Why dont we also include the spatial coordinate zwhen drawing the light cone

Path blood takes L atrium--> Bicuspid valve--> L ventricle--> Aortic semilunar valve--> Aorta--> Arteries--> Arterioles--> Capillaries--> Venules--> Veins--> Vena cava--> R atrium--> Tricuspid valve--> R ventricle--> Pulmonary semilunar valve--> L and R Pulmonary arteries--> Lung Best explanation of the function of heart valves Prevent backflow Cardiac cycle: Late diastole Both sets of chambers are relaxed Ventricles fill passively Atrial systole Atrial contraction forces a small amount of additional blood--> ventricles Isovolumic ventricular contraction 1st phase of ventricular contraction Pushes AV valves closed Not enough pressure to open semilunar valves Ventricular ejection As ventricular pressure rises and exceeds pressure in the arteries Semilunar valves open Blood is ejected Isovolumic ventricular relaxation As ventricles relax Pressure in ventricles fall Blood flows back into cusps of semilunar valves and snaps them closed Systole: Contraction and emptying Diastole: Relaxation and filling P-wave: Atrial depolarization, before contraction QRS complex: Ventricular systole @ beginning, atrial repolarization End diastolic volume @ end of diastole, after QRS T-wave: Ventricular repolarization Blood--> ventricles Passively through atria: 80% Through atrial systole: 20% Ventricular Systole 2 phases Isovolumic contraction AV valves closed Semilunar valves closed Ejection AV valves closed Semilunar valves open Stroke volume: Amount of blood ejected from one ventricle in one cardiac cycle During a single systole End diastolic volume - end systolic volume Expres