heart anatomy diagram. human heart structure. labelled heart half in doodle style. education. hand drew .

heart anatomy structure system aorta aortic artery atrium attack biology blood body cardiac cardiology cardiovascular cava chamber circulation coronary cross section diagram doodle drawing education hand draw health heartbeat human illustration internal left ventricle medical medicine model muscle myocardium organ pulmonary pulse pump right scientific teach valve vector vein labelled half style part foe drew