Term
| What is an advantage to the biconcave shape of red blood cells? |
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Definition
| Allows for greater surface area which allows for more efficient oxygen exchange |
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Term
| What problems could polycythemia cause? |
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Definition
| Polycythemia is an increase in the number of erythrocytes and can cause an increase in the viscosity of the blood which impairs flow through the capillaries. |
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Term
| What protein provides flexibility to erythrocyte membranes? |
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Definition
| Spectrin--a surface cytoskeletal protein forms the framework and allows for membrane flexibility. |
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Term
| What causes erythrocytes to take on a sickle shape? |
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Definition
| An inheritable disorder that causes a substitution of glutamic acid for valine at one hemoglobin site. |
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Term
| What causes hereditary spherocytosis and what are the consequences? |
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Definition
| Defects in spectin can result in spherocytosis which gives RBCs a spherical shape. The liver, spleen, and bone marrow remove the misshapen RBCs but this results in anemia. A splenectomy can relieve some of the symptoms. |
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Term
| T/F. Hemoglobin is formed by mature denucleated RBCs. |
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Definition
| False. Hemoglobin is only synthesize in immature erythrocytes. |
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Term
| What differentiates reticulocytes from mature erythrocytes? |
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Definition
| Reticulocytes are newly released erythrocytes that still contain rRNA that forms a network or reticulum in the cytoplasm. This network can be observed upon staining. |
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Term
| What structures remove worn out erythrocytes and how is it determined that an erythrocyte is to be destroyed? |
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Definition
| Macrophages of spleen, liver, and bone marrow. The worn out erythrocytes have a defective oligosaccharide that is attached to the integral protein of plasma membrane. |
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Term
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Definition
-Transferrin transports iron out of the blood
-In certain tissues free iron binds to apoferritin forming ferritin
-Ferritin is a protein that stores and later releases iron |
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Term
| What is the process by which heme is broken down? |
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Definition
-heme is catabolized into biliverdin
-biliverdin is converted to bilirubin
-bilirubin is secreted from the live as bilirubin glucuronide |
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Term
| What are Howell-Jolly bodies? When are they found? |
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Definition
| Howell-Jolly bodies are DNA fragments found in the cytoplasm of erythrocytes in some disease states. |
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Term
| Where are leukocytes active? How do they reach this area? |
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Definition
| Leukocytes are active in the connective tissue. When chemotaxins are detected leukocytes pass from venules and capillaries into CT via diapedesis. |
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Term
| What distinguishes granulocytes from agranulocytes? Which leukocytes are granulocytes? |
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Definition
| Granulocytes have two types of granules--specific and azurophilic. Neutrophils, eosinophils, and basophils are granular leukocytes. |
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Term
| What distinguishes agranulocytes from granulocytes? What leukocytes are considered granulocytes? |
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Definition
| Agranulocytes only have azurophilic granules. Agranulocytes are lymphocytes and monocytes. |
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Term
| What is the most common circulating leukocyte? What is its function? |
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Definition
| Neutrophils are the most common circulating leukocyte. Neutrophils function in the early phases of acute inflammation in extracvascular CT to phagocytose bacteria and 'smutz'. |
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Term
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Definition
| Remains of dead neutrophils, bacteria, digested tissue, and tissue fluid. |
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Term
| Once a neutrophil phagocytoses bacteria how is it broken down? |
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Definition
-Pseudopodia of the bacteria engulf the bacteria in vacuoles (phagosomes)
-Granules then fuse with phagosome and dump their products into the vacuole
-The pH of phagosomes is then lowered via proton pumps
-Azuophilic granules (lysosomes) dump their enzymes into phagosomes to destroy bacteria and are then ingested by lysosomal enzymes. |
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Term
| What substances of phagosomes can be used to break down bacteria? |
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Definition
-Superoxide anion free radical
-hydrogen peroxide
-myeloperoxidase and halide ions
-lysozyme to break down bacterial wall
-lactoferrin binds to iron which starves the bacteria
-hypochlorite which inactivated proteins |
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