Chapter 29 anatomy and physiology PDF

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Chapter 29: Alterations of Erythrocytes, Platelets, and Hemostatic Function McCance/Huether: Pathophysiology: The Biologic Basis of Disease in Adults and Children, 8th Edition MULTIPLE CHOICE 1. What term is used to describe the capacity of some erythrocytes to vary in size, especially in

relationship to some anemias? a. Poikilocytosis b. Isocytosis c. Anisocytosis d. Microcytosis ANS: C

Anisocytosis means assuming various sizes and is a term used to describe erythrocytes in some anemias. Poikilocytosis is used to describe erythrocytes that can assume various shapes. Isocytosis and microcytosis are not terms that are associated with this condition. PTS: 1

DIF: Cognitive Level: Remembering

2. What is the fundamental physiologic manifestation of anemia? a. Hypotension b. Hyperesthesia c. Hypoxia d. Ischemia ANS: C

The fundamental physiologic manifestation of anemia is a reduced oxygen-carrying capacity of the blood, resulting in tissue hypoxia. Hypotension may result when the initial compensatory mechanism, vasoconstriction, fails to provide adequate perfusion to tissues. Ischemia may result if the oxygen deficit in tissues and organs is severe or prolonged. Hyperesthesia is not a finding. PTS: 1

DIF: Cognitive Level: Remembering

3. The paresthesia that occurs in vitamin B12 deficiency anemia is a result of which of these? a. Reduction in acetylcholine receptors in the postsynaptic nerves b. Myelin degeneration in the spinal cord c. Destruction of myelin in peripheral nerves d. Altered function of neurons in the parietal lobe ANS: B

Effects on the nervous system can occur if a vitamin B12 deficiency causes anemia. Myelin degeneration may occur with the resultant loss of fibers in the spinal cord, producing paresthesia (numbness), gait disturbances, extreme weakness, spasticity, and reflex abnormalities. The paresthesia is not caused by reduction in acetylcholine receptors, destruction of myelin in peripheral nerves, or altered neuronal function in the parietal lobe. PTS: 1

DIF: Cognitive Level: Remembering

4. Which of these describes how the body compensates for anemia? a. Increasing rate and depth of breathing b. Decreasing capillary vasoconstriction c. Hemoglobin holding more firmly onto oxygen d. Kidneys releasing more erythropoietin ANS: A

Tissue hypoxia from anemia creates additional demands and compensatory actions on the pulmonary and hematologic systems. The rate and depth of breathing increase in an attempt to increase the availability of oxygen. The body does not compensate by decreasing vasoconstriction, tightening the hemoglobin bonds with oxygen, or releasing more erythropoietin. PTS: 1

DIF: Cognitive Level: Remembering

5. Which of these classified as a megaloblastic anemia? a. Iron deficiency b. Pernicious c. Sideroblastic d. Hemolytic ANS: B

Megaloblastic anemia is characterized by a low red blood cell count and larger-than-normal red blood cells. Pernicious anemia is the most common type of megaloblastic anemia. Iron deficiency is a hypochromic, microcytic anemia meaning the red blood cells are pale and small. The red blood cells in sideroblastic anemia are not abnormally large; they have an abnormal ring of iron around the nucleus of the RBC. Hemolytic anemia is normochromic, normocytic anemia caused by blood loss. PTS: 1

DIF: Cognitive Level: Remembering

6. The students learn that deficiencies in folate and vitamin B12 alter the synthesis of which of

these? a. RNA b. Cell membrane c. DNA d. Mitochondria ANS: C

Deficiencies in folate and vitamin B12 result in defective erythrocyte precursor DNA synthesis. These deficiencies are not associated with alterations of RNA, cell membranes, or mitochondria. PTS: 1

DIF: Cognitive Level: Remembering

7. A patient has defective secretion of the intrinsic factor leading to anemia. What treatment

option does the healthcare professional discuss with the patient? Increasing iron sources in the diet such as red meat. Vitamin B12 injections initially given once a week. Having relatives tested for bone marrow donation. Better control of the patient’s underlying disorder.

a. b. c. d.

ANS: B

Intrinsic factor (IF) is responsible for B12 uptake from the gut. A lack of IF leads to pernicious anemia, which is treated with vitamin B12 injections for the rest of the person’s life. The injections are weekly at first the monthly. Increasing dietary iron would help with iron-deficiency anemia. A bone marrow transplant might be used to treat aplastic anemia. Better control of an underlying medical condition would be important in anemia of chronic disease. PTS: 1

DIF: Cognitive Level: Applying

8. After a person has a subtotal gastrectomy for chronic gastritis, which type of anemia will

result? a. Iron deficiency b. Aplastic c. Folic acid d. Pernicious ANS: D

A gastrectomy will lead to deficient intrinsic factor which is related to pernicious anemia. The gastrectomy would not lead to iron deficiency, aplastic, or folic acid anemia. PTS: 1

DIF: Cognitive Level: Remembering

9. Which condition resulting from untreated pernicious anemia (PA) is fatal? a. Brain hypoxia b. Liver hypoxia c. Heart failure d. Renal failure ANS: C

Untreated PA is fatal, usually because of heart failure. PTS: 1

DIF: Cognitive Level: Remembering

10. How is the effectiveness of vitamin B12 therapy measured? a. Reticulocyte count b. Serum transferring c. Hemoglobin d. Serum vitamin B12 ANS: A

The effectiveness of cobalamin replacement therapy is determined by a rising reticulocyte count. The other options are not used as indicators of the effectiveness of vitamin B12 therapy PTS: 1

DIF: Cognitive Level: Remembering

11. A healthcare professional has educated a student on folic acid. Which statement by the student

indicates that more teaching is needed? a. Folic acid absorption is dependent on the enzyme folacin. b. Folic acid is stored in the liver. c. Folic acid is essential for RNA and DNA synthesis within erythrocytes. d. Folic acid is absorbed in the upper small intestine.

ANS: A

Folic acid absorption is not dependent on the enzyme folacin. The professional would need to provide more teaching if the student made this statement. The other options are true statements regarding folic acid. PTS: 1

DIF: Cognitive Level: Evaluating

12. Which anemia produces small, pale erythrocytes? a. Folic acid b. Hemolytic c. Iron deficiency d. Pernicious ANS: C

The microcytic-hypochromic anemias, which include iron deficiency anemia (IDA), are characterized by erythrocytes that are abnormally small (microcytic) and contain abnormally reduced amounts of hemoglobin (hypochromic). Folic acid and pernicious anemias are megaloblastic. Hemolytic anemia consists of normal red blood cells that are destroyed more frequently than normal. PTS: 1

DIF: Cognitive Level: Remembering

13. A patient in the healthcare clinic reports fatigue, weakness, and dyspnea, as well as pale

conjunctiva of the eyes and brittle, concave nails. What assessment by the healthcare professional is most appropriate for the suspected anemia? a. Blood pressure and apical pulse b. Oral mucus membranes and tongue c. Ability to swallow foods and liquids d. Skin and sclera for normal coloration ANS: B

Early symptoms of iron deficiency anemia (IDA) include fatigue, weakness, and shortness of breath. Pale earlobes, palms, and conjunctivae are also common signs. Progressive IDA causes more severe alterations, with structural and functional changes apparent in epithelial tissue. The nails become brittle, thin, coarsely ridged, and spoon-shaped or concave (koilonychia) as a result of impaired capillary circulation. The tongue becomes red, sore, and painful. The healthcare professional should assess the patient’s mouth and tongue. Blood pressure and pulse readings would not be specific for any one type of anemia. Dysphagia (difficulty swallowing) could indicate pernicious anemia. Jaundice (most often seen in the sclera and on the skin) would be a characteristic of hemolytic anemia, although it is not always noticed. PTS: 1

DIF: Cognitive Level: Applying

14. A healthcare professional in an urban clinic is seeing a patient who has iron deficiency anemia

(IDA). What question by the professional is most appropriate to assess for the cause of IDA? “How many times a week do you have iron-rich foods?” “Have you ever noticed any blood in your stool?” “Do you have a history of heart valve replacement?” “Have you had any recent viral infections?”

a. b. c. d.

ANS: B

The most common causes of IDA in well-developed countries are pregnancy and chronic blood loss. The healthcare professional would assess for any sources of blood loss. A dietary deficiency of iron may be the cause, but is not common in developed countries. A mechanical heart valve can lead to hemolytic anemia. Recent infections are not associated with iron deficiency anemia. PTS: 1

DIF: Cognitive Level: Applying

15. A healthcare professional works with recent refugees. A mother brings in her children who

have been diagnosed with iron deficiency anemia. What action by the professional is most appropriate? a. Educate the mother on an iron-rich diet. b. Arrange to test for parasitic infections. c. Explain the weekly iron infusions. d. Teach the mother to give iron supplements. ANS: B

Children in developing countries often are affected by chronic parasite infestations that result in intestinal blood and iron loss that outpaces dietary intake. The professional should arrange testing for parasites in the newly arrived children. An iron-rich diet and iron supplements may be appropriate, but unless the cause is addressed, the problem will not be solved by those two actions. Weekly iron infusions are not needed. PTS: 1

DIF: Cognitive Level: Applying

16. A patient has hepatomegaly, bronze-colored skin, and cardiac dysrhythmias. What condition

does the healthcare professional prepare to teach the patient about? a. Aplastic anemia b. Pernicious anemia c. Hereditary hemochromatosis d. Immune thrombocytopenia purpura ANS: C

Hereditary hemochromatosis presents with hepatomegaly, bronze-colored skin, and cardiac dysrhythmias. Aplastic anemia specifically presents with total bone marrow failure. Pernicious anemia can be characterized with neurocognitive dysfunction in addition to the classic signs of all anemias. ITP presents with minor signs of bleeding such as petechiae but soon show major bleeding. PTS: 1

DIF: Cognitive Level: Understanding

17. A healthcare professional is reviewing a patient’s laboratory results and sees that the patient

has a low reticulocyte count and a high iron level. Which type of anemia does the professional associate these findings with? a. Folate deficiency anemia b. Iron deficiency anemia c. Hemolytic anemia d. Anemia of chronic disease ANS: A

These results are characteristic of folate deficiency. Iron deficiency would manifest with normal reticulocyte count and high iron. Hemolytic anemia would show high reticulocyte count and normal or high iron levels. Anemia of chronic disease would have a normal reticulocyte count but low iron levels. PTS: 1

DIF: Cognitive Level: Remembering

18. In aplastic anemia (AA), pancytopenia develops as a result of what? a. Suppression of erythropoietin to produce adequate amounts of erythrocytes b. Suppression of the bone marrow to produce adequate amounts of erythrocytes,

leukocytes, and thrombocytes c. Lack of DNA to form sufficient quantities of erythrocytes, leukocytes, and

thrombocytes d. Lack of stem cells to form sufficient quantities of leukocytes ANS: B

AA is a critical condition characterized by pancytopenia, which is a reduction or absence of all three blood cell types, resulting from the failure or suppression of bone marrow to produce adequate amounts of blood cells. It is not related to lack of DNA. PTS: 1

DIF: Cognitive Level: Remembering

19. A student asks the professor what the most common pathophysiologic process is that triggers

aplastic anemia (AA). What response by the professor is most accurate? a. Autoimmune disease against hematopoiesis by activated cytotoxic T (Tc) cells b. Malignancy of the bone marrow in which unregulated proliferation of erythrocytes

crowd out other blood cells c. Autoimmune disease against hematopoiesis by activated immunoglobulins d. Inherited genetic disorder with recessive X-linked transmission ANS: A

Most cases of AA result from an autoimmune disease directed against hematopoietic stem cells. Tc cells appear to be the main culprits in this process. AA does not include proliferation of erythrocytes. The autoimmune process seems to be mediated by alterations in CD4+, CD8+, and Th-17 T-cell responses and reduced numbers of regulatory T cells. Only a small percentage of patients have an inherited or familial form. PTS: 1

DIF: Cognitive Level: Understanding

20. An allogenic bone marrow transplantation remains the preferred method for treating which

anemia? a. Polycythemia vera b. Aplastic c. Sideroblastic d. Anemia of chronic disease (ACD) ANS: B

Bone marrow and, most recently, peripheral blood stem cell transplantation from a histocompatible sibling are the preferred treatments for the underlying bone marrow failure observed in aplastic anemias. This is not a treatment for polycythemia vera, sideroblastic anemia, or anemia of chronic disease.

PTS: 1

DIF: Cognitive Level: Remembering

21. What does the student learn about warm autoimmune hemolytic anemia? a. Warm autoimmune hemolytic anemia occurs primarily in children. b. It is self-limiting and rarely produces hemolysis. c. Erythrocytes are bound to macrophages and sequestered in the spleen. d. Immunoglobulin M coats erythrocytes and binds them to receptors on monocytes. ANS: C

The immunoglobulin G-coated red blood cells bind to the Fc receptors on monocytes and splenic macrophages and are removed by phagocytosis. This disease occurs mainly in people older than 40 years of age. It is one of the hemolytic anemias and destruction of red blood cells occurs by extravascular processes. The erythrocytes are bound to macrophages, not monocytes. PTS: 1

DIF: Cognitive Level: Remembering

22. A student asks the professor to explain the jaundice that accompanies hemolytic anemia.

Which statement is by the professor is most accurate? a. Erythrocytes are destroyed in the spleen. b. Heme destruction exceeds the liver’s ability to conjugate and excrete bilirubin. c. The patient has elevations in aspartate transaminase (AST) and alanine transaminase (ALT). d. The erythrocytes are coated with an immunoglobulin. ANS: B

Jaundice (icterus) is present when heme destruction exceeds the liver’s ability to conjugate and excrete bilirubin. Jaundice is not as directly related to the destruction of the erythrocytes. It is also not related to liver enzyme elevation or being coated with an immunoglobulin. PTS: 1

DIF: Cognitive Level: Understanding

23. Shortened erythrocyte life span, ineffective bone marrow response to erythropoietin, and

altered iron metabolism describe the pathophysiologic characteristics of which type of anemia? a. Aplastic b. Sideroblastic c. Anemia of chronic disease d. Iron deficiency ANS: C

Anemia of chronic disease specifically results from a combination of (1) decreased erythrocyte life span, (2) suppressed production of erythropoietin, (3) ineffective bone marrow erythroid progenitor response to erythropoietin, and (4) altered iron metabolism and iron sequestration in macrophages. PTS: 1

DIF: Cognitive Level: Remembering

24. A patient has polycythemia vera and presents to the Emergency Department with plethora and

neurological changes. The student asks the healthcare professional to explain the primary cause of these symptoms. What response by the professional is best?

a. b. c. d.

Decreased erythrocyte count Destruction of erythrocytes Increased blood viscosity Tissue destruction by macrophages

ANS: C

As polycythemia vera progresses, many of the symptoms are related to the increased blood cellularity and viscosity. These include plethora, engorgement of the retinal and cerebral veins. Individuals also may experience headache, drowsiness, delirium, mania, psychotic depression, chorea, and visual disturbances. The symptoms of polycythemia vera are not related to decreased erythrocyte counts, destruction of erythrocytes, or tissue destruction by macrophages. PTS: 1

DIF: Cognitive Level: Understanding

25. What does treatment for polycythemia vera involve? a. Therapeutic phlebotomy and radioactive phosphorus b. Restoration of blood volume by plasma expanders c. Administration of cyanocobalamin d. Blood transfusions ANS: A

In low-risk individuals, the recommended therapy is phlebotomy and low-dose aspirin, whereas radioactive phosphorus has been used to suppress erythropoiesis. Plasma expanders, cyanocobalamin, and blood transfusions are not treatments for this disease. PTS: 1

DIF: Cognitive Level: Remembering

26. An adult patient has been hospitalized with thrombocytopenia with a platelet count of

8000/mm3. What action by the healthcare professional is most appropriate? a. Tell the patient not to get out of bed without assistance. b. Prepare the patient for transfusions of whole blood. c. Educate the patient on side effects of heparin. d. Nothing; this finding is normal in an adult. ANS: A

Thrombocytopenia is a platelet count of less than 150,000/mm 3. A platelet count of 8,000/mm3 is low enough to produce spontaneous bleeding, which would be devastating if it occurred in the brain. The healthcare professional should advise the patient not to get out of bed without assistance to help prevent falls. Whole blood is not needed since only platelets are deficient. The patient would not receive heparin as this would increase the chance of bleeding. A normal platelet count in an adult is 150,000 to 350,000/mm 3. PTS: 1

DIF: Cognitive Level: Applying

27. A patient in the hospital has been receiving heparin injections. The platelet count on

admission was 222,000/mm3 and four days later is 113,000/mm3. What action by the healthcare professional is best? a. Prepare to transfuse the patient with platelets. b. Do nothing; this is an expected side effect. c. Switch the heparin to lepirudin

d. Stop all the patient’s medications. ANS: C

After initiating heparin in the hospital this patient’s platelet count dropped by 51%. A drop in more than 50% of the platelet count is seen in more than 95% of patients with heparin-induced thrombocytopenia. The treatment is to withdraw the heparin and use alternatives such as lepirudin. If the platelet count were severely low, transfusion would be indicated. There is no need to stop all the patient’s medications. PTS: 1

DIF: Cognitive Level: Applying

28. A patient is 8 hours postoperative after a long orthopedic procedure. The student asks why

this patient is at particular risk of developing a thromboembolism. What response by the healthcare professional is best? a. Patients tend to have venous stasis from orthopedic operations. b. Anesthetic agents often cause an immune response against clotting factors. c. En...