Where do the arrows in a food chain or food web represent

Arrows on a food chain, or food web, represent the flow of energy.

Explanation:

"The placement of the arrows in a food chain or food web is very important. The arrows always show the direction of the energy as it is transferred from one organism to another."

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.