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.
Arteries. All blood vessels leading from the heart are called arteries or the blood vessels which carry blood from the heart to various body organs are called arteries. All arteries carry oxygenated blood (pure blood) except pulmonary artery, which carries deoxygenated blood.n closed circulatory system blood is circulated through closed vessels such as arteries, veins and capillaries. 1. Vessels which carry blood from the heart to various body parts. 2. Arteries carry oxygenated blood from the heart except pulmonary artery.