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Thumbs

Thumbs

14 The thumb, unlike other fingers, is opposable, in that it is the only digit on the human hand which is able to oppose or turn back against the other four fingers, and thus enables […]

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Skin

Skin — Integumentary System

19 ‘Your skin is amazing, Vaseline commercial: waterproof barrier, defense against disease, adjusts to surroundings, constantly growing and replacing itself, heals itself, all 800 million cells — do you see skin the way we do? […]