Blood (10-28-2024) PDF

Blood (10 – 28 - 2024) I. Internal Transport A. All vertebrates and some invertebrates have a closed circulatory system; most invertebrates have an open system. B. Major role of blood is to maintain homeostasis. C. Functions: 1. Transports (nut...

Blood (10 – 28 - 2024) I. Internal Transport A. All vertebrates and some invertebrates have a closed circulatory system; most invertebrates have an open system. B. Major role of blood is to maintain homeostasis. C. Functions: 1. Transports (nutrients – plasma/oxygen – RBCs). 2. Maintains water content of tissue (plasma). 3. Maintains body temperature (plasma). 4. Protects against some diseases and infections (WBCs). II. Composition of Blood A. 150 pound person has five liters of blood and about 100,000 miles of blood vessels in his/her body. B. Blood = 55% fluid + 45% solid. 1. Plasma = fluid component. a. 92% water. b. Proteins (ex. fibrinogen). c. Salts (help to maintain an acid-base equilibrium). d. Sugars (especially glucose), amino acids, fatty acids, and glycerol. e. Hormones. f. Vitamins and minerals. g. Antibodies. h. Enzymes. i. Waste products. 2. Solid part = hematocrit = formed elements. a. Red blood cells (RBCs) = erythrocytes. 1. Formed in red and yellow marrow. 2. Lack a nucleus; look like Junior Mints. 3. Life span of 90 – 120 days. 4. 5,400,000 per cc of blood. 5. Contain hemoglobin – an iron-containing compound. 6. Function: Carry oxygen and some carbon dioxide. 7. Anemia – Disorder resulting from the lack of RBCs or the improper formation of RBCs. a. Lack of iron. b. Sickle cell anemia c. Excess bleeding d. Lead poisoning b. White blood cells (WBCs) = leukocytes 1. Formed in red marrow and lymph nodes. 2. May be multi-nucleated. 3. 1.5 – 2 times as large as RBCs. 4. Capable of changing their shapes. 5. Life span of several days; if there is an infection, perhaps only several hours. 6. 6,000 – 10,000 per cc of blood. 7. Functions: a. Some perform phagocytosis – engulf and destroy invading bacteria and viruses, foreign particles, and worn out RBCs. b. Some produce antibodies. 8. Leukemia – A disorder in which an excessively large number of WBCs are produced, some of which may be misformed. c. Platelets = thrombocytes. 1. Produced in the red marrow. 2. Lack a nucleus. 3. Life span: Several weeks. 4. 250,000 per cc of blood. 5. Function: Aid in the clotting of the blood. 6. Hemophilia – A disorder in which the blood does not clot properly. 7. Clotting of blood: a. Thromboplastin – A chemical released from the damaged cells of a blood vessel; it initiates the clotting process. b. Prothrombin – A chemical released from the liver when the blood volume in the body decreases. c. Calcium d. Vitamin K e. Thromboplastin + Prothrombin + Calcium + Vitamin K = Thrombin f. Thrombin + Fibrinogen (from the plasma) = Fibrin (protein matrix or net that traps the RBCs, WBCs, and platelets). g. Heparin - A substance produced by the liver that helps to dissolve blood clots in the bloodstream.