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MD 07.00 Hematology . MD 07.01 Describe the Structure of the Blood MD 07.02 Analyze the Function of the Blood. Hematology. Hemo=Blood -ology=study of Hematology= Study of the blood, its structures and functions. Average adult = 8-10 pints of blood. Functions of the blood.
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MD 07.00 Hematology MD 07.01 Describe the Structure of the Blood MD 07.02 Analyze the Function of the Blood
Hematology • Hemo=Blood -ology=study of • Hematology= Study of the blood, its structures and functions. • Average adult = 8-10 pints of blood
Functions of the blood • Transports nutrients (from digestive system), oxygen (from the respiratory system), cellular waste products (from all the cells), and hormones (from the endocrine system). • Aids in distribution of heat (from the muscles to all parts of the body)
Functions of the blood • Regulates acid-base balance • Helps protect against infection
Composition of the blood • PLASMA – liquid portion of blood without cellular components (55% of blood volume) • CELLULAR ELEMENTS are red blood cells, white blood cells and platelets
PLASMA • Straw colored, contains 7 substances in solution: • Water (92%). • Blood proteins • Plasma proteins • Nutrients • glucose, fatty acids, cholesterol and amino acids from the digestive system.
PLASMA • Straw colored, contains 7 substances in solution: • Electrolytes • sodium (Na), potassium (K), and chloride (Cl). • Hormones, vitamins, enzymes • Metabolic waste products • picked up from cells to be taken to excretory organs.
PLASMA PROTEINS • FIBRINOGEN – necessary for blood clotting, synthesized in the liver. • ALBUMIN – from the liver, helps maintain blood’s osmotic pressure and volume. • GLOBULIN – from the liver and lymphatic system.
PLASMA PROTEINS • Two specific globulins are: • Prothrombin – helps blood coagulate. Formed in the liver. Vitamin K necessary for prothrombin synthesis. • Gamma Globulin – Helps in the formation of antibodies.
CELLULAR ELEMENTS OF BLOOD • Erythrocytes (RBC’s) • Leukocytes (WBC’s) • Thrombocytes (Platelets)
Erythrocytes (RBC’s) • Shape = biconcave discs. Caved-in on sides, with a thin center and thick margins. • RBC’S containhemoglobin – contain a red color • heme = iron globin = protein. • Function = transport oxygen to tissues and carbon dioxide away from cells
Erythrocytes (RBC’s) • Red cells travel through the lungs where they pick up molecules of oxygen from the alveoli. • O2 bonds with the hemoglobin = oxyhemoglobin. • Oxyhemoglobinis carried to tissues and oxygen released and taken into the cells. • CO2 picked up from the cells and carried back to lungs for excretion.
Erythrocytes (RBC’s) • Arterial blood – lots of oxyhemoglobin = bright red • Venous blood – lots of CO2 = dark crimson
What is carbon monoxide poisoning? What is carbon monoxide poisoning?
Carbon Monoxide Poisoning Carbon monoxide (CO) is an odorless gas present in the exhaust of gas engines and released when fuels are burned. CO rapidly combines with hemoglobin is exactly the same manner as oxygen. In the presence of CO the oxygen is unable to bind with hemoglobin because the CO crowds out the oxygen. Thus, the body cells are deprived of oxygen.
Carbon Monoxide Poisoning • Symptoms of CO poisoning: • Headache • Dizziness • Drowsiness • Confusion • Unconsciousness • Death.
ERYTHROPOIESIS • erythro=red -poiesis=formation • Manufacture of red blood cells • Occurs in bone marrow. Until adolescence, red marrow of all bones produce RBC’s. In adulthood, production occurs only in the short and flat bones.
Life of a RBC • RBC’s are enucleated (have no cell nucleus) therefore they live only 120 days • Old cells broken down by the spleen and liver. • The hemoglobin is broken down into its heme and globin components. • The heme (iron) is conserved to produce new RBC’s. • Normal hemoglobin values: men =14-18 gm,women = 12-16 gm
HEMOLYSIS • hemo=blood -lysis=destruction • Rupture or bursting of erythrocyte • Can be from a blood transfusion or disease (example Malaria). • Often causes chills and shaking in the patient.
LEUKOCYTES • (WBC’s) White Blood Cells • Larger than erythrocytes • Manufactured in both the bone marrow and lymphatic tissue. • 5 types • Normal leukocyte count = 3,200 – 9,800
Function of Leukocytes • Protect body against infection and injury : • Phagocytosis and destruction of pathogens (disease causing organisms). • Phagocytosis: process where white cells surround, engulf, and digest harmful pathogens • Production of antibodies. • Cleaning up of cellular remains at site of inflammation. • Walling off of infected areas.
Types of White Cells • WBC’s are first grouped into two large groups: • Granulocytes – formed in bone marrow (neutrophil, eosinophil, and basophil). Live only a few days. • Agranulocytes – absence of cytoplasmic granules (monocyte and lymphocyte) formed in lymph glands, nodes and bone marrow. Live a few days up to several years.
Granulocytes • Neutrophils – use enzymes to phagocytize pathogens. • Eosinophils – phagocytize remains of antibody reactions. Increased in allergic reactions. • Basophils – phagocytosis. Produce histamine and heparin (an anticoagulant)
Agranulocytes • Lymphocytes – produce and release antibodies and protect against formation of cancer cells. (T-lymphocytes are produced in thymus • Monocytes – are able to leave the blood and attach themselves to tissue. Wall off infected areas and isolate infection.
Diapedesis • when white cells move through capillary walls into neighboring tissue.
INFLAMMATION • Whenever living tissue is damaged, body responds by either neutralizing or eliminating the cause of damage. • Inflammation occurs when tissues are subjected to chemical or physical trauma, or invasion by pathogens. • Symptoms – redness, local heat, swelling and pain • Why??? Bacterial toxins, increased blood flow, collection of plasma in tissues (edema)
INFLAMMATION • What happens??? • Histamine is released by basophils, increasing the blood flow to the injured area as well as allowing plasma to move from the blood capillaries to the tissues (swelling) • Plasma entering area contains fibrinogen and monocytes, who begin to wall off the damaged areas.
INFLAMMATION • Neutrophils arrive, moving through the capillary walls (diapedesis). Begin phagocytosis of pathogens. • In most inflammations, Pus is produced – a combination of dead tissue, dead and living bacteria, dead leukocytes and plasma • If the damaged area is below the epidermis, an abscess forms.
INFLAMMATION • In many cases, chemical substances, pyrogens (pyro=fever, -gens=causing) are formed. • Pyrogens circulate through blood reaching hypothalamus, raising the body temperature. • Pyrexia – increase in body temperature by the hypothalamus in response to pathogenic invasion
INFLAMMATION • 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 megakaryocytes • Necessary for the initiation of the blood clotting process
COAGULATION • Cut or injury causes platelets and injured tissue to release THROMBOPLASTIN • Calcium ions and thromboplastin act upon PROTHROMBIN in the plasma to converts it to THROMBIN • Thrombin acts as an enzyme and changes FIBRINOGEN in the plasma into FIBRIN • Fibrin creates a mesh that traps red blood cells, platelets and plasma creating a blood clot.
PROTHROMBIN • dependent on Vitamin K for production. • Prothrombin and fibrinogen are produced in the liver. • Liver disease may therefore interfere with blood clotting.
ANTICOAGULANTS • Substances that prevent blood clotting. • Heparin is an anticoagulant.
BLOOD TYPES • Four major types of blood- A, B, AB and O • Inherited from parents • Determined by presence or absence of an ANTIGEN (a protein) on the surface of the red blood cell
B B B A A B A B B A A A B B B A A A A B B A AB A B B A O BLOOD TYPES • Type A has an “A” antigen. • Type B has a “B” antigen. • Type AB has both “A” and “B” antigens. • Type O has no antigens.
ANTIBODY • A protein in the plasma that will inactivate a foreign substance that enters the body. • In addition to having an antigen that determines the blood type, humans have antibodies that coordinate with the antigen.
B B B A A B A B B A A A B B B A A A b a b b a a a b b a a a a b b a ANTIBODIES • Someone with type A blood has b antibodies in their plasma. • Someone with type B blood hasa antibodies in their plasma.
Someone with type AB blood has no antibodies Someone with type O blood has a and b antibodies b a b b a a A B B a O b A AB A b B a B A ANTIBODIES
Blood Donation • Usually patients are given the SAME type of blood. • In emergency situations, a compatible type may be given. • In this case, the antigen on the RBC must not be the same as the antibody in the patient’s plasma.
ABO Compatibility • Antibodies in the plasma will react with the same antigen on the RBC. • The reaction cause the RBC’s to clump together (Agglutination). • These clumps will clog blood vessels, impeding circulation and possibly causing death. • The reaction will also cause Hemolysis • This is known as a Transfusion Reaction.
O ABO Compatibility • UNIVERSAL DONOR – OHas no antigens on the RBC’s • Because there is no antigen, there will be no reaction with whateverantibody is in the patient’splasma.
A B B A AB A B B A ABO Compatibility • UNIVERSAL RECIPIENT – AB Has no antibodies in the plasma. • Because there are no antibodies in the plasma, there will be no reaction with whateverantigen is on the donated RBC.
