HEMATOLOGY

Blood Average adult = 8-10 pints of blood Functions of the blood:   Functions of the blood:  Transports nutrients, oxygen, cellular waste products, and hormones Aids in distribution of heat Regulates acid-base balance Helps protect against infection

Composition of Blood What is blood made up of? Plasma—liquid portion of the blood Serum – plasma after a blood clot is formed Cellular elements are red cells (erythrocytes), white cells (leukocytes) and platelets(thrombocytes)

Plasma Straw colored, contains – Water Blood proteins Plasma proteins Nutrients Electrolytes Hormones, vitamins, enzymes Metabolic waste products

Plasma Proteins FIBRINOGEN – necessary for blood clotting, synthesized in the liver ALBUMIN – from the liver, helps maintain blood’s osmotic pressure and volume PROTHROMBIN – a globulin which helps blood coagulate. Vitamin K necessary for prothrombin synthesis.

Erythrocytes Red Blood Cells Shape = biconcave discs Contains HEMOGLOBIN – gives red color

Hemoglobin Made up of Heme and globin Heme=iron Globin=protein Function = transports oxygen to tissues and carbon dioxide away from cells Normal – men =14-18 gm, women = 12-16 gm

How Hemoglobin Works Red cells travel through the lungs where O2 is carried to tissues and released CO2 picked up and carried back to lungs for exchange Arterial blood – lots of oxygen = bright red Venous blood – lots of CO2 = dark crimson

Erythropoiesis Manufacture of red blood cells Occurs in bone marrow Red cells live 120 days Old cells broken down by the spleen and liver

Hemolysis rupture or bursting of erythrocyte, can be from a blood transfusion or disease.

Leukocytes White Blood CellsLarger than erythrocytes 5 types: neutrophils, eosinophils, basophils, lymphocytes, monocytes Normal leukocyte count = 3,200 – 9,800

Leukocytes Fight Infection Phagocytosis--process when white cells surround, engulf, and digest harmful bacteria.

Diapedesis when white cells move through capillary wall into neighboring tissue

Inflammation Body’s reaction to chemical or physical trauma PATHOGENIC – (disease producing) microorganisms can cause inflammation Symptoms – redness, local heat, swelling and pain HISTAMINE increases the blood flow to the injured area

Terms Related to Inflammation PUS – a combination of dead tissue, dead and living bacteria, dead leukocytes and plasma ABSCESS – pus-filled cavity below the epidermis PYREXIA – increase in body temperature by the hypothalamus – in response to pathogenic invasion

Problems with Leukocyte Numbers LEUKOCYTOSIS – increase in the number of white cells in response to infection LEUKOPENIA – decrease in number of white cells due to chemotherapy or radiation

Thrombocytes Platelets Smallest of solid components of blood Synthesized in red marrow Not cells – fragments of cells Necessary for the initiation of the blood clotting process

Coagulation (Clotting) Cut or injury  platelets and injured tissue release THROMBOPLASTIN  act on PROTHROMBIN in plasma  + Calcium ions converts to THROMBIN  the thrombin acts as an enzyme and changes FIBRINOGEN  FIBRIN creating a mesh that traps red blood cells, platelets and plasma creating a blood clot.

Terms Related to Coagulation ANTICOAGULANTS – prevent blood clotting HEPARIN = antiprothrombin PROTHROMBIN—necessary for clotting – dependent on Vitamin K

Blood Types Four major types of blood- A, B, AB and O Inherited from parents Determined by presence or absence of an ANTIGEN on the surface of the red blood cell

Antibodies a protein in the plasma that will inactivate a foreign substance that enters the body.   Someone with type A blood has b antibodies Someone with type B blood has a antibodies Someone with type AB blood has no antibodies Someone with type O blood has a and b antibodies

Blood Donation UNIVERSAL DONOR – O UNIVERSAL RECIPIENT – AB Red cells (erythrocytes) also may contain Rh factor If you have it, you’re Rh + If you don’t, you’re Rh –