penis
"During an erection, the blood enters the penis faster and the veins pinch off (occlude) causing the tunica albuginea to expand. In a way, the penis is like a sink with a faucet and drain. The faucet is always on (not full force) and the drain is open. An erection is in a way like turning up the flow from the faucet and plugging the drain.In simple terms, an erection happens because the brain tells nerves to release a substance in the penis."
"Your penis is like a prince in a fairy tale. But my vagina is a Ken Burns mini-series."
"But for men, the penis is like a trophy they can't seem to put down. It's a comfortable old friend they don't want to stop hugging. It's due north on a compass that helps them find direction. It's something to hold simply because it's there."
"The corpora are much like a bicycle inner tube. The skin of the penis is like the tire over the tube."

METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.