Chill Out, Penis

“A penis in repose, although it seems floppy and relaxed, is actually in a state of constant, moderate contraction. The tube of smooth muscle that runs down its center is mildly tensed. So are the linings of the thousands of tiny blood vessels that crisscross the organ. Further contraction of this muscle and the arteries is what accounts for shrinkage in cold weather or water. So although a penis in the process of erecting can seem like it’s springing into action, it’s actually submitting to a crucial, and opposite, process. First it must relax.”
 — There’s a whole bunch about penises going on right here. A veritable peniscopia, if you will.