NR507 ADVANCED QUESTIONS AND ANSWERS

NR507 ADVANCED QUESTIONS AND ANSWERS The site of blood cell formation hematopoiesis varies with age - CORRECT ANSWER-- fetus - yolk sac beginning 3rd week gestation; shift to fetal liver & spleen by week 8 and to bone marrow by 5 month -birth to 5 years red marrow of all bones make blood cells -after 20 years red marrow primarily located in ilium, vertebrae, cranium and jaw, sternum and ribs, humerous and femur. Hematopoiesis occurs throughout life and is stimulated by - CORRECT ANSWERinfiltration of the yellow or fatty bone marrow with red bone marrow cells. faster proliferation and differentiation of stem and daughter cells. Hematopoietic stem cells are - CORRECT ANSWER--are progenitors (apart of) of all hematological cells. -proliferate and differentiate under the control of numerous growth factors and cytokinis to form the three types of cells found in peripheral blood: RBCs, WBCs, and platelets Erythropoiesis - CORRECT ANSWER-formation of red blood cells: -The growth factor erythropoietin is made by the kidney and to a very small extent in the liver in response to tissue hypoxia -is also stimulated by androgens (testosterones) -Normal red blood cell level is between 4.2 to 6.2 million cells per cubic millimeter (approximately 45% of blood volume) -able to replenish 1% of circulating red blood cell mass every 24 hours, which is equivalent to 2.5 million red blood cell synthesized per second. The mature RBC structure - CORRECT ANSWER-biconcave spherical disk for maximum surface area for gas exchange reversible deformability to squeeze through capillaries lacks a nucleus, ribosome, mitochondria ( Without these structures, red blood cells cannot divide or do protein synthesis and can only perform anaerobic metabolism, lifespan in circulation is approximately 100-120 days (But in that time frame, it will have traveled thousands of miles to our vascular system) Red blood cells are essentially a sack of hemoglobin. - CORRECT ANSWER-It is estimated that there are approximately 300 million hemoglobin molecules per red blood cell. Hemoglobin makes up 90% of the dry weight of the cell. males 16 females 14 Hemoglobin has a unique chemical composition that includes polypeptide chains, heme molecules, and iron. iron - CORRECT ANSWER--The primary dietary sources for iron are meats, especially red meat, dry beans, and eggs. -absorbed through the GI track and combines with the plasma protein transferrin (the transporter for iron)→ transport to the liver for storage as ferritin then when needed is released from the liver via transferrin →bone marrow →Iron enters the erythroblasts and is transported directly into the mitochondria. females 19-50 need 18 mg/day females ˃ 50 and males ˂ 19 needs 8mg fe/day Vitamin B12 (Cyanocobalamin) - CORRECT ANSWER-Primary sources are meat, fish, poultry, and dairy is required for DNA, RNA and myelin synthesis (Rna synthesis occurs in its absence, but abnormally large cells form) stomach secrete intrinsic factor protein to facilitate absorption of vitamin from the ilium. Any excess B12 - CORRECT ANSWER-is stored in the liver. Typically, we have a 1000 fold excess reserve, so it can take years to deplete our stores of this vitamin. Folic Acid (Folate) - CORRECT ANSWER-primary dietary sources are liver grains and green vegetable is required for DNA and RNA synthesis and is also important for neural development in utero. absorbed directly from the GI tract in any excess is stored in the liver and depleted in 2 to 3 months red blood cells (erythrocytes) - CORRECT ANSWER-normal recycling occurs as metabolic processes decrease. As blood circulates into spleen, narrow splenic capillaries literally fragmented and old splenic microphages digests RBCs Anemia - CORRECT ANSWER-is a hematological disorder characterized by a reduction in the total number of circulating red blood cells and or a decrease in hemoglobin content or function. is caused by: impaired red blood cell production, excessive blood loss, increased red blood cell destruction, or any combination of the above. reduced RBC and hemoglobin causes - CORRECT ANSWER-causes a decrease in oxygen level (hypoxia, dyspnea, pallor, dizziness and fatigue reduced RBC alone causes a - CORRECT ANSWER-decrease blood volume (Activating the renin, angiotensin, aldosterone system, which promotes fluid retention and movement of interstitial fluid into the capillaries only increase plasma volume, but also dilute the plasma further. The dilute blood flows faster, creating a hyper dynamic state, which stresses the cardiac system. This can progress to tachycardia and even heart failure) Anemias are classified by - CORRECT ANSWER-size: normocytic, microcytic, macrocytic, color: normochromic, hypochromic, hyperchromic (due to hb level) variability: anisocytosis (size), poikilcytosis (shape) normocytic normochromic anemia - CORRECT ANSWER-description: normal cell size and hemoglobin level problem: low cell amount example: Post hemorrhagic anemia, aplastic anaemia, and hemolytic anemia. acute blood loss from the body (severe trauma, surgical, labor delivery complications)