hematology

1. hematology functions

2. Four main functions: • Transport oxygen, nutrients, cellular waste products and hormones • Nutrients from digestive tract to cells, waste products to excretory organs, and hormones from secreting cells to other parts of the body • Aids in distribution of heat • Regulates acid-base balance • Helps protects against infection • BLOOD IS A VITAL FLUID TO OUR LIFE AND HEALTH • Read table 12-1 pg. 241

3. Plasma • Discussed in previous power point • Liquid part of blood • What makes up blood? • What is the purpose of each substance? • Plasma proteins • Which are…

4. Remember?Blood plasma • Straw-colored • Comprising about 55% of the blood volume! • Contains 6 substances: • Water • Plasma proteins (all are formed in the liver) • Nutrients • Electrolytes • Hormones, vitamins, and enzymes • Metabolic waste products

5. And…Plasma proteins • 3 proteins: • Fibrinogen • Necessary for blood clotting; without, a small cut or wound would bleed profusely • Serum albumin • Most abundant of all the plasma proteins • Helps to maintain the blood’s osmotic pressure and volume by providing “pulse pressure” needed to hold and pull water from the tissue fluid back into the vessels • Serum globulin • Also formed in the lymphatic system • Gamma globulin: helps in the making of antibodies • Prothrombin: helps blood coagulate • Vitamin K is necessary in aiding the process of prothrombin synthesis

6. erythrocytes • Also previously discussed • Contains hemoglobin • Transports O2 to tissues and CO2 away from cells • Red cells travel to lungs to get O2 and give up CO2, then to tissues to deliver O2 and pick up CO2 • Erythropoiesis • Manufacture of red cells in bone marrow • Hematopoiesis • Formation of blood cells • Occurs in what part of long bones? • All blood cells develop from stem cells (hematocytoblasts) • What was the life span of RBCs?

7. continued • Oxyhemoglobin • Formed when O2 combines with hemoglobin • Carbaminohemoglobin • Blood cells in the veins which are responsible for the dark, reddish-blue color • Hemolysis • Rupture of erythrocytes from blood transfusion or disease • CO poisoning • Serious and sometimes fatal • Compete with O2 when attaching to hemoglobin • Causes the cells to be _______________________________. • Symptoms: HA, dizziness, drowsiness, and unconsciousness

8. leukocytes • Do you remember covering this? You should…  • Fight infection • Phagocytosis – white cells surround, engulf and digest harmful bacteria • Basophils produce heparin – an anticoagulant • Diapedesis– when white cells move through capillary walls into neighboring tissues

9. Inflammation • Body’s reaction to chemical and physical trauma (cut or heat) • Pathogenic – disease producing microorganisms that can cause infection • Examples: bacteria, fungi, protozoa, and viruses • Symptoms – redness, local heat, swelling, and pain • Why? Due to irritation by bacterial toxins, increased blood flow, congestion of blood vessels, and collection of plasma in tissues (edema) • See figure 12-2 pg. 246

10. Inflammation terms • Pus • Cream-colored liquid formed from a combination of dead tissue, dead and living bacteria, dead leukocytes, and blood plasma • Abscess • Pus-filled cavity below the epidermis • Pyrogens • Chemicals release when there is inflammation • Circulate to the hypothalamus and affect the temperature control center • Pyrexia • Raise in body temperature (fever) caused by pyrogens • Leukocytosis • Increase in the white blood cell count, above 10,000 • Leukopenia • Decrease in the normal amount of WBCs

11. Thrombocytes(platelets) • Again, covered previously • Synthesized in red marrow • Necessary for the initiation of the blood clotting process • What is the normal count? • Is it the smallest or largest of the solid components of blood? • What is a “platelet plug”?

12. coagulation • Blood clotting • Depends on thrombocytes • Clotting must occur to stop bleeding when there is a cut or other injury • When a blood vessel or tissue is injured, platelets and injured tissue release thromboplastin • Chain reaction follows and involves the release of thromboplastin, prothrombin, thrombin and fibrinogen • Fibrin creates a mesh that traps red blood cells, platelets and plasma, creating a blood clot • Anticoagulants prevent blood clotting and must be neutralized • Antithromboplastin and antiprothromin (heparin) • *Prothrombin and fibrinogen are manufactured in the liver so serious liver disease may interfere with blood clotting process*

13. Clotting time • Time it takes for blood to clot • Clotting time for humans is from 5-15 minutes • Useful to know a patient’s clotting time before surgery • See figures 12-3 and 12-4 on pages 248 and 249 regarding clotting.

14. Blood types • Four major types, determined by presence or absence of an antigen on the surface of the red blood cell • A, B, O, AB • Inherited from parents • Determined by the presence (or absence) of the blood protein antigen (found on the surface of RBCs) • Type O has neither A or B and AB has both • Antibody – a protein in the plasma that will inactivate a foreign substance that enters the body • Someone with type A blood has B antibodies • Type B blood has A antibodies • Type AB blood has no antibodies • Type O blood has A and B antibodies • Universal donor: O- • Universal recipient: AB+ • See table 12-4 page 249

15. Rh factor • Red cells may also contain Rh factor • Rh positive (+) are those with the factor • Rh negative (-) are those without Rh factor • 85% or North Americans are Rh + • READ Rh Factor page 248-249