FUNCTIONS HEMATOLOGY

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

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…

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

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

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?

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

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

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

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

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”?

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*

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.

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

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