2. Types of Blood Vessels 1.Arteries: Carry blood away from the heart Blood leaving heart starts off in large vessels called arteries Arteries become smaller in diameter as they branch out to spread through the body They are then known as arterioles

4. Pulse & Blood Pressure

5. Types of Blood Vessels 2. Capillaries: Carry blood from arterioles to venules When arterioles get small enough they turn into capillaries These tiny vessels are where nutrients and oxygen leave the blood and wastes (such as CO 2 ) enter blood No cell is more than 2 cells away from a capillary since all cells require oxygen and nutrients

6. Types of Blood Vessels 3. Veins: Carry blood to the heart Capillaries slowly get larger First turn to small veins called venules, then into larger veins Thin muscular walls, so less pressure Less pressure means pumping of blood by heart is not enough to move the blood back to heart

8. Types of Blood Vessels 4. Coronary Arteries: Supply heart muscles with blood!