GENERAL HISTOLOGY

Detailed explanation-1: -The superior vena cava is the large vein that brings blood from the head and arms to the heart, and the inferior vena cava brings blood from the abdomen and legs into the heart.

Detailed explanation-2: -Arteries carry blood away from your heart. Veins carry blood back toward your heart. Capillaries, the smallest blood vessels, connect arteries and veins.

Detailed explanation-3: -While arteries carry oxygen-rich blood, veins carry oxygen-poor blood. Your pulmonary veins are an exception to this rule. These four veins, located between your heart and lungs, carry oxygen-rich blood from your lungs back to your heart. From there, your heart pumps the oxygen-rich blood back throughout your body.