Health Science Technology II Dr. Wood Blood Health Science Technology II Dr. Wood

Functions of blood Transportation Heat regulation

Composition of blood Made of plasma & formed elements Plasma: fluid portion of blood Formed elements Red blood cells (erythrocytes) White blood cells (leukocytes) Platelets (thrombocytes)

Hematocrit or Packed Cell Volume (PCV) Percent of red blood cells in whole blood Buffy coat (less than 1%): white blood cells & platelets

Erythrocytes (RBCs) Mature RBC has no nucleus, ribosomes, mitochondria Small biconcave discs Primary component: hemoglobin (1/3 of cell volume) Transport oxygen & carbon dioxide

Destruction of RBCs Life span of RBC is about 105-120 days Macrophages in lining of blood vessels in spleen & liver phagocytose old or damaged RBC

Erythrocytosis/Polycythemia Excess of red blood cells Relative polycythemia: patient appears to have an excess of RBCs due to ______. Absolute polycythemia Primary polycythemia Secondary polycythemia: stimulated by increased erythropoietin

Anemia Number of RBCs or hemoglobin is low Types: Iron deficiency anemia Vitamin deficiency anemia Sickle cell anemia Hemolytic anemia

Iron Deficiency Anemia Cells are microcytic & hypochromic Normocytic & normochromic: Normal RBCs

Sickle cell anemia

Leukocytes (WBCs) 5 types All have nuclei Larger than RBCs Granulocytes (have large granules in cytoplasm) Neutrophils Eosinophils Basophils Agranulocytes Lymphocytes Monocytes

Neutrophils About 65% of the total WBC count Multilobed nucleus Small light purple granules in cytoplasm Function: cell defense by phagocytosis of microorganisms Life span: hours to 3 days

Neutrophilia Increase in number of neutrophils Often secondary to an acute bacterial infection

Neutropenia Abnormally low number of neutrophils Resulting from: Decreased production: drug toxicity, virus, etc Increased destruction Pooling: overwhelming infections

Eosinophils Usually 2 lobed nucleus Large orange-red staining granules Function: cellular defense usually against parasites & involved in allergic reactions Life span: 10-12 days

Eosinophilia Increased number of eosinophils Allergies Parasitic infection

Basophils Usually 2 lobed nucleus Sparse, large purple staining granules Least numerous WBC Function: secrete heparin & histamine Life span: hours to 3 days

Lymphocytes Smallest of WBC, about 25% of total WBC count Large spherical nuclei with scant pale blue cytoplasm Life span: days to years

Monocytes Largest of the WBC Kidney bean shaped nuclei with large quantities of blue-gray cytoplasm Phagocytic cell capable of ingesting bacteria, debris, cancerous cells In tissue called macrophages Life span: months

Terms Lymphocytosis Lymphopenia or lymphocytopenia Basophilia Monocytosis Monocytopenia

Platelets Small, nearly colorless, irregular Important in clotting

Platelet Terms Thrombocytopenia Thrombocytosis

Blood Types Refers to the type of antigens present on RBC membrane Important blood antigens: A, B, Rh Agglutinins: antibodies dissolved in plasma that react with specific blood group antigens

ABO System Type A: Antigen A on RBCs Type B: Antigen B on RBCs Type AB: Antigen A & B on RBCs Type O: Neither A nor B on RBCs Plasma never contains Ab against Ag present on it own RBCs Plasma does contain AB against those Ag not present on its RBCs

The Rh System Rh positive: Rh antigen is present on RBCs Rh negative: RBCs have no Rh antigen Blood does not normally contain anti-Rh antibodies except thru previous transfusion or pregnancy

Blood Plasma 90% water, 10 % solutes Most of the solutes are proteins (formed by liver) Albumin: help maintain osmotic balance Globulins: immune mechanism Fibrinogen: blood clotting Remaining solutes are food substances, metabolic products, respiratory gases, hormones, etc