This
is about the size of your heart. One
hundred times every minute your heart muscles squeeze together and push
blood around your body through tubes
called blood vessels. There
are three main kinds of blood vessels, the arteries,
the capillaries, and the veins.
These blood vessels differ in blood flow direction and size.
The heart is like a miniature pump, pumping blood through more than 60,000
miles of blood vessels. Thatís enough to circle the equator twice and then
some!
On an average life span, the heart beats
three billion times without a break. Try squeezing a rubber ball with your
hand every second, your hand soon gets tired, but your heart beats more
than thirty million times every year. That is over 2,000,000,000 (two thousand
million) times a lifetime. The heart works hard while we sleep or relax
and even harder when we work or exercise. It never stops for rest
or repair.
Your heart, blood vessels,
and blood work together to supply each of your cells
with all its needs. Every minute, the heart pushes a pulsing stream of
blood to every cell in your body. So this is why the heart can live even
after the brain dies (brain death). But if the heart dies and the brain
lives, the patient passes out since the blood isn't supplying oxygen to
the brain. With about 15 minutes the patient is dead. Before then,
doctors work to bring the heart back, or revive it. Electric
shocks reset the heart timer to work properly.
Your heart is in the middle
of your chest, tilted slightly to the left. It weighs only about ten ounces,
about as much as one of your sneakers. The
heart is made mainly of muscle, and has four main chambers.
Plain, old facts!
*An average adult has five liters of blood.
* The blood makes up 1/3 of the bodyís weight.
*The heart beats, on average, seventy times a minute.
*Heart attacks are a major cause of death in the Western countries.
*In the United Kingdom, about one baby in 125 has a heart disorder.
