Central Nervous System Flashcards
What is the function of the axon hillock?
the final site where membrane potentials propagated from synaptic inputs are summated before being transmitted to the axon
What is the function of dendrites?
usually covered with many synapses, dendrites are the principal signal reception and processing sites on neurons
What is arborization?
think of tree branches; arborization allows a single neuron to receive and integrate signals from many other nerve cells
What is the function of axons?
conduct action potentials from cell body to synaptic terminal; allows rapid communication
What occurs in terminals (Boutons)?
Action potential travels down the nerve, facilitates release of synaptic vessicles which release acetylcholine to the postsynaptic neuron; can be taken back up to transporters
What are autoreceptors?
presynaptic (associated with terminals); when activated by transmitter, they will slow down the neuron
What are the 4 types of CNS glial cells?
astrocyte
ependymal cell
microglial cell
oligodendrocyte
What is the function of astrocytes?
Helps form blood-brain barrier
Regulations IF composition
Structural support & organization of CNS
Neuronal development
Replicates to occupy space of dying neurons
What is the function of ependymal cells?
Lines ventricles of brain and central canal of spinal cord
Assists in production and circulation of CSF
What is the function of microglial cells?
Phagocytic cells that move through the CNS
Protects the CNS by engulfing infectious agents and other harmful substances
What is the function of oligodendrocytes?
Myelinates and insulates CNS axons
Allows faster AP propagation along CNS axons
Gray matter vs. white matter
Gray matter is rich in neuronal perikarya and astrocytes
White matter is found in regions containing tracts of myelinated axons
What is the neurotransmitter for the sympathetic nervous system?
norepinephrine
What is the neurotransmitter for the parasympathetic nervous system?
acetylcholine
