Biological Systems MCAT Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the Biological Systems MCAT. Study with detailed questions and explanations. Enhance your understanding and boost your confidence for this crucial exam.

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is the function of the Nodes of Ranvier in a neuron?

To insulate the neuron
To concentrate ion channels
To form synaptic connections
To transmit signals faster

The correct answer is: To concentrate ion channels

The Nodes of Ranvier serve a critical role in the conduction of electrical impulses along myelinated neurons. These nodes are interruptions in the myelin sheath, which is an insulating layer that surrounds the axon of the neuron. One of the primary functions of the Nodes of Ranvier is to concentrate ion channels, particularly voltage-gated sodium channels. When an action potential travels along a myelinated axon, it jumps from one Node of Ranvier to the next in a process called saltatory conduction. This jumping significantly increases the speed of signal transmission compared to unmyelinated fibers, where the action potential must propagate continuously along the entire length of the neuron. Although the presence of myelin is crucial for improving signal speed, the function of the Nodes of Ranvier is specifically tied to the concentration of ion channels that facilitate rapid depolarization and repolarization during the action potential. Thus, while the Nodes of Ranvier contribute to the overall faster transmission of signals and the myelin insulates the neuron, their primary function centers around the concentration of ion channels that enable swift electrical signaling.