Neurons and Electrical Signals

A series of vocabulary flashcards covering key terms related to neuron function and electrical signaling.

Ion Movement

The process by which ions move across a membrane, influencing electrical activity in neurons.

Diffusion

Movement of ions from an area of high concentration to an area of low concentration.

Concentration Gradient

Differences in concentration of a substance among regions that allow for diffusion.

Voltage Gradient

Difference in charge between two regions that allows for ion flow.

Resting Membrane Potential

The charge across the cell membrane in the absence of stimulation, approximately -70mV.

Sodium (Na+)

An ion with a higher concentration outside the cell at rest; contributes to the action potential.

Potassium (K+)

An ion with a higher concentration inside the cell at rest; crucial for maintaining resting potential.

Action Potential

A brief and large reversal of charge in an axon initiated at the axon hillock when enough EPSPs are received.

Threshold Potential

The membrane voltage at which an action potential is triggered, approximately -50mV.

Absolute Refractory Period

The time when a new action potential cannot be initiated regardless of the stimuli due to sodium channels being closed.

Relative Refractory Period

The period during which a new action potential can be triggered but requires a stronger stimulus.

Saltatory Conduction

The process of action potentials jumping from node to node along a myelinated axon, increasing conduction speed.

Node of Ranvier

A gap in the myelin sheath of an axon that contains voltage-sensitive channels, facilitating rapid conduction.

Electrolytes

Ions in biological fluids that carry electrical charge and are essential for nerve signal transmission.

Graded Potentials

Brief, small voltage fluctuations across the membrane in response to stimulation.