Hematology Flashcards
Name the three types of cells that result from lymphopoiesis.
- NK cell
- Plasma (B) cell
- T cell
Name the types of cells that result from the myeloid stem cell:
- Erythrocytes
- Platelets
- Basophils
- Eosinophils
- Neutrophils
- Monocytes/Macrophages
From what does all hematopoietic and lymphopoietic stem cells originate?
The pluripotent stem cells (then myeloid and lymphoid)
Describe the components of blood.
Plasma (55%)
RBCs (45%)
Buffy Coat-WBCs and platelets (<1%)
What is the main function of the RBCs?
Gas transport. Delivery/transport of O2 and getting rid of CO2
Name the two different categories of leukocytes.
Granulocytes and Agranulocytes
Which leukocytes are granulocytes?
Phagocytes: Neutrophils, Eosinophils, Basophils, and Mast cells
Which leukocytes are agranulocytes?
Phagocytes: Monocytes(blood) and macrophages(tissue)
Immunocytes/lymphocytes (T and B): NK cells (granular-atypical)
Describe erythropoiesis.
Pluripotent stem cell is stimulated by erythropoietin which creates a nucleated committed proerythroblast. Next the nucleus shrinks and is reabsorbed creating a normoblast. This then becomes a non-nucleated reticulocyte which leaves the marrow and enters the blood stream. The cell then becomes an eyrthrocyte and Hb synthesis ceases.
What is the normal reticulocyte count and what is it an indication of? Which type of patient would have a higher reticulocyte count?
Less than 1%. It indicates the effectiveness of erythropoiesis. Anemic or sickle cell patients.
What role do the kidneys play in erythropoiesis?
The peritubular cells of the kidney release EPO which stimulates erythrocyte production. Released in hypoxic state.
What is the breakdown of iron in the body at any given time.
- 67% is bound to heme
- 30% stored bound to ferritin or hemosiderin (mononculear phagocytes or hepatic parenchymal cells)
- 3% lost in the urine/sweat/gut/epithelial cells
Explain the iron cycle.
Iron is released by the liver and transported in the plasma as transferrin. The transferrin binds to receptors on the erythroblast membrane (in bone marrow) and transported to the erythroblast mitochondria binding to heme and forming hemoglobin and released into the blood stream. The iron is removed from the bloodstream by macrophages in the spleen and broken down. It is stored as ferrtin in the tissue or transferred as transferrin to bone marrow to begin process again.
Define anemia.
Decrease in the total number of erythrocytes in the circulating blood or in quality/quantity of Hb
Name three common causes of anemia.
1- Decreased erythrocyte production
2- Increased erythrocyte destruction
3- Acute/chronic blood loss
What are MCV, MCH, and MCHC values?
Mean corpuscular volume (cell size)
Mean corpuscular Hb (Hb amount per cell)
Mean corpuscular Hb concentration (Hb amount relative to cell size)
Macrocytic Normochromic anemias include(2):
Megaloblastic Anemia and Pernicious Anemia
Describe Megaloblastic Anemia
A macrocytic normochromic anemia. Unusually large stem cells. Defective DNA synthesis d/t deficiencies in B12 and folate.
Describe Pernicious Anemia
A macrocytic normochromic anemia. Lack of IF from gastric parietal cells=unable to absorb B12 which is necessary for nuclear maturation and DNA synthesis.
What roles do Vit B12 and folate play in Hb synthesis?
Vit B12 aids in DNA synthesis and maturation of RBCs. Folate aids in DNA/RNA synthesis and cell maturation.
Normocytic Normochromic Anemias include(4):
Sickle Cell Anemia
Hemolytic Anemia
Aplastic Anemia
Anemia of Chronic Disease