between the inside and outside of the neuron
usually -70mV
inside of neuron is negative to the outside
Na+ /K+ ATPase
channel that maintains the membrane potential of the neuron
moves 3Na+ out of cell for every 2K+ into the cell
Inside the neuron ____ is high and ____ is low. Outside the neuron, ____ is high and ___ is low.
[K+} , [Na+]
[Na+], [K+]
Negative resting potential is generated by both ________ within the cell and relatively greater permeability of K+ than Na+ ions into the cell allowing for passive transport out the cell.
negative proteins
ATP in transport required because_____, this is an example of ____. Each time the pump is used, it results in the inside of the cell becoming more _____
Na+ and K+ are moved against their gradients,
primary active transport
more negative
Depolarization
excitatory inputs to neuron raising the membrane potential, making it more likely to release an action potential
Hyperpolarization
inhibitory inputs to the neuron lowering the membrane potential to make neurons less likely to fire action potential
Summation
additive effect of multiple excitatory and inhibitory signals