1. B LOOD

2. C HARACTERISTICS OF B LOOD Heavier, thicker, more viscous than water Temperature of about 100.4 o F The average person has about 5-6qts (1 ½ gallons) of blood in their body. Makes up about 8% of your total body weight

3. C OMPOSITION OF B LOOD Blood is primarily made up of two things Formed Elements (Erythrocytes, Leucocytes, Thrombocytes) Cells Protein Molecules Solid Components Blood Plasma (Water, Solutes: dissolved substances) Water Dissolved substanes Liquid Components Hematocrit: Percentage of formed elements to plasma.

4. T HE F ORMED E LEMENTS Erythrocytes (Red Blood Cells) Main function to carry Oxygen Hemoglobin: oxygen carrying pigment of red blood cells (gives them their color) About 5,000,000/mm 3 Look like concaved discs (no nucleus) Live about 120 days (old cells destroyed in spleen, liver, marrow)

5. T HE F ORMED E LEMENTS Leucocytes (White Blood Cells) Main function is protection of the body 5,000 -10,000/mm 3 Live a few hours to a few days Two basic categories Granular (Neutrophils, Eosinophils, Basophils) Agruular (Lymphocytes{ Antibodies, T-cells, B-cells}, Monocytes)

6. T HE F ORMED E LEMENTS Thrombocytes (Platelets) Main function is to aid in blood clotting About 250,00-400,000/mm3 Live about 5-9 days

7. B LOOD P LASMA Yellowish (straw colored) liquid that remains after the formed elements are removed 91-92% Water 8-9% Dissolved substances Nutrients Gases Electrolytes Waste Products Enzymes Hormones Plasma Proteins (Albumins, Globulins, Fibrinogens)