Dong HC2

07/01/2016 Focus on RBCs: Figure 16-5c: Bone marrow Erythropoiesis 07/01/2016 Chapter 18 The Circulatory System: Blood Functions and properties of blood Plasma Blood cell production Erythrocytes Blood types Leukocytes Hemostasis Hematocrit Normal HCT: male = 46% female = 42% Abnormal HCT: > 56% polycythemia < 30% anemia Centrifuging blood forces formed elements to separate from plasma Hematocrit is % of blood volume that is composed of erythrocytes (RBCs) 07/01/2016 RBC Erythrocytes (RBCs) Disc-shaped cell with thick rim 7.5 M diameter & 2.0 m thick at rim Major function is gas transport lost all organelles during maturation and has biconcave shape which gives RBCs increased surface area/volume ratio increases diffusion rate of substances in & out of cell 33% of cytoplasm is hemoglobin (Hb) Hemoglobin is the red pigment that gives RBC its color O2 delivery to tissue and CO2 transport back to lungs cytoplasm contains enzyme, carbonic anhydrase (CAH) produces carbonic acid (H2CO3) from CO2 and water CAH has an important role in gas transport & pH balance 07/01/2016 RBC Structure Small and highly specialized disc Thin in middle and thicker at edge Figure 19–2d Erythrocytes on a Needle 07/01/2016 RBCs vs WBCs RBC an eosinophil Focus on RBCs: Figure 16-7a, b: Bone marrow 07/01/2016 RBC variation and irregularity anisocytosis poikilocytosis anisocytosis (aniso = unequal) various sizes poikilocytosis (poikilo = various) various shapes 07/01/2016 elliptocytes - heredirary elliptocytosis - iron def anemia - myelofibrosis with myeloid metaplasia - megaloblastic anemia - sickle cell anemia - normal ( “target” formation schistocytes (cell fragments) indication of hemolysis - megaloblastic anemia - severe burns - traumatic hemolysis - microangiopathic hemolytic anemia “helmet cell” (helmet cells, triangular cells) 07/01/2016 acanthocytes (irregular surface spicules) irregularly spiculated cells with bulbous/rounded ends of spicules - abetalipoproteinemia - liver disease echinocytes (crenated cells, burr cells) regularly contracted cells with smooth surface undulation - uremia - artifact - hyperosmolarity - discocyte-echinocyte transformation (may be associated with reduced ATP of RBCs) 07/01/2016 bite cells Removal (“bites”) of membrane by splenic macrophages - G6PD deficiency dacrocytes (teardrop cells) - thalassemia - myelofibrosis 10 07/01/2016 drepanocytes (sickle cells) - sickle cell anemia Sickle-Cell Diseased Erythrocyte 11 07/01/2016 rouleaux lined up RBCs in a row - multiple myeloma 12 07/01/2016 basophilic stippling irregular basophilic granules (remnants of RNA) fine stippling: •increased production of RBCs (reticulocytosis) coarse stippling: •lead poisoning •impaired Hgb syntheisis •megaloblastic anemia •other sever anemias sideroblast/siderocyte inorganic iron-containing granules (Pappenheimer bodies) - sideroblastic anemia ring intermediate sideroblasts sideroblast siderocyte abnormally trapped iron in mitochondria forming a ring around nucleus - post splenectomy 13 07/01/2016 Howell-Jolly body remnant of nuclear chromatin single: •megaloblastic anemia •hemolytic anemia •post splenectomy multiple: •megaloblastic anemia •other abnormal erythropoiesis Heinz bodies denatured hemoglobin - G6PD deficiency 14 07/01/2016 Hypochromia Pencil Cells 15