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MLS 332 unit 2
| Term | Definition |
|---|---|
| what is the function of the erythrocyte? | To transport oxygen from the lungs to the tissues and carbon dioxide from the tissue to the lungs |
| what is the lifespan of the erythrocyte? | 120 days |
| What are the dimensions of the erythrocyte? | Biconcave disc 7-8mcM in diameter; MCV 80-100FL |
| how does the concentration for erythrocytes change depending on age? | Highest at brith, then gradually decreases |
| how does the concentration of erythrocytes change based on sex? | higher in males than females |
| how does the concentration of erythrocytes change based on geographic location? | higher in high altitudes |
| list the specialized functions that the erythrocyte membrane provides for the cell | special erythropoiesis receptors, regulate RBC metabolism, takes in vital components, release metabolic waste, balance exchange of ions, provides antigenic expression, and responsible for strength and deformability |
| describe the composition of the erythrocyte cell membrane including major lipids and proteins | 52% proteins, 40% lipids, 8% carbohydrate |
| main function of cholesterol | surface area and permeability |
| list the phospholipids in the cell membrane | PE-inside PS-inside PI-inside PC- outside SM-outside |
| what are the functions of the glycophorins? | zeta potential and anchoring fro skeletal proteins |
| hat is zeta potential? | the overall net negative charge of the red cell |
| what are the functions of the transport proteins? | chloride/bicarbonate exchange, major binding site, anchoring the skeleton- (MAIN FUNCTION) |
| where are the peripheral proteins located? | cytoplasmic side of membrane |
| what do horizontal actions do? | support lipid bilayer |
| what do vertical actions do? | attach protein skeleton |
| Which protein is the horizontal action? | Spectrin |
| which protein is the vertical action? | ankrin |
| what is the function of spectrin? | deformability; spring like, alpha and beta heterodimers |
| what is the function ankrin | bind spectrin to band 3; strengthened bu band 4.2 (band 4.2 is like glue) |
| why do RBC's rely on various energy- dependent processes? | to maintain cation pumps, hb iron in the reduced state, membrane integrity/ deformability |
| what is the function of the glycolytic pathway? | provides the red blood cell with ATP (energy) by breaking down glucose; metabolizes 90-95% of RBC glucose |
| what are the products of the glycolytic pathway> | net gain of 2 ATP per glucose |
| what is the function of the hexose monophosphate shunt (HMP)? | provide NADPH and reduced glutathione (GSH) , maintain hemoglobin in the reduced, functional state , and safeguard vital cellular enzymes from oxidation |
| what is the function of the raport-leubering shunt? | Controls the amount of 2,3-BPG produced, which in turn affects the oxygen affinity hemoglobin Regulates oxygen delivery to the tissue |
| what is the mechanism of the raport-leubering shunt? | Sacrifices the production of one of the 2 ATP molecules produced via glycolysis to make 2,3 BPG |
| what is the function of the methemoglobin reductase pathway? | Protects hemoglobin from oxidation by using NADH (from glycolytic pathway) and methemoglobin reductase (cytochrome b5); Maintains methemoglobin levels at 2%, as opposed to 20-40% in its absence |
| what is the mechanism of the methemoglobin reductase pathway? | Methemoglobin reductase and NADH (produced by glycolytic pathway) reduce methemoglobin back to hemoglobin |
| summarize the erythrocyte deformability | 1. biconcave shape 2. internal viscosity 3. viscoelastic membrane |
| explain extravascular destruction characteristics | occurs mainly in the spleen; site of 90% of all RBC destruction |
| what are the intravascular destruction characteristics | in bloodstream |
| explain the function of EPO | stimulate erythropoiesis |
| state the origin and cellular effects of EPO | kidneys; prevent apoptosis, and increase erythropoiesis to 5 to 10 fold |
| what are the hemoglobin reference intervals for males? | 14.0-17.4 g/dL |
| what are the hemoglobin reference intervals for females? | 12-16 g/dL |
| what is considered a critical value for hemoglobin? | <6.6 g/dL |
| describe the hemoglobin molecule structure | a large tetrameric molecule, with 4 subunits (heme and globin chains), |
| list the alpha-like chains | a, Z |
| list the beta like chains | E, Y, S, B |
| alpha chains are made on | chromosome 16 |
| beta chains are made on | chromosome 11 |
| list the types of hemoglobin normally found in adults and their approximate concentrations | HbA-95%, HbA2- 1.5-3.7%, HbF- less than 2% |
| list the types of hemoglobin normally found in newborns along with their approximate amounts | |
| define hemoglobin A1C and what it is used for diagnostically | to measure how well someone is managing their blood glucose levels |
| define oxygen affinity | The ease at which hgb binds and releases oxygen |
| what shifts the oxygen dissociation curve to the left? | Decreased H+, decreased CO2, decreased temperature, decreased 2,3-BPG |
| what shifts the oxygen dissociation curve to the right? | increased H+, Increased CO2, Increased temperature, Increased 2,3-BPG |
| what does 2-3BPG do? | decrease O2 affinity- encourages release to tissues |
| is intravascular or extravascular destruction more dominant? | extravascular |
| where is extravascular hemolysis? | spleen, liver, bone marrow (macrophages are the cell) |
| where is intracellular hemolysis? | blood vessels |
| state the laboratory detections of extravascular hemolysis | increased urine/ fecal urobilinogen, increased unconjugated bilirubin in plasma |
| state the laboratory detections of intravascular hemolysis | □ Hemoglobinuria □ Hemosiderinuria □ hemoglobinemia □ Methemoglobinemia □ Decreased haptoglobin/ hemopexin □ increased unconjugated bilirubin □ Increased LDH (lactate dehydrogenase) |
| Ferrous iron | Fe++ |
| Ferric iron | Fe+++ |
| each heme molecule= | 1 oxygen molecule |
| what type of hemoglobin is in fetal? | HbF, HbA, HbA2 |
| What percent is HbA in adults? | more than 95% |
| what percent is HbA2 in adults | 1.5-3.7% |
| what percent is HbF in adults | less than 2% |
| Oxyhemoglobin | relaxed (R) structure with high O2 affinity |
| deoxyhemoglobin | tense (T) structure with low O2 affinity |
| what does a shift to the left of the oxygen dissociation curve mean? | higher affinity; oxygen will bind more easily |
| What does a shift to the right of the oxygen dissociation curve mean? | lower affinity; oxygen will release more easily |
| define allosteric | structure and function are affected by other molecules |
| list the non-functional hemoglobins | methemoglobin, sulfhemoglobin, carboxyhemoglobin |
| describe the characteristics of methemoglobin | Ferric iron, loss of reducing enzymes (NADPH), globin chains, toxic substances, cyanoisis, dark brown blood |
| describe the characteristics of sulfhemoglobin | sulfur + Hgb, environmental exposure, greenish blood |
| describe the characteristics of carboxyhemoglobin | carbon monoxide + Hgb, 200x affinity, cherry red blood |
| What property of oxygen is responsible for the rate at which it diffuses across cellular membrane? | partial pressure |
| Which of the following would shift the oxygen dissociation curve to the right? | - Increased 2,3-BPG |
| Which of the following hemoglobin type(s) is normally found in a healthy adult? | Hgb A, Hgb A2, and Hgb F |
| When present, the molecule 2,3-BPG is responsible for ________________ oxygen affinity in the RBC. | decreasing |
| What is the name of the plasma protein responsible for binding free hemoglobin during intravascular hemolysis? | haptoglobin |
| Which of the following findings would indicate intravascular hemolysis in a patient? | hemoglobin in the urine |
| define poikilocyte | change in shape of RBC |
| define anisocytosis | variation in size of RBC's; correlates to red blood cell distribution width |
| what is the normal MCHC of a mature erythrocyte | 32-36 g/dL |
| explain how to assess the size of mature red blood cells | compare to small lymphocyte nucleus; normocytic- 80-100fL larger is macrocytic, smaller is microcytic |
| explain how to assess hemoglobination of mature red blood cells | assess diameter of central pallor; normochromic (32-36 g/dL) larger is spherocytic and smaller is hypochromic |
| RBC size correlates to... | MCV |
| hemoglobination correlates to... | MCHC |
| what is the mechanism of formation of Acanthocytes? | excess distribution of cholesterol in outer layer of membrane |
| what is the mechanism of formation of Codocytes | increased surface area to volume ratio |
| what are the associated diseases of acanthocytes? | alcoholic liver disease |
| what are the associated diseases of codocytes? | hemoglobinopathies, thalassemias |
| what are the associated diseases of dacryocytes? | primary myleofibrosis (PMF), thalassemias |
| what is the mechanism of formation of dacryoctes? | result of prolonged squeezing through a small space |
| what is the mechanism of formation drepancoytes? | polymerization of hemoglobin S into rods stretches the cell and increased fragility |
| what are the associated diseases with drepancoytes? | sickle cell disorders |
| what is the mechanism of formation of echinocytes? | increased area of the outer layer membrane in comparison to the inner layer |
| what are the associated diseases with echinocytes? | liver disease, uremia, pyruvate kinase deficiency etc... |
| what is the mechanism of formation of eliptocytes? | unknown; thought to be alterations in the membrane skeleton |
| what are the associated diseases with eliptocytes? | hereditary elliptocytosis, iron deficiency anemia |
| what is the mechanism of formation of oval macrocytes? | abnormal maturation and nuclear/ cytoplasmic asynchrony of developing bone marrow cells |
| what are the associated diseases with oval macryocytes? | megaloblastic anemias |
| what is the mechanism of formation of schistocyte fragments? | mechanical damage to red blood cells |
| what is the mechanism of formation of schistocyte bite cells? | splenic pitting |
| what is the mechanism of formation of schistocyte keratocytes? | impalement of RBC on fibrin strand |
| what are the associated diseases with schistocyte fragments? | hemolytic anemias |
| what are the associated diseases with schistocyte bite cells? | G6PD deficiency |
| what are the associated diseases with schistocyte keratocytes? | hemolytic anemias, glomerularnephritis |
| what is the mechanism of formation of spherocytes? | decreased surface area to volume ratio |
| what are the associated diseases with spherocytes? | hereditary spherocytosis |
| what is the mechanism of formation of stomatocytes? | increased lipid content or area of the inner layer of cell membrane as compared to outer layer |
| what are the associated diseases of stomatocytes? | often artifact, hereditary stomatocytosis |
| what is the composition of basophilic stippling? | aggregates of ribosomes (RNA) and mitochondria |
| what are the associated diseases of basophilic stippling? | sideroblastic anemias, lead poisoning |
| what is the composition of cabot rings? | remnant microtubules of the mitotic spindle |
| what are the associated diseases of cabot rings? | severe anemias, dyserythropoiesis |
| what is the composition of howell-jolly bodies? | DNA |
| what are the associated diseases of howell-jolly bodies? | post splenectomy |
| what is the composition of heinz bodies? | denatured, precipitated hemoglobin |
| what are the associated diseases with heinz bodies? | G6PD deficiency |
| heinz bodies are only visible on ... | supervital stain |
| what is the composition of pappenheimer bodies? | iron and protein |
| what are the associated diseases of pappenheimer bodies? | sideroblastic anemia, sickle cell anemia |
| what is the mechanism of formation of hemoglobin C crystals? | intracellular crystallization of hgb C |
| what is the associated disease of hemoglobin C crystals? | hemoglobin C disease |
| what is the mechanism of formation of agglutination? | caused by antigen/ antibody interactions between sensitized red blood cells |
| what is the associated diseases with agglutination? | autoimmune anemias, cold autoimmune hemolytic anemia |
| what is the mechanism of formation of rouleaux? | excess plasma proteins cause RBC to be sticky |
| what are the associated diseases with rouleaux? | multiple myeloma |
| what is the mechanism of formation of polychromasia? | bone marrow releases red blood cell precursor earlier than normal |
| what are the associated diseases of polychromasia? | various anemias, normal newborns |
| what is the mechanism of formation of nucleated red blood cells? | bone marrow releases red blood cell precursor earlier than is normal |
| describe the components of the red blood cell morphology scan | RBC indices, consider RDW, Size and hemoglobination, anisocytosis, poikilocyte, other RBC changes |
| how do you calculate MCV? | hematocrit/RBC count x10 |
| how do you calculate MCH? | hemoglobin/RBC count x10 |
| how do you calculate MCHC? | hemoglobin/ hematocrit x100 |
| RDW correlates to... | anisocytosis |
| an average of 1-3 poikilocytes per field of view on a smear would report as | few |
| average of 4-6 poikilocytes per field of view on a smear would report as | moderate |
| average of >6 poikilocytes per field of view on a smear would report as | many |
Created by:
marynelson01
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