Brooms for Your Breath

What am I looking at?

These are cells that line the trachea of a mouse. The blue-gray, rounded cells (1) produce mucus that lines the trachea and helps protect it. The multicolored, hairy-looking cells (2) are specialized cells that clean the mucus. These cells were false-colored so they stand out and their structure is more visible.

Biology in the background

The trachea, also known as the windpipe, is the connection between the larynx and the lungs. It is also the first line of defense against bacteria, viruses, allergens, pollutants, and other debris inhaled from the environment. The cells in this image line the trachea and form the so-called mucociliary escalator. “Muco” indicates that some of these cells produce the mucus that protects the trachea and lungs. And “ciliary” indicates that some of these cells sweep up the mucus, also gathering the contaminants that stick to it, in a manner similar to the way sea anemones gather food from the water. These cells then move any inhaled particles trapped in the mucus up toward the larynx, where they can be coughed out or swallowed.

These mucus-secreting cells are about 18 micrometers across, or roughly four times smaller than the width of a human hair. The ciliated cells have cell bodies about the same size, but the length of a cilium can be up to three times as long, making the total length of the cell roughly the same as the width of a human hair.

Technique  

This image was created using scanning electron microscopy.