More than 340 years ago, a Dutchman invented the new compound microscope and accidentally discovered the existence of bacteria. This proved to be a groundbreaking achievement that changed the course of medicine. It wasn’t long before he decided to look at his ejaculate via his compound microscope. He discovered tiny little animals with tails. According to his observation, these creatures moved forward owing to the motion of their tails.
The Dutchman wrote to the secretary of the U.K Royal Society in 1678. In his letter, he wrote that the tail of a man’s sperm is similar to the movement of a snake or an eel. For more than three centuries now, Science has held that sperms swim like wiggling eels. Their tails gyrate to and fro as these sperms look for an egg to fertilize. This is precisely how it appears under a microscope.
We Thought We Knew How Sperm Swam, But It Was Just an Optical Illusion!
Under a 2D microscope, it was clear that their tails propelled the sperms. These tails seemed to wiggle side to side as the sperm’s head rotated. However, after carrying around this theory for almost three centuries, we know it was just an optical illusion.
With a new 3D microscope and high-speed video, it was revealed that sperms don’t swim in this symmetrical motion at all. In technical terms, how the sperms move is called precession, meaning it rotates around an axis. The sperms swim in a narrow channel of very sticky fluid in the cervix, walls of undulating cells in the fallopian tubes. Simultaneously, these sperms have to battle heavy muscular contractions and fluid being pushed along in the opposite direction where they want to go.