Ch. 3

brief fluctuation in membrane pontential caused by the rapid opening and closing of voltage-gated ion channels; also known as spike, nerve impulse, or discharge. travel along axons to transfer info. from one place to another in the nervous system

any membrane capable of of generating action potentials.

the membrane potential, or membrane voltage, maintained by the cell when it's not generating action potentials; aka resting potential (-65 mV)

a property of ion channels that are selectivley permeable to some ions and not to others

a property of many ion channels, making them open or close in response to specific signals, such as membrane voltage or the presence of neurotransmitters

a protein that transports ions across a membrane at the expense of metabolic energy

an atom or molecule that has a net electrical charge bc of a difference in the number of electrons and protons

a positively charged ion

a negatively charged ion

the arranagement of phospholipid molecules that forms the basic structure of the cell membrane. the core of the bilayer is lipid, creating a barrier to water and to water-soluble ions and molecules

the covalent bond between the amino group of one amino acid and the carboxly group of another

a string of amino acids held together by peptide bonds

a membrane-spanning protein that forms a pore that allows the passage of ions from one side of the membrae to the other

the temperatuare -dependent movement of molecules from regions of high concentration to low concentration resulting in more even distribution

a difference in concentration from one region to another. ionic concentration gradients across the neuronal membrane help determine the membrane potential

the rate of movement of electrical charge, symbol (I) measure in amperes; the movement of electrical charge

the force exerted on an electrically charged particle, represented by the symbol V and measured in volts

the force exerted on an electrically charged particle; (v) measure in volts

aka electrical potential or potential difference

the relative ability of an electrical charge to migrate from one point to another; (g) measured in siemens (s). conductance is the inverse of resistance.

the relative inability of an electrical charge to migrate from one point to another; (R) measured in ohms (W)

the relationship between electrical current (I), voltage (V), and conductance (g)

I=gv

the voltage across a cell membrane (V_m)

a probe used to measure the electrical activity of cells.

the electrical potential difference that exactly balances an ionic concentration gradient, (E_ion)

the differenc between the real membrane potential, V_m, and the ionic equilibrium potential, E_ion.

a mathematical relationship used to calculate an ionic equilibrium potential

an ion pump that removes intracellular Na+ and concentrates intracellular K+, using ATP as its energy source

an ion pump that removes cytosolic Ca2+

a mathematical relationship used to predict membrane potential from the concentrations and membrane permeabilities of ions

a change in membrane potential, taking it from the value at rest to a less negative value

a specialization of the walls of brain capillaries that limits the movement of blood borne substances into the extracellular fluid of the brain