| Term | Definition |
| Arteries | Carry O2 Blood away from the heart; Exception to this this Pulmonary Artery |
| Arterioles | Smaller Vessels that branch off arteries that carry oxygenated blood away from the heart |
| Capillaries | Single cell thick, gas and nutrient exchange ocurrs; direction is away from the heart |
| Venule | Small vessels that bring blood toward the heart; contain valves and lead to veins |
| Veins | Large vessels that carry deoxygenated blood toward the heart; Exception is the Pulmonary Vein |
| Structure of Veins | Tunica Interna (Inner, smooth), Tunica Media (middle, smooth), Tunica Externa (outer, connective tissue) |