Chapter 29: Alterations of Erythrocyte Platelet, Hemostatic Function Flashcards
What term is used to describe the capacity of some erythrocytes to vary in size, especially in relationship to some anemias? a. Poikilocytosis c. Anisocytosis b. Isocytosis d. Microcytosis
ANS: C
Additional descriptors of erythrocytes associated with some anemias include anisocytosis
(assuming various sizes) or poikilocytosis (assuming various shapes) (see Figure 28-1).
The remaining terms are not associated with this condition.
PTS: 1 REF: Page 982
What is the fundamental physiologic manifestation of anemia?
a. Hypotension
c. Hypoxia
b. Hyperesthesia
d. Ischemia
ANS: C
The fundamental physiologic manifestation of anemia is a reduced oxygen-carrying
capacity of the blood, resulting in tissue hypoxia.
PTS: 1 REF: Page 982 | Page 985
The paresthesia that occurs in vitamin B12 deficiency anemia is a result of which of the
following?
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 the 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. This selection is the only option that accurately describes the cause of
paresthesia in such anemias.
PTS: 1 REF: Page 985 | Page 987
Which of the following 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 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. This selection is the only option that accurately
describes the compensation mechanism in such anemias.
PTS: 1 REF: Page 985
Which of the following is classified as a megaloblastic anemia?
a. Iron deficiency
c. Sideroblastic
b. Pernicious
d. Hemolytic
ANS: B
Pernicious anemia is the most common type of megaloblastic anemia. The remaining
options are not classified as megaloblastic anemias.
PTS: 1 REF: Pages 987-988
Deficiencies in folate and vitamin B12 alter the synthesis of which of the following?
a. RNA
c. DNA
b. Cell membrane
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 the other options.
PTS: 1 REF: Page 987
The underlying disorder of which anemia is a result of the defective secretion of the
intrinsic factor, which is essential for the absorption of vitamin B12?
a. Microcytic
c. Hypochromic
b. Pernicious
d. Hemolytic
ANS: B
Vitamin B12 deficiency causes pernicious anemia, the most common type of megaloblastic
anemia.
PTS: 1 REF: Pages 987-988
After a person has a subtotal gastrectomy for chronic gastritis, which type of anemia will result? a. Iron deficiency c. Folic acid b. Aplastic d. Pernicious
ANS: D
From the options available, only pernicious anemia is caused by vitamin B12 deficiency,
which is often associated with the end-stage type A chronic atrophic gastritis.
PTS: 1 REF: Page 988
What causes the atrophy of gastric mucosal cells that result in pernicious anemia?
a. Erythrocyte destruction
c. Vitamin B12 malabsorption
b. Folic acid malabsorption d. Poor nutritional intake
ANS: C
Deficiency in intrinsic factor (IF) secretion may be congenital or may result from adult
onset gastric mucosal atrophy and the destruction of parietal cells. In older adults, virtually
all vitamin B12-deficiency anemia is caused by a failure of IF-related absorption. This
selection is the only option that accurately identifies the cause of gastric mucosal cell
atrophy.
PTS: 1 REF: Page 988
Which statement best describes a Schilling test?
a. Administration of radioactive cobalamin and the measurement of its excretion in
the urine to test for vitamin B12 deficiency
b. Measurement of antigen-antibody immune complexes in the blood to test for
hemolytic anemia
c. Measurement of serum ferritin and total iron-binding capacity in the blood to test
for iron deficiency anemia
d. Administration of folate and measurement in 2 hours of its level in a blood sample
to test for folic acid deficiency anemia.
ANS: A
The Schilling test indirectly evaluates vitamin B12 absorption by administering radioactive
B12 and measuring excretion in the urine. This selection is the only option that accurately
describes a Schilling test.
PTS: 1 REF: Page 988
What is the treatment of choice for pernicious anemia (PA)?
a. Cyanocobalamin by oral intake
b. Vitamin B12 by injection
c. Ferrous fumarate by Z-track injection
d. Folate by oral intake
ANS: B
Replacement of vitamin B12 (cobalamin) is the treatment of choice for PA. Initial
injections of vitamin B12 are administered weekly until the deficiency is corrected,
followed by monthly injections for the remainder of the individual’s life. The other options
are not treatments for PA.
PTS: 1 REF: Page 988
Which condition resulting from untreated pernicious anemia (PA) is fatal?
a. Brain hypoxia
c. Heart failure
b. Liver hypoxia
d. Renal failure
ANS: C
Of the options available, untreated PA is fatal, usually because of heart failure.
PTS: 1 REF: Page 989
. How is the effectiveness of vitamin B12 therapy measured?
a. Reticulocyte count
c. Hemoglobin
b. Serum transferring
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
Which statement about folic acid is false?
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 other options are true
statements regarding folic acid.
PTS: 1 REF: Page 989
Which anemia produces small, pale erythrocytes?
a. Folic acid
c. Iron deficiency
b. Hemolytic
d. Pernicious
ANS: C
The microcytic-hypochromic anemias, which include iron deficiency anemia (IDA), are
characterized by erythrocytes that are abnormally small and contain abnormally reduced
amounts of hemoglobin. This description is not true of the other options.
PTS: 1 REF: Pages 989-990