The Human Heart

The human heart is the organ most needed for life.The heart is defined/recoginized
as a muscular,pear-shaped organ slightly larger than a clenched fist, which is located
in the center of the circulatory system.The heart has the hardest job which is pumping
blood throughout the whole human body.It pumps blood at a rate of more than 4
quarts a minute and weigh around 8-12 ounces, this organ beats at a rate of 72 times
a minute (on an average).The heart is one of the most amazing organs!
The heart is a very strong muscle. It consists of several layers of tough
muscular wall, called the myocardium. The outside is covered by a thin tissue called
the pericardium and the inside is linded with a layer called the endocardium. The
heart is divided in the middle to make the right and the left heart, which in turn are
subdivided into 2 chambers. The auricle, is the upper chamber and the ventricl is the
lower chamber.The auricles recieve blood for entering the heart; the ventricles ...