The Nose Knows
You've been outside playing after school. But now your mom has called you to come in and wash up for supper. You step in the back door just as your mom pulls out of the oven a pan of her homemade lasagna. The smell drifts through the whole house: bubbly cheese, soft noodles, tender meat, and just the right spices. From the griddle she lifts off hot, freshly buttered french bread. Your mouth begins to water, and your stomach begins to “growl.” What's happening here?
Your nose knows! Your nose is sending messages to your brain; messages which tell the brain to check in its vast “filing cabinet” of memories for what these odors mean. Ah ha! It's lasagna. It's cheese. It's butter. What a wonderful thing, the nose. Can you imagine going through life without the sense of smell which the nose provides?
But how does the nose work? It is not actually our nostrils which do the smelling. Nostrils collect the odors, but the epithelium (ep-uh-THEE-lee-um) located behind the bridge of the nose is what captures odor molecules. Then, in a series of very complex steps, tiny nerves send electrical impulses to the part of the brain we call the smell cortex. The brain uses its huge memory to match the odor to something the nose has smelled before, and recorded in the brain. When you smell lasagna, the brain sends a message of “good.” But when you smell something like rotten eggs, the brain sends a message of “bad.”
The nose is also one part of the body's defense system. Bacteria in the air are “captured” by the mucus (fluid) in the nose and dissolved. Some objects in the air, like pollen from plants, may irritate the trigeminal (try-JEM-i-nul) nerves, causing a sneeze to occur. During a sneeze, foreign objects can be propelled from the nose at a speed of over 100 miles per hour. Interestingly, nostrils “switch on and off” every 3-4 hours. One will work while the other rests.
Could the nose have “just happened” by evolution? No! It is so well-designed, and so complex, that it must have had a designer. That designer is God, Who made us (Genesis 1:26,27; Psalm 139:14).