HematologyThe Study of blood

• Average adult = 8-10 pints of blood

• Composition:– PLASMA – liquid

portion of blood without cellular components

– Serum – plasma after a blood clot is formed

– Cellular elements are red cells, white cells and platelets

PLASMA

• Straw colored, contains – – Water– Blood proteins– Plasma proteins

• FIBRONOGEN – 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.

Plasma

– Nutrients– Electrolytes– Hormones, vitamins, enzymes– Metabolic waster products

Erythrocytes-Red Blood Cell

• Shape = biconcave discs• RBC• HEMOGLOBIN – gives red

color, heme is iron and globin is protein.

• Function = transports oxygen to tissues and carbon dioxide away from cells

• Normal – men =14-18 gm, women = 12-16 gm

Function of Hemoglobin

• 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.

White Blood Cells – LEUKOCYTES

• Larger than erythrocytes• 5 types• Normal leukocyte count

= 3,200 – 9,800 • Types of White Cells• Neutrophils• Eosinophils• Basophils• Lymphocytes• Monocytes

Leukocytes

• Basophils produce HEPARIN – an anticoagulant 

• DIAPEDESIS – when white cells move through capillary wall into neighboring tissue.

• PHAGOCYTOSIS – process when white cells surround, engulf, and digest harmful bacteria.

Inflammation

• Body’s reaction to chemical or physical trauma

• PATHOGENIC – disease producing microorganisms can cause inflammation

• Symptoms – redness, local heat, swelling and pain

• Why? Bacterial toxins, increased blood flow, collection of plasma in tissues (edema)

• HISTAMINE increases the blood flow to the injured area

• PUS produced – 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

Abscess

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 (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.

• ANTICOAGULANTS – prevent blood clotting

• HEPARIN = antiprothrombin• PROTHROMBIN – dependent on

Vitamin K

Blood Facts

• There are about one billion red blood cells in two to three drops of blood. For every 600 red blood cells, there are about 40 platelets and one white cell.

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

• ANTIBODY – 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 Types

• UNIVERSAL DONOR – O

• UNIVERSAL RECIPIENT – AB

• Red cells also may contain Rh factor

• If you have it, you’re Rh +

• If you don’t, you’re Rh –

RH Incompatibilties

Disorders of the Blood

• ANEMIA• Deficiency in

number or % of red cells 

IRON-DEFICIENCY ANEMIA

• Usually in women, children and adolescents

• Deficiency of iron in the diet causing insufficient hemoglobin synthesis

• Treat with iron supplements and green, leafy vegetables

APLASTIC ANEMIA

• Bone marrow does not produce enough red and white blood cells

• Caused by drugs or radiation therapy

SICKLE CELL ANEMIA

• Chronic blood disease inherited from both parents

• Causes the red cells to form in abnormal sickle shape

• Sickle cells break easily and carry less oxygen

• Occurs primarily in blacks

• Treatment – blood transfusions

POLYCYTHEMIA

• Too many red blood cells are formed

• May be a temporary condition that occurs at high altitude

EMBOLISM

• Air, blood clot, cancer cells, fat, etc. that is carried by the bloodstream until it reaches an artery too small for passage

• Also known as a “moving blood clot”

THROMBOSIS

• The formation of a blood clot in a blood vessel

• The blood clot is a THROMBUS

HEMATOMA

• Localized clotted mass of blood found in an organ, tissue or space.

• Caused by an injury that can cause a blood vessel to rupture

HEMOPHILIA

• Hereditary• Missing clotting

factor• Blood clots slow or

abnormally• Sex-linked –

transmitted genetically from mothers to sons

• Treat with missing clotting factor, avoid trauma

THROMBOCYTOPENIA

• Not enough platelets

• Blood will not clot properly

LEUKEMIA

• Malignant condition• Overproduction of

immature white blood cells

• Hinders synthesis of red cells