Our circulatory system is a closed one. This means that the blood stays in the heart chambers and vessels and does not leave them to circulate in the body cavity. There are three types of vessels: arteries, veins, and capillaries. Arteries carry blood away from the heart, veins carry blood towards the heart and capillaries are the site of nutrient and gas exchange between the blood and the body's cells.
You are responsible for identifying a set of arteries and veins in the cat. Remember this as you begin your dissection: tracing blood vessels is like driving in Tampa. Every time you get to an intersection, the names change. For example, Busch Boulevard crosses 56th Street and becomes Bullard Parkway. The superior vena cava crosses the diaphragm and becomes the inferior vena cava. Or, the right brachiocephalic artery crosses the intersection of the right common carotid and becomes the right subclavian artery. See what I mean?
Vessels are not uniform in type and number. In other words, you may have one brachiocephalic artery (right side), but two brachiolcephalic veins (right and left). Text authors do not label all vessels on their photographs. For example, sometimes they'll label a right brachiocephalic vein, but not the left. This leaves you (the suffering student) with the false impression that there is only one brachiocephalic vein. This is an idea that you might be comfortable with, because you probably reviewed the arteries first and learned that there is only one brachiocephalic artery in the cat. Be careful with text graphics!