<span>They are mechanoreceptors that detect pressure, and are found in the skin and also in joints and tendons. Naked nerve endings lie in the centre of the corpuscle surrounded by concentric layers of connective tissue separated by viscous gel.
Looks like an onion.
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A makes the most sense, though D could actually be an Ok reason, the other two aren't reasonable, a fire safety action? The door would be better open in a fire emergancy, it makes a quicker escape
