Action Potentials Flashcards
Oligodendrocytes
CNS
Produce myelin around axons
Schwann cells
PNS
Produce myelin around axons
Ganglia
PNS
Neuron cell bodies of the same type clustered together
Nuclei
CNS
Neuron cell bodies of the same type clustered together
Glial cells
Structural and supportive roles
Include: Astrocytes, Ependymal cells, Microglia, Oligodendrocytes, and Schwann cells
Astrocytes
Nourish neurons
Form blood-brain barrier
Ependymal cells
Produce cerebrospinal fluid, which physically supports the brain and serves as a shock absorber
Microglia
Phagocytic cells that ingest and break down waste products and pathogens in CNS
depolarization
Excitatory input causes depolarization, raising the membrane potential (more +)
hyperpolarization
Inhibitory input causes hyperpolarization, lowering the membrane potential (more -)
temporal summation
multiple signals are integrated during a relatively short period of time
spatial summation
the additive effects are based on the # an location of the incoming signals.
absolute refractory period
no amount of stimulation can cause another action potential to occur
relative refractory period
there must be a greater than normal stimulation to cause an action potential because neuron is hyperpolarized
