Because your body is gearing up for digestion, the process that converts food into energy (and into some yucky stuff, too, but we’ll get to that in a bit). Glands in your mouth secrete a watery substance called saliva (aka spit), which contains chemicals that help melt chewed food into slimy gobs of mush – each called a bolus – for easier swallowing. Your tongue herds every bolus to the back of your throat and drops it into your esophagus, a pipe that squeezes everything you eat into your stomach.
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