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Glossary of Physiology Terms
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There are 7 glossary search results for:   current




Definition:
An electrophysiological technique in which the current passing across the cell membrane is controlled experimentally, and the membrane voltage is measured.

Related glossary terms/phrases:
Voltage clamp

See also:
Neuronal Action Potential - Pharmacological Inhibition of Na+ and K+ Channels



Definition:
The flow of charge. In electrical wires and electronic circuits, current is carried by electrons. In physiological solutions, current is carried by ions in solutions.

Related glossary terms/phrases:
Voltage



Definition:
In electrophysiological convention, a negative current value or downward deflection of a current trace is typically referred to as an inward current. A negative current value (i.e., inward current) can reflect either the movement of positive ions (cations) into the cell or negative ions (anions) out of the cell.

See also:
Neuronal Action Potential - Pharmacological Inhibition of Na+ and K+ Channels



Definition:
In electrophysiological convention, a positive current value or upward deflection of the current trace is typically referred to as an outward current. A positive current value (i.e., outward current) can reflect either the movement of positive ions (cations) out of the cell or negative ions (anions) into the cell.

Related glossary terms/phrases:
Inward current

See also:
Neuronal Action Potential - Pharmacological Inhibition of Na+ and K+ Channels



Definition:
Electrophysiology is the study of the electrical properties of biological macromolecules, cells, tissues, and organs. Electrical signals such as voltage and/or current are generally measured. Examples include measuring changes in the membrane voltage of excitable cells (e.g., neurons, muscle cells, and some endocrine cells) during an action potential. The current carrried by ions as they permeate the pore of ion channels can also be measured - both at the single-channel level (single-channel current), as well as the macroscopic current resulting from the activity of a population of channels. As another example, electrical measurements may involve recording voltage changes at the surface of the skin that result from the activity of skeletal muscles (electromyogram, EMG), cardiac myocytes (electrocardiogram, ECG), or neurons in the brain (electroencephalogram, EEG).



Definition:
A rectangular signal waveform used in physiological studies to perturb (i.e., challenge) the system under study. The response of the system to the pulse is then studied carefully to learn about how the system responds to challenges.

Examples include pulses of voltage or current in electrophysiological experiments. Other examples include pulses of light, pressure, temperature, ligand, etc.

A square-wave pulse is defined by the amplitude and duration of the pulse, as well as by the frequency at which the pulse is applied to the system under study.

See also:
Neuronal Action Potential - Introduction

Other resources:
Square wave (Wikipedia)



Definition:
An electrophysiological technique in which the voltage of a cell membrane is controlled experimentally, and the current passing across the membrane is measured.

Related glossary terms/phrases:
Current clamp

See also:
Neuronal Action Potential - Pharmacological Inhibition of Na+ and K+ Channels









Posted: Sunday, March 31, 2013
Last updated: Friday, August 28, 2015