THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Coronary veins are responsible for draining deoxygenated blood from the myocardium into the cardiac chambers. Comprised of two venous systems, coronary veins classify into either the greater cardiac venous system or the smaller cardiac venous system.

Detailed explanation-2: -The greater cardiac veins account for 95% of all venous drainage from the heart. The smaller cardiac veins also known as the thebesian veins are luminal vessels and drain directly into the respective cardiac chambers.

Detailed explanation-3: -Oxygen-poor blood returns from the body to the heart through the superior vena cava (SVC) and inferior vena cava (IVC), the two main veins that bring blood back to the heart. The oxygen-poor blood enters the right atrium (RA), or the right upper chamber of the heart.