PATHOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -The right and left brachiocephalic veins, also known as the innominate veins, join to form the superior vena cava posterior to the inferior border of the first right costal cartilage. These veins carry blood from the chest wall, esophagus, lungs, neck, and pericardium.