Sperm cells are incredibly small, measuring just 0.005cm in length. This makes them some of the smallest cells in the human body. To put that into perspective, a human sperm cell is about 6000th of a centimeter long, a tiny fraction of a man's total body length.
The head of a sperm cell is flat and disc-shaped, measuring 5.1 μm by 3.1 μm, while its tail, known as a flagellum, is 50 μm long. The flagellum propels the sperm cell by whipping in an elliptical cone, allowing it to travel at a speed of 1–3 mm/minute in humans.
While sperm cells are tiny, they are highly specialized cells designed for the task of fertilizing an egg. They contain a unique set of proteins called protamines, which help condense and protect the DNA within the sperm head. This ensures the genetic material is delivered safely to the egg for fertilization.