A toddler could swim through a whale's arteries

The heartbeat of a blue whale can be detected by sonar from over two miles away. This massive pump weighs 400 pounds and moves 60 gallons of blood with every single contraction.

The aorta, the main artery leaving the heart, is over nine inches wide. This makes it large enough for a small child to swim through, though the pressure would be lethal.

Gravity is the whale's biggest enemy. On land, a heart this size would collapse under its own weight, but the buoyancy of the ocean acts like a support suit. This allows the heart to beat as slowly as twice per minute when the whale dives deep.

Despite having veins the size of plumbing pipes, the whale’s throat is surprisingly narrow. Large enough to house a heart the size of a golf cart, the animal can only swallow prey the size of a grapefruit.

Even more bizarre, the blue whale has the largest tongue on the planet, which alone weighs as much as an entire African elephant.