The Function of Blood

The Four Components of Blood Red Blood Cells White Blood Cells Platelets Plasma

Blood is the largest organ in the body (tissue) because it travels throughout the blood vessels.

The flow of blood through the body, beginning with the heart is: Aorta Arteries Arteriole Capillary* Venuoles Vein Vena cava

Blood has 7 Functions 1. Maintains Homeostasis — helps keep pH and temperature at ideal level. 2. Regulate Temperature — distributes heat to every area of the body 3. Maintain pH — has buffers that keep pH at ~7.4and keeps fluid and electrolytes balanced 4. Hormone Transport — to organs where they serve as signals that influence cellular metabolism

Blood has 7 Functions 5. Helps Fight Infection — white blood cells identify and destroy invaders 6. Gas and Nutrient Transport — Brings O2 & sugars to cell and take CO2 & waste away 7. Prevents Hemorrhage — platelets form clots in damaged areas

The pumping of the heart sends blood via arteries towards the capillaries where gas/nutrient exchange takes place across the thin capillary walls. Capillary is the smallest of all vessels composed of only 1 layer of epithelial cells. (Very Fragile)

(force caused by uneven solute conc.) (created by heart pumping) Capillary Exchange Osmotic pressure (force caused by uneven solute conc.) Blood Pressure (created by heart pumping) ARTERIOLE VENUOLE salt water oxygen sugar CO2 water Nitrogenous Wastes

Questions What drives nutrients/oxygen to diffuse out of the capillary on the arteriole end? Blood pressure What drives the waste products in the cell to diffuse into the capillary on the venous end? Osmotic pressure