Which statement concerning graded potentials is true?
A) They are equivalent to the resting potential of the cell membrane.
B) They travel long distances to generate an action potential.
C) They are important in all sensory systems except neuromuscular junctions.
D) They allow a cell to integrate inputs and respond proportionally.
E) They are caused by ionic currents spreading over long distances.

Question

Quizplus · Accepted Answer

Graded potentials allow a cell to integrate inputs and respond proportionally, meaning that the stronger the stimulus, the larger the graded potential will be. This is important for sensory systems, where the strength of a stimulus can vary widely, and the nervous system needs to be able to distinguish between different levels of input. Graded potentials do not travel long distances to generate an action potential (choice B), as they decay rapidly over distance, and they are not equivalent to the resting potential of the cell membrane (choice A), which is a stable potential maintained by ion pumps and channels. Graded potentials are important in all sensory systems, including neuromuscular junctions (choice C), where they can contribute to muscle contraction, but they are not caused by ionic currents spreading over long distances (choice E), as they are local changes in membrane potential caused by the opening or closing of ion channels.

Which Statement Concerning Graded Potentials Is True