Phys Lab Blood typing

Define gene Defone genetic code Define allele Define Genotype

Gene: is a unit that one organism inherits from a parent organism and is the determining factor of a specific phenotype of an organism. Genetic code: is the sequence of nucleotides in DNA or RNA that determines the specific protein synthesis. Allele: a pair of genes located on a specific site of a specific chromosome. Genotype: the genetic makeup of an organism. Phenotype:the expressionofaspecifictraitinanorganism.

Define agglutinogens(antigens) Define Agglutinins(antibodies) Define Erythrocytes Define Leukocytes Define PLasma

Agglutinogens (antigens): substances found on the surface of erythrocytes. Agglutinins (antibodies): antibodies found in the plasma of blood. Erythrocytes: red blood cells. Leukocytes: white blood cells. Plasma: fluid of the blood where red blood cells are suspended.

Define antisera Define Process of agglutination Define Blood transfusion Define medico-legal Define hemoglobin

Antisera: serum that contains antibodies for one or more antigens. Process of agglutination:the clumping of red blood cells as a result of a reaction to a specific antibody. Blood Transfusion: the transfer of whole blood from one individual to another. Medico-legal: pertains to the legal aspects of the practice of medicine. Hemoglobin: is a protein in the blood, primarily responsible for carrying oxygen from the lungs to the tissues of the body and carbon dioxide from the tissues of the body to the lungs.

be able to name the scientist credited with discovering the four different types of human blood; name the four different types of human blood and the frequencies they appear in the population;

Around 1900, Karl Landsteiner discovered that there are at least four different kinds of human blood, A- 39% B- 12% AB- 4% O- 45% of population

understand the importance of blood typing;

As noted in Figure 1, people can receive transfusions of only certain blood types, depending on the type of blood they have. If incompatible blood types are mixed, erythrocyte destruction, agglutination and other problems can occur. For instance, if a person with type B blood is transfused with blood type A, the recipient's anti-A antibodies will attack the incoming type A erythrocytes. The type A erythrocytes will be agglutinated, and hemoglobin will be released into the plasma. In addition, incoming anti-B antibodies of the type A blood may also attack the type B erythrocytes of the recipient, with similar results. This problem may not be serious, unless a large amount of blood is transfused.

understand the Rh system;

Landsteiner and Wiener reported that rabbit sera containing antibodies for the red blood cells of the Rhesus monkey would agglutinate the red blood cells of 5% of Caucasians. These antigens, six in all, were designated as the Rh (Rhesus) factor, and they were given the letters C, c, D, d, E, and e by Fischer and Race. Of these six antigens, the D factor is found in 85% of Caucasians, 94% of African Americans, and 99% of Asians. An individual who possesses these antigens is designated Rh+; an individual who lacks them is designated Rh-. The genetics of the Rh blood group system is complicated by the fact that more than one antigen can be identified by the presence of a given Rh gene. Initially, the Rh phenotype was thought to be determined by a single pair of alleles. However, there are at least eight alleles for the Rh factor. To simplify matters, consider one allele: Rh+ is dominant over Rh-; therefore, a person with an Rh+/Rh- or Rh+/Rh+ genotype has Rh+ blood. The anti-Rh antibodies of the system are not normally present in the plasma, but anti-Rh antibodies can be produced upon exposure and sensitization to Rh antigens. Sensitization can occur when Rh+ blood is transfused into an Rh- recipient, or when an Rh- mother carries a fetus who is Rh+. In the latter case, some of the fetal Rh antigens may enter the mother's circulation and sensitize her so that she begins to produce anti-Rh antibodies against the fetal antigens. In most cases, sensitization to the Rh antigens takes place toward the end of pregnancy, but because it takes some time to build up the anti-Rh antibodies, the first Rh+ child carried by a previously unsensitized mother is usually unaffected. However, if an Rh- mother, or a mother previously sensitized by a blood transfusion or a previous Rh+ pregnancy, carries an Rh+ fetus, maternal anti-Rh antibodies may enter the fetus' circulation, causing the agglutination and hemolysis of fetal erythrocytes and results in a condition known as erythroblastosis fetalis (hemolytic disease of the newborn). To treat an infant in a severe case, the infant's Rh+ blood is removed and replaced with Rh- blood from an unsensitized donor to reduce the level of anti-Rh antibodies.

Define phenotype Define sensitization Define hemolysis Define erythroblastosis fetalis

Phenotype: the expression of a specific trait in an organism. Sensitization: to make reactive to an antigen. Hemolysis: the destruction of red blood cells and the release of hemoglobin. Erythroblastosis fetalis: is a blood disorder found in human fetuses and infants in which the mother's antibodies attack the developing baby's red blood cells.

name the components and relative abundance of each;

The formed elements in blood include erythrocytes, or red blood cells (RBCs); various types of leukocytes, or white blood cells (WBCs); and platelets. Erythrocytes are circular, biconcave disks of S to 8 micrometers. Their chief function is to transport oxygen (0,) and carbon dioxide (CO,). The transport of 0 2 and CO2 depends largely on the hemoglobin present in the erythrocytes. The biconcave shape is also related to the erythrocytes function of transporting gases, in that it provides an increased surface area through which gases can diffuse. The number of circulating RBCs is closely related to the blood's oxygen-carrying capacity. Any changes in the RBC count may be significant. RBC counts are routinely made to diagnose and evaluate the course of various diseases. Leukocytes range in size from approximately 9 to 25 micrometers and function primarily to control various disease conditions. Leukocytes can move againstthe current of the bloodstream through amoeboid movement, and pass through the blood vessel walls to enter the tissues. The total WBC count normally varies from 5,000 to 10,000/mm3• Certain infectious diseases are accompanied by an increase in WBCs. If the number exceeds 10,000/mm3, the person has an acute infection. If it drops below 5,000/ mm3, the person may have a condition such as measles or chicken pox. The percentage of the different types of leukocytes present in the blood may also change in particular diseases, this number is important for diagnostic purposes and is called a differential count.

understand the genetics of blood typing;

The human blood types (A, B, AB, and 0) are inherited by multiple alleles, which occurs when three or more genes occupy a single locus on a chromosome. Gene IA codes for the synthesis of antigen (agglutinogen) A, gene 18 codes for the production of antigen Bon the red blood cells, and gene i does not produce any antigens. The phenotypes listed in the table below are produced by the combinations of the three different alleles: IA, 18 , and i. When genes 18 and IA are present in an individual, both are fully expressed. Both IA and 18 are dominant over i so the genotype of an individual with blood type O must be ii.

understand the ABO process of agglutination and the lab test performed;

There is a simple test performed with antisera containing high levels of anti-A and anti-B agglutinins to determine blood type. Several drops of each kind of antiserum are added to separate samples of blood. If agglutination (clumping) occurs only in the suspension to which the anti-A serum was added, the blood type is A. If agglutination occurs only in the anti-B mixture, the blood type is B. Agglutination in both samples indicates that the blood type is AB. The absence of agglutination in any sample indicates that the blood type is 0.