Why Are Action Potentials Usually Conducted in One Direction

question 56

Multiple Choice

Why are action potentials usually conducted in one direction?

• A) The nodes of Ranvier conduct potentials in one direction.
• B) The brief refractory period prevents reopening of voltage-gated Na⁺ channels.
• C) The axon hillock has a higher membrane potential than the terminals of the axon.
• D) Ions can flow along the axon in only one direction.
• E) Voltage-gated channels for both Na⁺ and K⁺ open in only one direction.

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Definitions:

Unmyelinated Neurons

Unmyelinated neurons are nerve cells that lack a myelin sheath around their axon, resulting in slower transmission of nerve impulses compared to myelinated neurons.

A-Delta Fibres

Fast-conducting nerve fibers involved in the transmission of pain and temperature sensations.

Supertaster

An individual with a heightened sensitivity to the tastes of foods, especially bitter and sweet, due to a higher density of taste buds.

Sweet and Bitter Tastes

Basic taste sensations that enable organisms to evaluate the nutritional value of foods, with sweet generally indicating energy-rich sources and bitter indicating potentially harmful substances.