Ira Sanders, Liancai Mu

ScienceShot: Your Tongue, Inside Out

We use our tongues whenever we speak or swallow, but much about how they work remains a mystery. Now, researchers have constructed a 3D computer model of the human tongue that could help reveal its secrets. The model is based on data from the Visible Human Project, which froze a dead man and woman in blocks of gelatin in the 1990s and cut them into many thin slices to scan them. The scientists improved their model by analyzing slices of three additional human tongues, whose translucency helped reveal the complex interweaving of muscles throughout the organ. Unlike arms and legs that rely on bones to behave in a familiar way, like classical levers, tongues operate bonelessly like the tentacles of an octopus, with the motion of any lone muscle depending on the activity of surrounding muscles in a complex manner that researchers do not yet fully grasp. The new model, reported online this week in The Anatomical Record, now shows where each muscle (various colors in picture above) is positioned in relation to each other and the jaw (gray), and it could yield insights on how they work together. A number of tongue muscles overlap so extensively, for example, that they might best be treated as a single entity.

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