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Daniel Ramirez
physiology weeks 7-13
Term | Definition |
---|---|
Neuron membrane potential Resting membrane potential | slightly excess of + ions outside of membrane and less + ions inside of membrane. measurements of volts or milivolts. |
Sodium-potassium pump | Active transport mechanism in plasma membrane Na+ and K+ in opposite direction and at different rates. |
local potentials | slight shift away from resting; specific region of plasma membrane. |
Excitation | stimulus triggers opening of Na+ channels, allowing membrane potential to move to zero (depolarization) |
Inhibition | stimulus triggers opening of K+ channels, increasing membrane potential (hyperpolarization). |
local potentials | graded potential because resting membrane potential is equal to stimulus. |
Neuron action potential | membrane potential conducting impulses (nerve impulse). stimulus triggers Na+ gated channels to open, diffuse in cell (local depolarization). Potential is all or none. membrane potential changes when K+ channels open, diffusion of K+ (repolarization) |
Saltatory conduction | jumps and only occur at the nodes of Ranvier (myelinated) |
Electrical synapses chemical synapses | where cells join by gap allowing action potentials to continue along postsynaptic membrane. where cells release chemical neurotransmitters across gap to postsynaptic cell. |
synaptic knob synaptic cleft | bulge of presynaptic neuron axon containing vesicles of neurotransmitter. space between knob and membrane of postsynaptic neuron |
synaptic transmission | increase Ca+ at knob release neurotransmitters by exocytosis, diffuse across gap/cleft, bind to receptor, causing ion channels to open. |
summation | spatial - adding together of several knobs simultaneously. temporal - knob stimulates in rapid succession. |