Red Blood Cells PDF

CCCSON Hematology Red Blood Cells PDF Erythrocytes or _____ red _________ blood _________s cells (RBCs) are the m...

CCCSON Hematology Red Blood Cells PDF Erythrocytes or _____ red _________ blood _________s cells (RBCs) are the main cells in the blood. What are the other two types of cells in the blood? white blood cells and platelets All blood cells are made from blood stem cells (or hematopoietic stem cells – HSCs). These rare but important stem ________ cells are found in the bone ma__________ rrow and are responsible for making RBCs, WBCs ( ___________ white blood cells) and platelets. Figure 1 Blood Cells Made by Hematopoietc Stem Cell Red blood cells ( R __ __ B __s C ) are produced from stem _________s cell in the ________ bone marrow. Their main function is to carry o__________ xygen to all body tissues. Figure 2 Hemoglobin Carries Oxygen 1/6  When the cells aren’t getting enough oxygen, the kidneys increase production of erythropoietin. This ery ______________ thropoietin signals the stem ________ cells in the bone m__________ arrow to produce more R __ __ B C__s. Remember! The body NEEDS a certain number of red blood cells to keep the body tissues well- oxygenated. IF there is a sudden, LARGE loss of RBCs, the kidneys (which take hours – days to respond to decreased oxygenation) will not have enough time to replace the lost blood cells. Plus, it takes about 7 DAYS for an RBC to mature. If a client is hemorrhaging, the body will activate its emergency systems (like the SNS (_______________ sympathetic ____________ nervous _______________), system also know as the body’s “fight or f_________ light response. The SNS will try to compensate for the loss of blood cells (and plasma) by sending epinephrine to the β1 receptors in the heart. This stimulation will ↑ ↓ decrease the heart rate. The SNS will work to dilate constrict the peripheral blood vessels to send more of the blood that’s left in the circulation to the vital organs and try to RAISE the ____/____. B P As you can see in the diagram below, if the blood loss is more gradual and happens over several days or even weeks, then the kidneys will send more ery_______________ thropoietin to the bone marrow and make more RBCs to replace the ones that were lost. Figure 2 The Body Responds to Loss of Red Blood Cells (Sudden or Gradual) The number of red blood cells in a sample of blood is called the Red Blood Cell count (or RBC). A machine takes a small sample of the blood and counts the number of RBCs, WBCs and platelets (they are different sizes and that’s how the machine tells them apart). A normal RBC would be 4.7 – 6.1 for males and 4.2 – 5.4 for women. That means that in each cubic millimeter (mm3) of blood, there are about 5,000,000 RBCs. 2/6  Hemoglobin is the part of the RBC that carries oxygen. Each red blood cell contains about 270 million molecules of hemoglobin. The Hemoglobin (Hgb.) lab test measures the weight of hemoglobin molecules in a sample of blood. The hemoglobin in the RBC contains the “heme” (or iron) which is the heaviest part of the cell. Normal hemoglobin (H g__ __.) b for males is 14 – 18 grams/dL (deciliter), and for females 12 – 16. It is a complicated test – the hematocrit is much easier to perform. Hemoglobin makes up about ⅓ of the total cell volume of the RBC – so the hemoglobin count is usually about ⅓ the hematocrit. This means that the hematocrit is usually 3 times the hemoglobin. A client has a hemoglobin of 15. What would you expect the hematocrit to be? 45 When a sample of blood is put in a centrifuge, the different parts of the blood separate out by weight – and the heavier red cells settle to the bottom of the tube. In the picture (left), erythro_________ cytes or RBCs make up about 45% of the blood volume (with about 1% WBCs and most of the rest plasma). This 45% is called the Hematocrit (Hct). The h _______________ ematocrit measures the percentage of red blood cells in the total blood volume. Normal values vary – for adult females, 37 – 47% of the blood volume will be R__ B__ C__s. For males the hematocrit is usually higher – 42 – 52%. F __________ emales usually have less RBCs than males. So hematocrit measures the # of RBCs by volume. The hemoglobin measures the amount of hemoglobin (the _____________-carrying oxygen part of the RBC) by weight. Red __________ blood _________s cells are made up of two parts – heme and globin. The heme part of hemoglobin contains iron that binds with oxygen to form oxyhemoglobin. (Note – Some hemoglobin molecules bind to glucose in the blood. They are called Hemoglobin A1C or glycosolated hemoglobin and are increased with poor diabetic control.) Hemoglobin gives the RBCs their _______ red color. If red cells do not have enough hemoglobin, they may be pale or hypochromic cells. Hypochromic cells are commonly seen in iron deficiency anemia (remember iron is the part of the hemo____________ globin molecule that gives the red cells their color. Hyperchromic cells are rarely seen. There are a few other lab tests done for red blood cells. The Mean Corpuscular Hemoglobin (MCH), Mean Corpuscular Volume (MCV) and the Mean Corpuscular Hemoglobin Concentration are all calculated from the RBC, Hgb. and Hct. The Mean Corpuscular Hemoglobin ( M __ __ C __ H ) measures the 3/6 weight of hemoglobin in an average RBC. Normal M__ C __ H __ for adults is 26-34 picograms (pg). (A picogram is 1 trillionth of a gram). The MCH is calculated by dividing the Hgb by the RBC and multiplying X10: 𝐻𝐻𝐻𝐻𝐻𝐻. MCH = 𝑥𝑥10 𝑅𝑅𝑅𝑅𝑅𝑅 Let’s look at a sample MCH. Suppose the Hgb is 12 and the RBC is 4.2: 12 MCH = 𝑥𝑥10 = 28.6 pg 4.2 Remember! One test by itself doesn’t tell you that much. The tests have to be looked at together – and then they give you a better picture of how the client is doing. The MCH above shows normal amount of hemoglobin in the average RBC. The MCV – Mean Corpuscular Volume – shows the average red cell volume in a sample of blood. It is calculated by dividing the Hct by the RBC and multiplying X10 (sound familiar?). Hct. MCV = × 10 RBC If we look at the MCH example above, what should the Hct be (approximately)? 36 MCV = × 10 = 85.7 𝑓𝑓𝑓𝑓 (The normal range for MCV is 80 – 95 fL.) 4.2 The MCHC is the Mean Corpuscular Hemoglobin Concentration. The M __ C __ H __ C __ shows the amount of hemoglobin in each red blood cell compared with cell size. Normal values for adults are 31- 38%. The MCHC is calculated by dividing the Hgb by the Hct and multiplying X 100: Hgb MCHC = × 100 Hct 𝟏𝟏𝟏𝟏 For our example above: × 100 = 33.3 𝑔𝑔/𝑑𝑑𝑑𝑑 𝟑𝟑𝟑𝟑 And the RDW – Red Cell Distribution Width – shows the difference in sizes between the smallest erythrocyte in a sample and the largest. 4/6  In the sample above, most of the RBCs are about the _________ normal size. The average cell volume is usually about 90 femtoliters (a femtoliter is 1 quadrillionth of a liter). One looks much smaller than the rest (microcytic), and one looks bigger (macrocytic). The RDW would measure the percentage difference in sizes between the larger cell and the smaller cell. This patient would have a high RDW. What would their MCV be? Probably about normal – because most of the cells are normal size – and the big cell would balance out the small cell! These tests help doctors (and nurses!) find out what kind of anemia, or other blood problem, a patient has. For example, iron-deficiency anemia is a microcytic, hypochromic anemia (low MCH and low MCV) with a decreased number of red blood cells. Red __________ blood ________s cells live for about 120 days in the circulation. They must remain very flexible to squeeze through the tiny capillaries where oxygen is released to the tissues, and carbon dioxide is picked up. When red blood cells circulate through the spleen it filters out damaged cells. These damaged red cells are broken down in the liver and bilirubin is produced and excreted in the bile. What happens if the liver is damaged (say with cirrhosis) and bilirubin builds up in the blood stream? Liver damage (e.g., cirrhosis) causes bilirubin buildup, leading to jaundice, dark urine, and other symptoms These are the basic tests you should know for RBCs. There are many others – like the cell morphology tests which look for diseases like sickle cell anemia. Each test by itself doesn’t tell us too much. We have to look at them together, with the rest of the client’s labs and compare them to the client’s condition. We will look at a common condition, anemia, in the next worksheet. Questions 1. Where does oxygen bond in the red blood cell? a. Plasma b. Hemoglobin c. Nucleus d. Cell membrane 2. About 45% of a “normal” blood sample is RBCs. This is called the: a. Hemoglobin b. RDW (red cell distribution width) c. MCH (mean corpuscular hemoglobin) d. Hematocrit 5/6 3. The average volume of a single erythrocyte is called the: a. Mean corpuscular volume b. Mean corpuscular hemoglobin c. Red cell distribution width d. RBC (red blood cell count) 4. Red blood cells live for about _______ days. a. 30 b. 50 c. 90 d. 120 5. Which organ is responsible for stimulating the production of RBCs? a. Bone marrow b. Kidneys c. Spleen d. Liver 6. RBCs are made in the: a. Bone marrow b. Liver c. Kidneys d. Liver 7. A nurse in long term care is reviewing a resident’s labs. The labs show an RBC of 3.4 with a Hgb. of 10.4 and a Hct. Of 31.6. These labs show: a. Chronic anemia b. Acute anemia c. Severe anemia d. Need to know baseline labs to better evaluate for any significant changes 8. In #7 above, what would the client’s MCH be? 30.6 pg 6/6