Chapter 13 2 - Patho PDF

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NUR 56 Pathophysiology Chapter 13: Disorders of Red Blood Cells 1. What is the main function of Red Blood Cells? -aka erythrocytes or corpuscle, is to deliver oxygen to the body’s tissues 2. What is the major pathophysiologic condition involving red blood cells? -Anemia 3. What is anemia? - a condition in which there is insufficient delivery of oxygen to the tissues because of an inadequate number of mature, healthy RBCs in the blood 4. Insufficient oxygen delivery to the tissues produces what? -produces signs and symptoms related to cellular hypoxia and lack of cell energy 5. What is polycethemia? -less common disorder of RBC’s, characterized by overproliferation of all blood cells in bone marrow 6. What is Erythropoiesis? - the specific series of steps in the bone marrow that leads to the synthesis of mature RBCs 7. What do all RBC’S begin as? - All RBCs begin as a pluripotent stem cell in the bone marrow that is stimulated to become an erythroid precursor cell. - The precursor goes through a series of changes until it becomes a mature erthryocyte released by the bone marrow 8. True or False, RBC has no genetic material in its mature state -True 8a. What is a reticulocyte? -immature RBC 9. What does the last stage of Erythropoiesis involve? When is the nucleus of the RBC is expelled? - involves an immature RBC called a reticulocyte is released from bone marrow when there is rapid bleeding and bone marrow cannot keep up with the need for replacement RBCs - The nucleus of the RBC is expelled in one of the last stages of erythropoiesis, which is why the RBC cannot be used for genetic testing 10. What is a major stimulus for erythropoiesis? What organ senses the stimulus? -Hypoxia is a major stimulus -the kidney senses hypoxia and releases erythropoietin to stimulate bone marrow to synthesize RBC’s 11. What are the steps in Synthesis of Erythropoietin? -1) Low oxygen in blood (hypoxia) is detected by kidney -2) Kidney releases erythropoietin (EPO) which stimulates bone marrow -3) bone marrow then synthesizes RBC’s

12. What are the 4 substances needed for adequate synthesis of healthy RBCs? - protein, iron, vitamin B12, and folic acid 13. what is the main nutritional element needed for hemoglobin synthesis? -Iron 14. What is a hemoglobin composed of? -Heme and Globin compound 15. What is Heme composed of? - Heme is composed of iron (Fe+2) and a protein called porphyrin 16. What is the protein Porphyrin metabolized into? - porphyrin is metabolized into biliverdin, a green-colored compound that colorizes bile, feces, and ecchymoses 17. What is biliverdin broken down to? - Biliverdin is broken down into bilirubin, a yellow-colored compound that is a constituent of bile 18. What is hyperbilirubinemia? - In conditions where there is a high amount of breakdown of RBCs, bilirubin accumulates in the bloodstream, where skin and sclera of the eye stain yellow, resulting in jaundice (also called icterus) 19. What is the number of reticulocytes a good indicator of? What does a high number of reticulocyte count indicate? -a good indicator of bone marrow activity, because it represents recent production of RBCs - A high reticulocyte count indicates that the bone marrow is working hard to keep up with RBC loss. 20. what is the life expectancy of a RBC? What is the function of the spleen? -120 DAYS - spleen removes aged, lysed, and dead RBCs from circulation and in the spleen, RBCs are broken down into their component parts, which are recycled to make new RBCs 21. What is the Spleen? What does it do? When does splenomegaly occur? - the spleen is a highly vascular organ, and is the “graveyard of RBCs” and an organ of immunity - It sequesters abnormally shaped and hemolyzed RBCs and destroys them -Splenomegaly occurs when there is a large amount of RBC breakdown occurring in the body 22. The synthesis of Hemoglobin is greatly dependent on the availability of what element? What does a lack of this element result in? What is normal hemoglobin called? - The synthesis of Hgb is greatly dependent on the availability of iron - A lack of iron results in a lack of Hemoglobin in each RBC and results in low oxygen carriage in the blood - Normal Hgb is called Hemoglobin A. 23. In adults, what is a normal hemoglobin composed of? -composed of 4 polypeptide chains called Alpha 1, Alpha 2, Beta 1 and Beta 2 24. In the fetus until early infancy, there is a specific kind of hemoglobin called what? What does this hemoglobin have and what does it have a high affinity to? - Hemoglobin F

- This Hgb has four alpha chains and a very high affinity for oxygen. It can facilitate transfer of oxygen across the placenta 25. When is Hgb F replaced? - replaced by Hgb A by 6 months of age 26.What are hemoglobinopathies? What is an example of these disorders? -disorders where there is an abnormal structure of Hemoglobin because of a genetic mutation -ex: in sickle cell anemia 27. What occurs in Sickle Cell Anemia? What is there an abnormal substitution of? What different Hgb do people with SCA have? -there is a mutation in one of the genes that direct the synthesis of the Hemoglobin beta polypeptide chains - Within one of the beta chains there is an abnormal substitution of the amino acid valine for glutamic acid. -Because of this mutation, persons with sickle cell anemia have a different Hgb called Hgb S 28. Why is Iron needed? Where is iron mainly absorbed? Where can iron sequester? epithelial intestinal cells are constantly sloughed and excreted, what does this cause? -needed in the diet to synthesize Hgb in RBCs and myoglobin - Iron is mainly absorbed in the duodenum and upper jejunum - Some iron is sequestered within the intestinal cells and some is released into the bloodstream - The epithelial intestinal cells are constantly sloughed and excreted; with loss of the cells, there is loss of iron. 29. When absorbed into the bloodstream from the GI system, iron is transported by what protein? -When absorbed into the bloodstream from the GI system, iron is transported by a protein called transferrin 30. Iron that is bound to transferrin and other proteins is represented by what measurement? -total iron binding capacity (TIBC) 31.Once Iron is carried by transferrin, where does it carry it to? About 10% - 20% of absorbed iron goes into storage as what? - Transferrin carries iron in the bloodstream to the bone marrow for erythropoiesis - About 10% to 20% of absorbed iron goes into storage as ferritin complexes that are present in all cells, but it is most commonly found in the bone marrow, liver, and spleen 32. What is the primary physiological source of reserve iron in the body? -the liver’s store of Ferritin 33. What is the Oxyhemoglobin Dissociation Curve? What does it represent? - The oxy-Hgb dissociation curve is an important tool for understanding how blood carries and releases oxygen. -The oxy-Hgb dissociation curve represents the relationship between PO2 and the affinity of Hgb to oxygen. 34. What occurs when PO2 is 100 mmHg? - When PO2 is 100 mm Hg, hemoglobin is totally saturated with oxygen atoms. This is the ideal and highest level of oxygen-hemoglobin affinity. 35. What occurs when PO2 is 60 mm Hg? - Hgb affinity for oxygen dramatically falls and oxygen is given up to the tissues.

36. Oxygen delivery to tissues is affected by what 2 factors? - both oxy-Hgb saturation and the amount of hemoglobin in the blood. 37. What occurs If the oxygen saturation is 100% and Hgb level is normal? -oxygen delivery to the tissues is ideal. 38. What occurs if oxygen saturation of blood is 100% and Hgb is low (as in anemia)? - oxygen delivery will be inadequate and cellular hypoxia will result. 39. True or False, Hgb has greater affinity for carbon monoxide (CO) compared with oxygen. -True 40. What occurs if there are high levels of CO in the environment? - if there are high levels of CO in the environment, oxygen will be displaced off Hgb sites and saturated with CO - This deoxygenated state is often fatal 41. What are Agglutinogens? What are the 2 different types? - Specific types of antigens on the surface of RBCs - type A and type B 42. What does the ABO Blood Type Classification System categorize? - categorizes blood into four types according to these agglutinogens: type A, B, AB, and O 43. What is another antigen on the surface of RBCs? -another antigen on the surface of RBCs is Rh factor, also called D antigen. -If the RBC surface has the Rh factor, it is categorized as positive (Rh+); if it does not have the Rh factor, it is called negative (Rh-). 44. True or False, All blood types are either Rh+ or Rh-. -True 45. How do Individuals develop antibodies to blood antigens? - Individuals develop antibodies to blood antigens that are not the same as their own 46. A person with type A blood has antibodies against what blood type? -type B blood called anti-B antibodies 47. A person with type B blood has antibodies against what blood type? - type A blood called anti-A antibodies 48. A person with type O blood has no antigens on the surface of their RBCs; but what 2 antibodies do they have? - they have both anti-A and anti-B antibodies 49. A person with type AB blood has what antibodies? -Has NO antibodies 50. Describe Type O negative blood type. - universal donor; there are no antigens on the RBCs that the recipient can react to

51. Describe Type AB positive blood type -Universal recipient - RBCs have both antigens; therefore, they can accept type A or type B blood 52. What occurs if a person receives a different type of blood than their own from a donor? Give an example. - antibodies attack the infused RBCs and cause a transfusion reaction that involves hemolysis - For example, if a person with type A blood receives a type B blood transfusion, the anti-B antibodies of the recipient will attack the type B RBCs of the donor blood 53. What is Anemia? - It can be defined as a decreased RBC mass that becomes clinically apparent when levels of Hgb and hematocrit (Hct) are less than normal - Different types of anemia produce different CBC results 54. How does the World Health Organization define Anemia? -defines anemia as an Hgb level lower than 13 g/dL in men and lower than 12g/dL in women 55. What 7 values does a CBC contain? - Hgb -Hct -Number of RBCs -Reticulocyte count: indicates bone marrow activity -Mean corpuscular volume (MCV): indicates size of the RBC -Mean corpuscular hemoglobin (MCH): indicates color of RBC -Mean corpuscular hemoglobin concentration (MCHC): indicates color of RBC??? 56. Why do women have a lower hemoglobin and hermatocrit levels? - Have lower Hgb and Hct than men because of monthly menstrual blood loss. 57.Why do persons who live in high altitudes normally have high Hgb and Hct? - Persons who live at high altitudes normally have higher Hgb and Hct because their environment naturally has lower oxygen concentration. The low oxygen in their bloodstream constantly stimulates renal erythropoietin which, in turn, stimulates the bone marrow to synthesize RBCs 58. What is a Hematocrit? What are the normal male and female values? - the percentage of blood that consists of RBCs - Male Hct: 45% to 52% -Female Hct: 37% to 48% 59. What is Mean Corpuscular Volume (MCV) and what does this value reflect? What is MCV used to classify? What are the normal values of MCV? -MCV is the volume of one RBC. This value reflects RBC size as seen under the microscope. -It is used to classify the anemia as microcytic, megaloblastic (also called macrocytic), or normocytic. -The normal value of MCV is 80 to 100 femoliters. 60.What are microcytic, megaloblastic (also called macrocytic), and normocytic cells? -Microcytic cells are smaller than normal, megaloblastic cells are larger than normal, and normocytic cells are normal size.

61. What is Mean Corpuscular Hemoglobin (MCH)? What is the normal MCH values? -MCH is the average amount of Hgb in an average RBC. -Normal MCH is 27 to 32 picograms 62. What is Mean Corpuscular Hemoglobin Concentration (MCHC)? What is the normal MCHC range? -MCHC is the average concentration of Hgb in a given volume of RBCs. -The normal MCHC range is 32% to 36%. 63. What can MCH and MCHC used to indicate? What would a low value for either indicate? -MCH and MCHC can be used to indicate the color of the RBCs. -A low value for either indicates that cells are pale or hypochromic 64. What occurs in Normocytic Normochromic Anemia (NCNC)? What causes NCNC? -MCV is normal, MCHC is normal, and size and color of RBCs are normal -Commonly caused by blood loss 65. What occurs in Microcytic Hypochromic Anemia? What mainly causes this? - MCV and MCHC are both decreased, size and color of the RBCs are abnormal. A low MCV indicates small size of RBCs, and a low MCHC indicates pale color of RBCs -Most common cause is Iron deficiency 66. What occurs in Megaloblastic (Macrocytic) Anemia? What are the 2 most common causes of this? -MCV is high, the RBCs are abnormally large; they are also referred to as megaloblastic or macrocytic. - Most common causes: Vitamin B12 deficiency and Folic acid deficiency 67. What are platelets? What can occur if platelets are too low? What can occur if platelets are too high? What are the normal values of platelets in blood? - Platelets are the blood cells that cause clotting of the blood. -If platelets are too low, bleeding or bruising can occur. -If platelets are too high, clotting can occur. -The normal value is 90,000 to 140,000 platelets in the blood. 68. What does a Reticulocyte measure? What are increased reticulocyte numbers associated with? What is the normal percent of Reticulocyte count in total RBCs? -Reticulocyte count measures the number of new RBCs in the blood and helps to determine whether the bone marrow is producing new RBCs at an appropriate rate. -Increased reticulocyte numbers associated with anemia suggest accelerated destruction or loss of RBCs. -Normal reticulocyte count is approximately 1% of total RBCs 69. What are the 10 signs and symptoms of Anemia? - Headache -Dizziness or feeling faint -Weakness -Excessive fatigue -Exercise intolerance -Shortness of breath, especially with activity -Chest pain -Palpitations (tachycardia) -Pallor of skin, conjunctiva, nailbeds, and buccal mucosa

- Nutritional anemias can cause glossitis, cheilitis, koilonychia, or pica 70. What are the 6 ways anemia be diagnosed? - Bone marrow aspiration (biopsy) - Peripheral blood smear which allows microscopic visualization of blood cells - CBC -Echocardiogram -Electrocardiogram (ECG) -Additional diagnostic tests are based on type of anemia (ex. fecal occult blood test, vitamin B12 level, folic acid level) 71. The adult has a total blood volume of approximately ____ liters. The adult can usually lose _____ mL of blood without serious or lasting effects -5 liters; 500 mL 72. What occurs if loss of blood reaches 1,000 mL or more? -serious adverse effects such as hypovolemic shock and cerebral hypoperfusion can occur 73. What causes Anemia of Acute blood loss? - Acute blood loss is a rapid loss of blood as in hemorrhage caused by trauma, childbirth, rupture of a major blood vessel, or organ. Severe gastrointestinal bleeding can occur in disorders such as esophageal varices or penetrating peptic ulcer 74. In terms of the Pathophysiology of Anemia of Acute Blood Loss, what occurs to the cells? What does the lack in sufficient number in RBCs lead to? What may occur if bleeding is severe? -All blood cells and plasma volume are lost which lead to NCNC anemia since cells are normal in size and color but deificient in number -lack of sufficient number of RBCs to carry oxygen causes tissue hypoxia -Reticulocytosis occurs if bleeding is severe 75. In terms of the Pathophysiology of Anemia of Acute Blood Loss, what do bararoceptors detect? Where does fluid shift? - Baroreceptors sense decreased Blood pressure which then stimulate of the sympathetic nervous system to vasoconstrict arteries - Fluid shifts from tissues into the capillaries (cellular dehydration); which stimulates RAAS and release Antidiuretic hormone (ADH) 76. What are 8 symptoms of Acute Blood Loss? -Tachycardia, Tachypnea, Hypotension, Pallor, Oliguria, Thirst, Cool clammy skin and Loss of consciousness 77. what is Hematemesis? -large loss of blood via vomiting, seen in patients bleeding because of esophageal varices 78. What is “Coffee-ground” emesis? - Blood mixed with stomach acid and mucus in vomitus 79. What is melana? - Blood mixed in stool, causing dark, tarry stool,

80. What is hematochezia? - bright red blood in the stool, seen in patients who are losing large amounts of blood via the rectum 81. What occurs in Anemia of Chronic Blood Loss? What are the 4 most common causes? What does Anemia of Chronic Blood Loss lead to? -the patieint is enduring a slow, gradual blood loss -Causes: Peptic ulcer, Inflammatory bowel disease, Colon cancer, and Menorrhagia (excessive monthly menstrual loss) -Leads to IRON DEFICIENCY ANEMIA because the RBCs that are lost are the largest stores of iron in the body 82. How is Anemia of Chronic Blood Loss diagnosed? (5a) - CBC demonstrates Microcytic hypochromic anemia (low MCV and low MCH) -Low Fe++ -Low serum ferritin -High TIBC (total iron binding capacity) -Fecal occult blood test (FOBT) 83. What is the most common cause for iron deficinency in Men? What problems does iron deficiency include? What can present with iron deficiency anemia in both men and women? -loss of blood from the GI tract -Problems include gastritis, ulcerations, esophageal varices, and carcinomas - In both men and postmenopausal women, colon cancer frequently presents with iron deficiency anemia because of undetected chronic blood loss from the GI tract 84. How is Anemia of Chronic Blood Loss treated? (3a) -remdying source of bleeding, Ferrous sulfate, or blood transfusion when Hgb falls below 7g/dL 85. What occurs in Hemolytic Anemia? What are causes of Hemolytic Anemia? What are 8 symptoms of Hemolytic Anemia? How is Hemolytic anemia diagnosed? -accelerated RBC destruction exceeds erythrocyte production -medication side effects, autoimmune disorders, hereditary spherocytosis, blood transfusion reactions, and hemolytic disease of newborn (HDN), prosthetic heart valves, and hemoglobinopathy -Symptoms: Chills, Pallor, Fatigue, Shortness of breath, Tachycardia, Jaundice, Dark urine, Enlarged spleen -Diagnosed: CBC, Peripheral blood smear (that will show spherocytosis, anisocytosis, poikilocytosis), Hgb electrophoresis, Bone marrow biopsy 86. What is Warm Agglutinin Syndrome? - When the antibody causing the destruction of the RBCs is of the IgG class, the hemolysis will occur at any temperature (still leads to hemolytic anemia) 87. What is Cold Agglutinin Syndrome? -When the antibody against the RBCs is of the IgM class, and hemolysis occurs at low temperatures (still leads to hemolytic anemia) 88. What is Sickle Cell Anemia? How can it be inerited in individuals? -common inherited hemoglobinpathies, which is caused by an abnormal kind of Hgb S that distorts the RBCs shape upon exposure to hypoxia or severe stress -individuals can either be heterozygous (where they only carry the trait) or Homozygous (both alleles have mutation and have most severe form of the disease)

89. What causes Sickle Cell Anemia? What does the mutation cause? How SCA transmitted? - The SCA gene mutation causes one of the beta polypeptide chains of Hgb structure to be abnormal as one of the amino acids in the chain, valine, is substituted for glutamic acid. This changes the normal hemoglobin molecule Hgb A into Hgb S, the major type of Hgb in sickle cell anemia - mutation causes structural fragility of the sickle cell anemia RBCs, where upon exposure to hypoxia or stress, the RBC contorts into a sickle shape -Sickle cell anemia is transmitted by a recessive trait. Individuals who are homozygous (have 2 traits for Hgb S) and individuals who are heterozygous (have 1 trait for Hgb S and 1 normal Hgb A) 90. What are Vaso-occlusive crisis? What are the common sites where these episodes occur? -episodes of ischemia caused by sickled RBCs cannot pass through capillaries which become trapped, blocking blood flow and creating ischemia and consequent tissue hypoxia, which leads to organ damage and possible infarction. -Common sites: The chest, abdomen, long bones, and joints 91. What...