Mammalian Blood Vessels

Arteries Muscular vessels that always carry oxygenated blood away from the heart, with the exception of the pulmonary arteries that always carry deoxygenated blood from the heart to the lungs.

Different Types of Arteries: Aorta largest artery in the body moves blood at 1.6 km/h Arterioles (smaller arteries) no thicker than a hair Carry oxygenated blood from arteries to capillaries

Capillaries carry oxygenated blood microscopic, 1 cell thick, leaky blood vessels which allow gases and fluids to exit and enter (red blood cells (RBC) are too big to pass)

so small that only one RBC can pass at a time capillaries are no further than 50 microns away from any cell Arteriole Capillary Artery

Capillaries: http://www.youtube.com/watch?v=Q530H1WxtOw

Vena Cava the largest of the veins in the body it takes all the deoxygenated blood and dumps it into the right atrium

Veins carry deoxygenated blood to the vena cava have many one-way flap-like valves that carry blood back to the heart

- Carry deoxygenated blood back to the veins Venules - Carry deoxygenated blood back to the veins

Path of Blood Flow: Vena Cava Aorta Veins Arteries Venules Arterioles Capillaries