1. Hematocrit is what measures the red blood cells in blood. Red blood cells are important for transporting iron and oxygen and for creating energy. If the red blood cell count is lower-than-normal it could indicate several diseases and problems within the body. It may be due to anemia, bleeding, destruction of red blood cells, leukemia, malnutrition, low iron, folate, vitamin B12 and vitamin B6 or overhydration. A bacterial infection causes white blood cells to increase, since they are the cells that attack and destroy the bacteria. As the white blood cells increase, red blood cells decrease.
2. All formed elements begin in red bone marrow as pluripotent stem cells. Pluri means several and these type of stem cells have the ability to turn into many different types of cells. For formed elements pluripotent cells reproduce in the bone marrow and become two different types of cells: myeloid stem cells and lymphoid stem cells. While myeloid stem cells complete development in the red bone marrow and create the majority of formed elements in the blood, lymphoid stem cells finish up in the lymphatic tissues of the body. From there lymphocytes are created and all formed elements, including lymphocytes, are swept into the blood stream to complete their jobs. However, lymphocytes divide once they leave the marrow, while other formed elements do not.
3. Erythropoiesis is the creation of red blood cells. The making of red blood cells (RBCs) starts in the red blood marrow with another cell called a proerythroblast. The proerythroblast is basically an immature red blood cell. As they mature they then become a reticulocyte. A reticulocyte is the middle, or “teenage,” stage of a RBC. One it fully matures it becomes an erythrocyte. The rate of RBC production is regulated by the percentage of reticulocytes versus RBC circulating. Erythropoiesis is controlled directly by the amount of oxygen carried to the kidneys. If the kidneys are not receiving enough oxygen to distribute to the rest of the body, it will release a hormone into the blood stream called erythropoietin, which signals the bone marrow to create more proerythroblasts.
4. If a person with type B blood were given type O blood in a transfusion, there would be no negative impact. Blood types are determined by antigens, or proteins on the surface of the blood cells. A person with type B blood has the antigen B, while a person with type O blood does not have any antigens present. Thus the term “universal donor.” With the antigens, we also carry antibodies, called agglutinins, which react negatively with the A or B antigen. Blood type B contains the anti-A antibody. Since the type O blood does not carry either antigen, the agglutinin has nothing to attack if it was introduced into the body.
5. A. This WBC is a lymphocyte and its function is to fight viral infections and some leukemias. B. This WBC is a basophil and its function is to fight allergic reactions, leukemias, cancers and indicate hypothyroidism. C. This WBC is a monocyte and its function is to fight viral or fungal infections, tuberculosis, some leukemias and other chronic diseases. D. This WBC is a neutrophil and its function is to fight bacterial infections, burns, stress and inflammation. E. This WBC is an eosinophil and is function is to fight allergic reactions, parasitic infections and autoimmune diseases.
6. A person with a parasitic disease would have a higher level of leukocytes because they are the cells that combat the parasite. Leukocytes are white blood cells, which are used to fight a variety of infections. Eosinophils are specific to parasitic infections and they attack the parasite by releasing enzymes that destroy the invader. The count would be higher because they are battling the parasite and do not return to the blood stream once they leave. This is a normal reaction if there is an invader in the body.
7. Lymphocytes are responsible for the immune response against pathogens. Lymphocytes are continuously moving through the lymphoid tissues, lymph and blood. They only spend a few hours at a time in the blood and act as a first defense system. They are very effective in destroying bacteria and making their toxins inactive.
8. Prothrombinase is an enzyme that converts prothrombin, a plasma protein that is formed in the liver, into the enzyme thrombin. Thrombin then converts soluble fibrinogen, which is another liver protein, into insoluble fibrin. Fibrin is what forms the threads of the blood clot to stop bleeding. The main difference between the extrinsic and intrinsic pathways are that the extrinsic pathway occurs outside of the blood vessels while intrinsic occurs within the vessels. The extrinsic pathway occurs rapidly, with clotting occurring in seconds, while intrinsic takes several minutes and is more complex than the extrinsic pathway.