Sensory Adaptation

When sensory receptors are continuously stimulated, many of them undergo an adjustment called sensory adaptation. Somehow the receptor membrane becomes less responsive to the stimulus, and the resulting receptor potential generated is less likely to bring the nueron to threshold. As the receptors adapt, impulses leave them at decreasing rates, until finally these receptors may completely fail to send signals. Once receptors adapt, impulses are triggered only if the strength of the stimulus changes.

Imagine a person walking into a fish market. At first, the fishy odor seems intense, but it becomes less and less noticeable as the smell (olfactory) receptors adapt. Soon, the once offensive odor is barely noticeable, but if the person leaves and reenters, he or she again smells the stench.

99 List the five general types of sensory receptors. ^9 What do all types of receptors have in common? ^9 Explain how a sensation occurs. □ What is sensory adaptation?

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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