examprepare

IV Summary

In the hematocrit test, my blood cell ratio to total blood volume is 40%. Average of males in the class is 45.5%. Average of females in the class is 41%. I am below average hematocrit ratio.

My blood type is A+. 8 people in the class are type A blood. 4 people are type B. 2 people are type AB and 3 people type O. 15 people in the class has Rh positive. There are only two persons showed Rh negative result.

V Conclusion
Hematocrit: this is the percent of the blood that is red blood cells. It is a ratio. It tells if there are enough red blood cells in your blood. The hematocrit is usually done by placing the blood in a tube and spinning the tube in a centrifuge. This separates the solid parts of the blood from the liquid plasma. When heparinized blood (heparin is an anticoagulant) is centrifuged, the red blood cells become packed at the bottom of the tube, while the plasma is left at the top as a clear liquid. The ratio of the volume of packed red cells to the total blood volume is called the hematocrit. Generally speaking, males have higher red blood cell percentage than females.

All humans can be typed for the ABO blood group. There are four principal types: A, B, AB, and O. There are two antigens and two antibodies that are mostly responsible for the ABO types. The specific combination of these four components determines an individual's type in most cases. People with type A blood will have the A antigen on the surface of their red cells (as shown in the table below). As a result, anti-A antibodies will not be produced by them because they would cause the destruction of their own blood. However, if B type blood is injected into their systems, anti-B antibodies in their plasma will recognize it as alien and burst or agglutinate the introduced red cells in order to cleanse the blood of alien protein.Individuals with type O blood do not produce ABO antigens. Therefore, their blood normally will not be rejected when it is given to others with different ABO types. As a result, type O people are universal donors for transfusions, but they can receive only type O blood themselves. Those who have type AB blood do not make any ABO antibodies. Their blood does not discriminate against any other ABO type. Consequently, they are universal receivers for transfusions, but their blood will be agglutinated when given to people with every other type because they produce both kinds of antigens.

If an individual's blood sample is agglutinated by the anti-A antibody, but not the anti-B antibody, it means that the A antigen is present but not the B antigen. Therefore, the blood type is A.

The Rh system was named after rhesus monkeys, since they were initially used in the research to make the antiserum for typing blood samples. If the antiserum agglutinates one's red cells, the person is Rh+. If it doesn't, the person is Rh-. Despite its actual genetic complexity, the inheritance of this trait usually can be predicted by a simple conceptual model in which there are two alleles, D and d. Individuals who are homozygous dominant (DD) or heterozygous (Dd) are Rh+. Those who are homozygous recessive (dd) are Rh- (i.e., they do not have the key Rh antigens).


1. What are some of the factors that might account for some of the variations seen in the results of different class members?

Different sex shows different hematocrit ratio.

2. How do the values obtained fro erythrocyte count, hematocrit, and hemoglobin concentration relate to the oxygen carry capcity of the blood.

The more erythrocytes in a person's body, the more oxygen capacity that pereson has. The bigger the hematocrit test number, the more percentage of red blood cells presented in the body. More red blood cells have more hemoglobin which can bind and carry oxygen. Thus, if hemoglobin concentration is high, they can carry more oxygen as comparing to a low hemoglobin concentration blood.

3. What are the relative advantage of a red blood cell count as compared to a determination of hematocrit? Disadvantages?

A red blood cell count (RBC) is ordered to check whether the number of red cells in the blood is abnormally high or abnormally low. You can get relative absolute number of the cell to check if there is an abnormal value presented in a patient. In hematocrit, the value is only a percentage which might be precise enough to make a diagnosis.

The disadvantage is that counting cells doesnot tell you much about their quality. The values try to describe the red cell population. If you know the red cell count and you know how much volume these cells take up (Hct), then by dividing the hematocrit by the red cell count will give you the average (or mean) cell volume. Similarly, if you know the total weight of hemoglobin and the red count, then you can find out the average or mean weight of hemoglobin in each cell. And, if you know the weight of hemoglobin and the volume of blood that is red cells, you can determine what percentage of an average red cell is taken up by hemoglobin. The benefit of these indices is that you can quickly narrow down the potential causes of anemia; the disadvantage is that these number assume a similar population of cells.

4. Explain the mechanism which accounts for one blood type being considered as a universal donor.

If you belong to the blood group 0, you have neither A or B antigens on the surface of your red blood cells but you have both A and B antibodies in your blood plasma. That is the reason type 0 is often called universal donor.

5. Propose one or more mechanisms to explain how the new anti-coagulant you are developing works.

Hepain is a biological substance, usually made from pig intestines. It works by activating antithrombin III, which blocks thrombin from clotting blood.

posted by C-T @ 9:24 AM