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Sensory system

From CreationWiki, the encyclopedia of creation science

Sensory systems are biological systems designed to detect signals from the environment, such as sound waves, odors, and tastes. Sensory organs like eyes, ears, nose, and the tongue have specialized cells equipped for sensing specific types of stimulus. For example, you can hear the phone ring because sound waves vibrate hairlike projections (called stereocilia) that extend from cells in your inner ear. The message is then communicated through the nervous system. Similarly, for you to see and smell the world around you and taste its variety of flavors, your body must convey molecular signals from the environment into your sensory cells.^[1]

Researchers have discovered that what's sending that signal is a channel protein jutting through a cell membrane, through which charged particles (primarily potassium ions) pass, triggering the release of neurotransmitters. Highly specialized molecules called G proteins are key players in this transmission process. When odor molecules hit the inside of your nose, they are received by receptor molecules on the surfaces of nerve cells. The odor message fits into a specially shaped site on the receptors, nudging the receptors to interact with G proteins on the inner surface of the nerve cell membrane. The G proteins then change their own shape and split in two, which sets off a cascade of chemical reactions inside the cell. This results in an electrical message that travels from your nose to your brain, and evokes your response.^[1]