The Journey of the Sperm: A Race to the Egg

A single teaspoon of semen can contain over 200 million sperm.
Most sperm never make it past the cervix — only a few thousand reach the egg.
Each sperm swims using its tail, powered by mitochondria.
The female reproductive tract helps guide the strongest sperm forward.
Sperm must survive acidic environments and immune defenses along the way.
The journey to the egg can take minutes — or several hours.
Only the healthiest sperm can penetrate the egg’s protective layer.
Once one succeeds, all others are locked out instantly.
The winning sperm determines the baby’s sex — X for female, Y for male.
Every conception is the result of one incredible microscopic race.