My heart and lungs

As I breath, my body trembles

Gases exchange across tiny membranes

Oxygen fills my lungs with sweet inspiration

Carbon dioxide is expelled with every expiration

Transferred to and from pulmonary arteries and veins

By blood gated by a semilunar valve

Left atrium to ventricle, aorta to the rest of the body

To the smallest capillary

Energy circulates, and navigates

Somehow to all vascularized cells and tissue

In each issue of blood

Waxing and waning like a great tide

To the beating sound of life

My heart pumps 

My blood flows

Existence pounds against my chest