Graded Potentials and Action Potentials

A comprehensive set of flashcards covering the key concepts related to graded potentials, action potentials, their properties, and relevance in neural signaling.

Graded Potentials

Small changes in membrane potential that can vary in magnitude and are used for short-distance signaling.

Action Potentials

Large, all-or-nothing electrical signals that travel long distances down axons.

EPSP

Excitatory Postsynaptic Potential; a graded potential that depolarizes the postsynaptic cell, making it more likely to fire an action potential.

IPSP

Inhibitory Postsynaptic Potential; a graded potential that hyperpolarizes the postsynaptic cell, making it less likely to fire an action potential.

Resting Membrane Potential

The baseline electrical charge of a neuron, typically around -70 millivolts, maintained by selective permeability to ions.

Equilibrium Potential

The membrane potential at which there is no net movement of a particular ion across the membrane.

Threshold Potential

The level of depolarization required to trigger an action potential, approximately -55 millivolts.

Generator Potential

A type of graded potential that occurs in sensory receptors in response to stimuli.

Postsynaptic Potential

Graded potentials that occur in the postsynaptic cell resulting from neurotransmitter binding.

End Plate Potential

A large graded potential that occurs at the neuromuscular junction, leading to muscle contraction.

Decremental

A property of graded potentials where their amplitude decreases as they spread along the membrane.

Summation

The process by which multiple graded potentials combine to produce a larger change in membrane potential.

Sodium Channels

Ion channels that open to allow sodium ions to enter the cell, contributing to depolarization.

Potassium Channels

Ion channels that can open to allow potassium ions to exit the cell, contributing to hyperpolarization.

Chloride Channels

Ion channels that open to allow chloride ions to enter the cell, leading to hyperpolarization.

Local Potentials

Graded potentials that are localized and diminish over distance, used for short-range signaling.

ionic basis of action potential

tug of war between na+ and k+ channels, resulting in rapid depolarization followed by repolarization of the neuronal membrane.

point of the refractory period

It is mainly considerate to setting up the cell back to normal conditions/resting membrane potential. the cell sets up its own ‘limit’ for the amount of Na+ ions that can enter it, closes the ion channel and lets the remaining Na+ inside gradually leave through Na+/k ATPase. Thus if the neuron has no reason to be active after the first signal, the cell doesn’t have too much work in restoring regular conditions/ a proper balance is there between incoming na+ and ability of Na+/k+ to remove the ions and restore everything in regular conditions just in time before another potential action potential.