And we have a pump on the left side that consists of the left atrium and the left ventricle. Now, unlike skeletal muscle which is actually attached to our bone and contracts with the bone, the heart is not actually attached to any bone. The heart consists of cardiac muscle which forms a web like net that contracts upon itself. Now, what exactly is the function of our heart? Well, the heart essentially creates that hydrostatic pressure that is needed to move the blood through the blood vessels of our body. Now, what exactly is a blood vessel?