What describes the ability of heart to function as a single unit​

in other conditions, the heart can be considered accurately as a single unit in which cardiac output is related to right atrial pressure. ... At the normal right atrial pressure (0 mm Hg), cardiac output will be at its normal value, approximately 5 L/min for a normal size healthy human.

i'm pretty sure questions like these aren't allowd.   but, sure.   i can and talk : ))

it gonna be c hope it