Historical biological theories tend to describe that behaviors are inherited biological tendencies passed down through evolution, and contemporary biosocial theories are explained by saying that genes and other biological features are more facilitators of human behavior instead of determinants.
Like the heart, the LVAD is a pump. One end hooks up to the left ventricle -- that's the chamber of the heart that pumps blood out of the lungs and into the body. The other end hooks up to the aorta, the body's main artery. A tube passes from the device through the skin.
The heart pumps blood in a two-step process. The atria pump blood into the ventricles and then the ventricles pump blood out of the heart. Chambers of the heart fill with blood during a relaxation phase (diastole) and eject blood during a contraction phase (systole). Atrial systole precedes ventricular systole.