Receptorpotenciál

Receptorpotenciál, also known as receptor potential, refers to the change in electrical potential across a sensory receptor's membrane in response to a stimulus. It is a type of graded potential, meaning its size varies with the strength of the stimulus. This electrical response is essential for the transduction process, where physical or chemical stimuli are converted into nerve signals that the brain can interpret.

In sensory cells, receptor potentials occur when specific ion channels in the membrane open or close due to the stimulus. For example, in mechanoreceptors, physical forces like pressure or stretch cause deformation of the receptor, leading to ion channel activation. Similarly, chemical stimuli such as odorants or neurotransmitters can modify receptor conductance in chemoreceptors. The resulting change in membrane voltage can either be depolarizing (making the inside of the cell more positive) or hyperpolarizing (more negative), depending on the stimulus and receptor type.

Receptor potentials do not directly generate nerve impulses; instead, they modulate the activity of sensory neurons. If the receptor potential is sufficient to reach the threshold, it triggers action potentials that propagate along nerve fibers to the central nervous system. The amplitude of the receptor potential is proportional to the stimulus intensity, which allows the nervous system to encode stimulus strength.

Receptor potentials are transient and diminish with continuous stimulation due to adaptation mechanisms. They are fundamental in the sensory process, enabling organisms to detect and respond to environmental changes efficiently. The study of receptor potentials contributes to understanding sensory physiology and the development of sensory aids and prosthetics.

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