Essential Key Terms to
Know
A summary of all the most important terms you need to know
Nerve Cells and Nerve Impulses
Terms:
Afferent: bring info in
Efferent: brings info out
Neuron Shapes
Different neuron shapes allow us to determine different things
Ex: bee has dense neurons allowing her to absorb various information from different senses
Different neurons have different locations
Ex: pyramidal cells – motor cortex to spinal cord to send motoric output
Bipolar cells – retina (process visual info)
Purkinje - cerebellum
, Bio & Neuropsychology
Glial cells:
Smaller + numerous than neurons
Neurons: receive and pass info
Glial: different function (hygiene, nutrition)
Astrocytes: provide physical and nutritional support, clean up dead neurons “debris”,
coordinate activity (shortly inhibiting + synchronizing), guide formation and elimination of
synapses
Microglia: Part of immune system – digest waste material + toxins
Oligodendrocytes: build myelin sheath in CENTRAL NS (brain and spinal cord), + nutrients
Schwann cells: build myelin sheaths in PERIPHERAL NS around certain vertebrate axons +
nutrients
Radial glia: guide migration of neurons, axons, dendrites during embryonic development
Differences from neurons:
Glial cells only have ONE axon
Glial cells cannot generate action potentials (do have resting potentials)
Glial cells DON’T have chemical synapses
Blood-brain barrier: protects brain from large charged molecules. Small,
uncharged, soluble in fat molecules can enter.
Wall of endothelial cells
Resting Potential:
Polarization: electrical gradient: difference between inside and outside of cell
Resting potential: difference in electrical charge in a resting neuron. Resting potential has
negative charge
Sodium-potassium pump: pumps potassium (K) into the cell and sodium (Na) out of cell
Concentration gradient: sodium wants to enter cell
Sodium: two forces want to work sodium into neuron, Potassium: one force wants
potassium into cell and one wants it out
Action Potential: