Everyone is tweeting the TED penis talk
Diane Kelly: What we didn’t know about penis anatomy
Fun talk. She proves that anatomy still has much to teach. She also has a blog
In the TED talk, she discusses hydrostatic skeletons. These consist of fluid-filled cavities supported by a helical weave of collagen. In most animals with such skeletons, the helical weave is at a 45 degree angle to the axis of the shaft. This allows compression and flexation. Great if you are a worm, not helpful if you are a penis on a mission. She discovered, during her Ph.D., that the penis aligns the helical weave along the axis. This gives the needed rigidity to the structure.