Heartbeat Facts

Most mammals, regardless of size, have hearts that beat approximately 1 billion times over their lifetime.

Men have larger hearts; women's hearts beat faster.

Sharks can detect fish heartbeats using electroreceptors called ampullae of Lorenzini that sense electrical fields as small as five billionths of a volt.

A killer whale's heart beats 30 times a minute under water, 60 times a minute on the surface.

During a typical human life span, the human heart will beat approximately 2.5 billion times.

The human testicles produce around 1,000 sperm cells every second — roughly 1,500 with each heartbeat at rest.