AP Chp. 17 Blood
State the cell that is the source of all formed elements in the blood. Define reticulocyte and state what a reticulocyte count indicates.
A hemocytoblast is the source of all formed elements. Increased Hb content triggers release of nucleus and organelles, biconcave shape occurs. A reticulocyte is a young RBC. A reticulocyte count (1-2%) indicate RBC formation rate.
Define anemia. State the three causes of anemia and give examples of each of these causes. Define hemorrhagic, hemolytic, aplastic, iron-deficiency, pernicious, and sickle-cell anemias. Define thalassemia.
Anemia means "lacking blood". One cause could be there are too few RBCs. Hemorrhagic = blood loss, Hemolytic = excessive destruction, Aplastic = bone marrow failure. Decreased Hb content is also a problem. Iron-deficiency anemia refers to inadequate iron intake/absorption. Pernicious anemia occurs when vitamin B12 is not absorbed due to an intrinsic factor deficiency. Finally, a person can have abnormal Hb. Thalassemia, or "sea blood" is genetic, where 1 of globin chains is faulty or absent. Sickle-cell anemia is a genetic mutation in an amino acid. Defective gene is protective against malaria. Hydroxyurea is a treatment.
State some physical characteristics of blood and the normal blood values of males and females. Describe blood plasma and state the functions of albumin in plasma. Describe the three functions of blood.
Blood is sticky, opaque, and has a metallic/salty taste. It is bright red if oxygen rich, and dark ret if oxygen poor. It is slightly alkaline. A female has 4-5L of blood while a male has 5-6L. Blood DISTRIBUTES (delivers oxygen and nutrients), REGULATES (maintains body temp, normal pH and fluid volume), and PROTECTS (prevents blood loss, prevents infection). Blood plasma is sticky and made of dissolved solutes. Albumin is 60% of blood protein, and it shuttles molecules, buffers, and maintains osmotic pressure.
Identify human ABO blood groups by description or depiction of the antigens and antibodies that a patient contains. Describe the Rh blood grouping and state a major difference between the Rh and ABO grouping systems. Describe a transfusion reaction.
Blood type is based on the presence of antigens. An antibody in the blood stream will bind to the antigen. Unlike the ABO system, anti-Rh antibodies are not spontaneously formed in the blood of Rh- individuals (only after mismatched transfusion). A transfusion reaction occurs when the donor's red blood cells are attacked by the recipients plasma antibodies. Agglutination leads to clogging of blood vessels. RBCs can be lysed immediately if severe.
Define fibrinolysis. Identify factors that limit or prevent undesirable clot formation. Compare and contrast thrombus and embolus.
Fibrinolysis gets rid of clots after healing is done. It begins after 2 days and continues until clot is dissolved. Clot is actually dissolved by plasmin, a enzyme from plasminogen tPA. Clot growth is limited due to removal of clotting factors by the blood or inhibition of the clotting factors (thrombin bound, inactivation by antithrombin III, heparin). Heparin and prostacyclin are secreted by endothelial cells to prevent platelet adhesion. Vitamin E is an anticoagulant. A thrombus is a clot in an unbroken blood vessel and an embolus is a clot that that has broken away and floats freely in the bloodstream.
Define the terms granulocytes and granulocytes and state the relative abundances of the granulocytes and agranulocytes.
Granulocytes (NEB) are spherical in shape, are larger and their cytoplasmic granules stain with Wright's stain. Agranulocytes lack visible cytoplasmic granules and have spherical or kidney shaped nuclei.
Describe a hemoglobin molecule.
Hb binds easily, reversibly to oxygen. Normal ranges are 12-16 for a female and 13-18 for a male. A protein globin bound to a red heme pigment. Made of 4 peptide chains, with an iron in the center.
Define Hematocrit, state the normal ranges for males and females, and describe how a hematocrit is determined.
Hematocrit is the percentage of whole blood volume made up of erythrocytes. Male =47/5%, Female = 42/5%. Hematocrit is determined by a centrifuge, heavier formed elements go to the bottom while less dense plasma remains at the top.
Describe the general structure and functions of leukocytes. State the definitions of diapedesis and leukocytosis.
Leukocytes protect against disease. They slip out of the blood stream by diapedesis. Average is 4-11,000 per mm3 of blood. Leukocytosis is an elevated WBC count. It is normal in response to infection.
Describe the following leukocyte disorders: leucopenia, leukemia (acute and chronic), and infectious mononucleosis.
Leukopenia is an abnormally low WBC count. It can be caused by drugs. Leukemia is a group of cancers. It can be myelocytic or lymphocytic depending on what type of WBC they effect. Deriving from blast-type cells is faster and worse. Bloodstream is full of cancerous WBCs. Mono is a highly contagious, viral disease caused by the Epstein-Barr virus. It causes excessive agranulocytes. There is no cure, it runs its course.
Define leukopoiesis and describe how this process is controlled and what factors are involved. Identify the common progenitor cell for all formed elements in the blood.
Leukopoiessi is the production of WBCs, stimulated by hormones and glycoproteins called cytokines. Cytokines are either interleukins or colony-stimulating factors. Myeloid stem cells produce (NEBM) and lymphoid stem cells produce (L). They all arise from hemocytoblasts.
Describe the 2 general types of agranulocytes, include in your description the functions of each type. Contrast the functions of T and B lymphocytes. Define plasma ell and macrophage.
Lymphocytes have a large nucleus, and function in immunity (in lymphoid tissues). T lymphocytes act directly against cells (cell-mediated) while B lymphocytes give rise to plasma cells and produce antibodies. Monocytes have a kidney shaped nucleus. They differentiate into macrophages that phagocytize viruses and bacteria.
Describe the 3 types of granulocytes; include in your description the functions of each type. Define defenses and histamine.
Neutrophils are the most numerous, and contain hydrolytic enzymes and defensins. They are used to destroy bacteria/fungi on ingestion. They contain 3-6 lobes called PMNs. Eosinophils kill parasites and inactivate inflammatory chemicals. Basophils contain histamine, an inflammatory vasodilator that attracts other WBCs.
Describe Erythrocytes.
Not true cells. Biconcave and anucluate. Bag of hemoglobin. Spectrin gives flexibility to RBC. Made in the red bone marrow.
Define oxyhemoglobin, deoxyhemoglobin, carbaminohemoglboin, hematopoiesis, and erythropoiesis.
Oxyhemoglobin is when oxygen binds to Hb in the lungs. Deoxyhemoglobin is when oxygen detaches from the iron in the tissues. Carbaminohemoglobin is when CO2 in the blood binds to the amino acids of the globin. Blood cell formation is hematopoiesis. RBC production is called erythropoiesis.
Describe the two components of blood. Describe why blood is categorized as a connective tissue.
Plasma (salt-water solution + inorganics and organics) and formed elements. It connects all the parts of the body together; dissolved fibrous proteins become visible during clotting.
Describe how plasma or blood can be appropriately expanded; state what is not an appropriate volume expander.
Plasma can be administered if there is no time to type blood. Plasma expanders (albumin, plasminate, and dextran) increase the fluid volume of blood. Isotonic salt solutions also works since they resemble the electrolyte concentration of plasma. Whole blood transfusions indicated for substantial blood loss and in treating thrombocytopenia, RBCs can be given to treat anemia.
Describe platelets; include in your description the source of these elements, their function, and what regulates their formation.
Platelets are cytoplasmic fragments of megakaryocytic. They form a temporary plug when blood vessels rupture. Thrombopoeitin regulates their formation.
Describe primary and secondary polycythemia and state how these relate to blood doping.
Polycythemia vera is an increase in RBCs due to bone marrow cancer. Secondary polycythemia occurs when less oxygen available or EPO production increases e.g. high altitude living. Blood doping is when athletes increase their oxygen-carrying capacity.
Describe the life cycle of erythrocytes including their fate and destruction. State the life-span of an erythrocyte and where the destruction occurs.
RBCs are unable to grow or divide, so they are only useful for 100-120 days. The spleen is the RBC graveyard. Heme iron salvaged, bound to protein and stored for reuse. Rest is degraded to bilirubin and albumin.
Describe the phases of hemostasis.
See hemostasis drawing assignment.
Describe the structure of an erythrocyte and gives some structure-function relationships of this element.
They are biconcave and flexible. This increase in surface area allows them to pick up more oxygen in lung capillary beds to release to tissues throughout the body. They are over 97% hemoglobin and do not consume transported oxygen.
Define thrombocytopenia, petechiae, and hemophilia.
Thrombocytopenia is a deficiency is the number of circulating platelets. Petechiae forms on the skin. Impaired liver function results from a vitamin K deficiency. Hemophilias are a group of hereditary bleeding disorders that can be treated by injecting the missing factors.
Describe how erythropoiesis is controlled. Include in your description the roles of hypoxia, bone marrow, and EPO. Explain the source of EPO and the mechanism of control.
Too few erythrocytes results in tissue hypoxia. Too many will result in viscous blood. This is regulated by EPO, and also adequate iron, amino acids and certain B vitamins. EPO is produced by the kidney. Iron is bound to transferrin and released to blood from the liver as needed.
Describe Leukocytes.
White blood cells. True cells. Normally 4-11,000 per mm3 of blood. They are defense against disease. Slip out of bloodstream by diapedesis. Made in the bone marrow.