Species range in size from the hefty Common Raven (Corvus corax), at 1.5 kg (3 lb 5 oz) and 70 cm (2 ft 3 in), to the diminutive Short-tailed Pygmy Tyrant (Myiornis ecaudatus), at just 4.2 g (0.14 oz) and 6.5 cm (2 Â½ in).
The heart receives its own supply of blood from the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet. These arteries and their branches supply all parts of the heart muscle with blood.hen the coronary arteries narrow to the point that blood flow to the heart muscle is limited (coronary artery disease), collateral vessels may enlarge and become active.
Unlike the rest of the body, the liver is the only organ in the body that gets most of its oxygen supply from a vein. The liver receives the oxygen and nutrients it needs in blood that comes from two large blood vessels: Portal vein.Hepatic artery. The portal vein provides about two thirds of the blood.he hepatic veins carry blood to the inferior vena cavaâthe largest vein in the bodyâwhich then carries blood from the abdomen and lower parts of the body to the right side of the heart. Blood vessel (vascular) disorders of the liver usually result from inadequate blood flowâwhether into or out of the liver.