The heart is a hollowmuscle that pumps blood throughout the blood vessels by repeated, rhythmic contractions. It is found in all animals with a circulatory system (including all vertebrates).
The average human heart,
beating at 72 beats per minute, will beat approximately 2.5 billion
times during an average 66 year lifespan. It weighs approximately 250 to
300 grams (9 to 11 oz) in females and 300 to 350 grams (11 to 12 oz) in
males.
Different ways to hold a heart, steal it, snatch it, grip it, care for it...
project I, september 2012.