FLASH CARDS www.biologicalpsych.com Kalat s Book Chapter 2 Alphabetical
absolute refractory period
absolute refractory period Time when neuron will not re-fire no matter how much stimulus it gets.
action potential
action potential Nerve impulse. Changes in electric potential actively open and close ion gates as the impulse moves down the axon.
active transport
active transport As opposed to passive transport. Active transport requires the use of energy, usually glucose. Moves ions from low to high concentrations.
afferent axon
afferent axon Sensory neuron sends information toward the spinal cord and brain.
all-or-none law
all-or-none law A neuron can fire or not fire; no partial firing allowed, no partial strength.
astrocyte
astrocyte A type of glial cell. Holds neurons in place, reuptakes some neurotransmitters.
axon
axon Long thin extension carries the nerve impulse away from the soma. The output part of the neuron.
axon hillock
axon hillock In large neurons, the place where the soma and axon connect. Lots of voltage-gated ion channels here.
blood-brain barrier
blood-brain barrier Blood capillaries with very tight walls to keep disease out of the brain.
concentration gradient
concentration gradient The tendency for things (including ions) to move from high to low levels of concentration. Requires no energy to occur.
dendrite
dendrite Thick stubby extension of neuron. Has neurotransmitter-gated ion channels. The input part of a neuron.
dendritic spine
dendritic spine Receives input from single synapse. Three types: stubby, thin & mushroom.
depolarization
depolarization Moving to opposite pole. In a neuron s case, moving from a negative voltage toward a positive voltage.
efferent axon
efferent axon Motor neuron sends information away from the spinal cord and brain.
electrical gradient
electrical gradient The difference between the voltages inside and outside the cell.
endoplasmic reticulum
endoplasmic reticulum An cell organelle that forms tubes and storage places for proteins, neurotransmitters, etc.
glia
glia Also called neuroglia or glial cells. Probably not much more common than neurons, despite 10:1 ratio statements. Have resting potential, no neurotransmitter, no dendrites. Neural glue = holds neurons in place.
glucose
glucose D-glucose or dextrose. Absorbed directly into blood stream without processing. Primary source of cell energy.
graded potentials
graded potentials A gradual or incremental change in electrical potential caused by neurotransmitters activating protein ion channels. Transduction process in neurons and sensory receptors.
hyperpolarization
hyperpolarization Going further the direction already headed. If negative, going more negative. In a neuron, the result of potassium channels shutting slowly.
interneuron
interneuron Also called association, relay or intrinsic neuron. Connects neurons to other neurons. Inside CNS (central nervous system).
intrinsic neuron
intrinsic neuron An interneuron.
local anesthetic
local anesthetic Drugs that causes temporary loss of sustentation in a specific area of the body by blocking the opening of sodium channels.
local neuron
local neuron An interneuron.
membrane
membrane Thin layer of lipids that forms a boundary; often refers to a cell membrane.
microglia
microglia Type of glial cell (account for about 20%). Prune neurons, activate T-cells, and remove plague and damaged cells.
mitochondrion
mitochondrion Plural term is mitochondria. Cell organelles that generate ATP.
motor neuron
motor neuron Neurons in CNS (central nervous system) that project axons to peripheral nervous system. Activate muscles, directly or indirectly. Also called efferent neurons.
myelin
myelin A layer of protein and lipids that insulates axons. In PNS, a series of Schwann cells wrap around axons. In CNS, oligodendrocyte cells insulate many axons that pass through them.
myelin sheath
myelin sheath A coating of myelin on a PNS axon.
myelinated axons
myelinated axons Axons with myelin sheaths of Schwann cells.
neurons
neurons A cell that releases a neurotransmitter (NT) as a result of being stimulated by a NT. Able to depolarize and repolarize.
nodes of Ranvier
nodes of Ranvier Gaps between Schwann cells.
nucleus
nucleus Part of cell that contains DNA. Controls cells growth and reproduction.
oligodendrocyte
oligodendrocyte Glial cell that myelinates cells in the brain.
passive transport
passive transport As opposed to active transport. Does not require energy. Water and oxygen move across a cell membrane freely. Includes diffusion and osmosis.
polarization
polarization Headed to a pole. If positive, becoming more positive; if negative, becoming more negative.
presynaptic terminal
presynaptic terminal End of an axon that releases neurotransmitter; causes a change in a postsynaptic neuron.
propagation of action potential
propagation of action potential Movement of neural impulse down axon, caused by the successive opening of voltagegated ion channels.
radial glia
radial glia Type of glial cell. Forms tree that founder cells climb to create the brain.
refractory period
refractory period Time needed for a neuron to fully recover. Typically 3-5 ms, not counting hyperpolarization (which can add10-15 ms, depending on the neuron).
relative refractory period
relative refractory period Time needed for a neuron to recover to the point where a giant stimulus will make the neuron fire.
resting potential
resting potential Voltage of a neuron at rest. Typically about minus 70 mv.
ribosomes
ribosomes Complex molecular system for synthesizing proteins. Uses RNA to sequence amino acids.
saltatory conduction
saltatory conduction Can be 10x faster than cable conduction. Impulse jumps from node to node of myelinated axon.
Schwann cells
Schwann cells Wrap around an axon in PNS and cover it with myelin.
selective permeability
selective permeability Membrane that allows some things to easily pass through, other thing pass through only if gates are open.
sensory neuron
sensory neuron Also called an afferent neuron. Takes information from senses toward brain.
sodium-potassium pump
sodium-potassium pump An active process (requires energy). Maintains proper level of ions. Pumps out 2 sodium ions for every potassium ion that enters cell.
soma
soma Cell body; contains the nucleus.
thiamine (vitamin B1)
thiamine (vitamin B1) Water soluble vitamin, used to make GABA. Beriberi is caused by lack of thiamine.
threshold
threshold Cutoff level beyond which something different happens. In neurons, crossing a voltage threshold opens voltage-gated ion channels, causing it to fire.
voltage-activated channels
voltage-activated channels Open when voltage in cell reaches a threshold. In neurons, voltage-gated or activated channels open at about -55 mv.
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