UAMS Hematology Final Exam 1

What is hematology? - Correct Ans-The study of blood cell formation, destruction, maturation, and number of blood cells which can vary with disease or infection. What is the most common specimen of hematology? - Correct Ans-Blood, that may be clotted or anticoagulated with EDTA, heparin, or sodium citrate. What are the types of normal blood cells? - Correct Ans-RBCs or erythrocytes, platelets or thrombocytes (PLT), WBCs or leukocytes, monocytes, lymphocytes, and granulocytes which include banded or segmented neutrophils, basophils, and eosinophils. What is CBC and what does it count? - Correct Ans-Complete blood count. RBCs, WBCs, platelets, hemoglobin, and hematocrit. What does MCV stand for? MCH? MCHC? What causes MCH and MCHC to be increased or decreased? - Correct Ans-Mean cell volume measures the size of RBCs. Mean cell hemoglobin measures the weight of hemoglobin in RBCs. Mean cell hemoglobin content measures the average concentration of hemoglobin within RBCs. MCH and MCHC are increased with macrocytic anemia and decreased with microcytic anemia. What is white cell differential? (diff) - Correct Ans-It categorizes cells in a 100-cell differential based on their maturity levels, to determine if a disease or infection is present. What are the organs of the RES and what is their function? - Correct Ans-Spleen, liver, thymus, lymph nodes, and bone marrow. The RES is a network of cells within these tissues that help with the formation and destruction of RBCs to fight infection and prevent bleeding, the metabolism of iron to give to RBCs to carry oxygen through hemaglobin, inflammation, and immunity. What is one of the largest organs in the body and where is it found? Is the site of active bone marrow always the same? - Correct Ans-Bone marrow, found within the cavities of cortical bones where the trabecular bone is also found. In utero and at birth, most bones contain red bone marrow. At age 7, sites of bone marrow begin to decrease and are restricted to proximal long bones, vertebrate, skull, sternum, ribs, and pelvis. Adults have 50:50 ratio of red to yellow bone marrow. What are the types of bone marrow? What is the composition of red bone marrow? - Correct Ans-There are two types of bone marrow. Red that is actively producing RBCs, and yellow that is inactive, mainly composed of fat cells. Red bone marrow is composed of extravascular cords that contain all blood cell lineages, stem cells, progenitor cells, adventitial cells, and macrophages. The cords are semi liquid and wedged between sinuses, supported by trabeculae. How does red bone marrow receive blood supply? - Correct Ans-Periosteal arteries that wrap around the central vein supply blood. The periosteal arteries branch out to form capillaries and sinuses which hook up to larger veins to return the blood to circulation. How are cells released from the bone marrow? What are measures the body can take if RBCs aren't able to be supplied fast enough? - Correct Ans-The cells are released as the body needs them. RBCs are kept at a steady rate. Adventitial cells forming a discontinous line along the sinus will retract allowing the RBCs to exit into circulation. If needed, the yellow bone marrow can convert into red marrow to help make RBCs. What do the lymph nodes encapsulate? What do these do? - Correct Ans-Lymphocytes, plasma cells, and macrophages. They play a role in producing new lymphocytes, interacting with antigens and making antibodies, and ridding the blood of bacteria and debris. What is the largest lymphoid organ? What does it do? - Correct Ans-Spleen, it functions to act as a filter for blood to remove old or deformed RBCs from circulation. These RBCs will either be culled (destroyed entirely) or pitted (macrophages bite out damaged section). The spleen can also become a site of RBC production if needed and is also a holding cell for platelets. What is the composition of the spleen? - Correct Ans-It has a red outer pulp and an inner white pulp. Blood passes through the red pulp first that has macrophage lined cords that determine if RBCs need to be removed or not. The blood then enters the inner white pulp where the sinuses are to re-enter circulation. In what cases would a spleen removal be necessary? How would this change the components of the blood? - Correct Ans-A spleen might be removed to treat some cases of anemia. The blood would be seen to have a higher RBC count, but some of them would be deformed or damaged. The blood would also be seen to have a higher platelet count. What is hematopoiesis? - Correct Ans-The production of blood cells. Initially begins in the spleen and liver but ends up in the bone marrow by the 12th week of gestation and will be the only site by birth. Where do cells produced during hematopoiesis end up? - Correct Ans-Most cells end up in the peripheral blood but some will stay behind in the bone marrow. What is a pluripotent stem cell? In cancer patients, why are these extremely important? - Correct Ans-It is what cell production starts with. A cell that can become anything depending on the stimulus received. It is capable of self renewal and will give rise to a differentiated progeny such as a myeloid or lymphoid multipotent stem cell. Pluripotent stem cells can replenish the hematopoietic system after radiation has been done. After a pluripotent stem cell has received a stimulus and became a multipotent stem cell, what happens? - Correct Ans-A multipotent stem cell will receive a growth factor such as interleukins or cytokines and commit to one cell line. Either myeloid or lymphoid (level 1). What is the sequence of hematopoiesis? - Correct Ans-A pluripotent stem cell will receive a stimulus to become a multipotent stem cell. The multipotent stem cell will commit to only one line, either a myeloid or lymphoid progenitor cell depending on growth factors received. The progenitor cells become granulocyte blasts that replicate and proliferate. Eventually, proliferation ceases as cells mature and enter the peripheral blood. Some cells with further differentiate in the tissues. What are the growth factors received by the multipotent cell? - Correct Ans-CFU, CSF, and erythropoietin produced in the kidney in response to blood-oxygen tension. What are the levels of hematopoiesis? - Correct Ans-Level 1 - multipotent stem cells capable of self renewal found in the bone marrow. Level 2 - progenitor cells capable of limited self renewal found in the bone marrow. Level 3 - precursor cells capable of only differentiation found in the bone marrow. Level 4 - mature blood cells capable of some differentiation found in the peripheral blood. Level 5 - tissue cells capable of some differentiation found in the tissues. What is the lifespan of a WBC? - Correct Ans-A pluripotent cell becomes a multipotent cell which commits to a myeloid cell line and becomes a progenitor cell. The progenitor cell becomes a WBC precursor cell and differentiates. Maturation occurs in the bone marrow. The mature cells stay in the marrow for several days and then diapadese into peripheral blood and into the tissues where they live for about 1-2 days. They do not return to the blood or marrow. They are then removed by RES. What is the development of WBCs? What are the typical growth factors? - Correct Ans-Leukopoiesis. Interleukins. What are general cell maturation features? - Correct Ans-A decrease in size, nucleus condensation, and loss of basophilia. Myeloid cells have granules in their cytoplasm. What are the different types of granules and how do they appear stained? - Correct Ans-Primary granules appear first, usually as promyelocytes. Secondary granules appear as myelocytes and increase in number as the cell matures. Other secondary granules