Ch. 18: Red Blood Cell Morphology and Approach to Diagnosis Flashcards

1
Q

What type of cells perform the vital physiologic function of oxygen delivery to the tissues?

A

Red Blood Cells (RBCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What component within the erythrocyte can bind to oxygen in the lungs and then release it appropriately in the tissues?

A

Hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

From what Greek word was anemia derived from?

A

Anaimia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define anaimia.

A

Without blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Dec. in RBCs, or the amount of hemoglobin in the RBCs, results in (increased/decreased) oxygen delivery.

A

Decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The decrease of _____ can lead to tissue hypoxia.

A

Dec. in RBCs, or the amount of hemoglobin in the RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give the functional definition of anemia.

A

It is a decrease in the oxygen carrying capacity of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give the operational definition of anemia.

A

It is a reduction, from the baseline value,
in the total number of RBCs
in the amount of circulatiing hemoglobin
in RBC mass of a particular patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain why in practice, the operational definition is not applicable.

A

A patient’s baseline value is rarely known

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give the conventional definition of anemia.

A

It is a decrease in RBCs, hemoglobin, and hematocrit below the reference range for healthy individuals of the same age, sex, and race, under similar environmental conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Enumerate problems that may occur with the conventional definition.

A

Definition of normal is different for each of the data sets
(Different reference ranges)
Pools of individuals lack heterogeneity required to be universally applied to all the different populations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the classic symptoms associated with anemia?

A

Fatigue

Shortness of breath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Iron deficiency can lead to a symptom called _____, wherein a patient can have cravings for unusual substances such as ice (pagophagia), cornstarch, or clay.

A

Pica

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Patients experiencing a rapid fall in hemoglobin concentration typically have _____.

A

Tachycardia (Fast heart rate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the hemoglobin concentration of a patient with moderate anemia?

A

7 - 10 g/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the hemoglobin concentration of a patient with sever anemia?

A

less than 7 g/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The severity of the anemia is gauged by the _____, _____, and the _____

A

Degree of reduction in RBC mass
Cardiopulmonary adaptation
Rapidity of progression of anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Reduced delivery of oxygen to tissues caused by reduced hemoglobin causes an (increase/decrease) in erythropoietin secretion by the kidneys.

A

Increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What secretes erythropoietin when there is reduced delivery of oxygen to tissues?

A

Kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

This stimulates the RBC precursors in the bone marrow, which leads to the release of more RBCs into the circuation.

A

Erythropoietin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

With persistent anemia, what physiologic adaptations are done to increase the oxygen-carrying capacity of a reduced amount of hemoglobin.

A

Increase in:
Heart rate
Respiratory rate
Cardiac output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

This condition triggers an increase in RBC 2, 3-bisphosphoglycerate that shifts the oxygen dissociation curve to the right (decreased oxygen affinity of hemoglobin) and results in increased delivery of oxygen to tissues

A

Tissue hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The increase in _____ shifts the oxygen dissociation curve to the right (decreased oxygen affinity of hemoglobin) and results in increased delivery of oxygen to tissues

A

RBC 2, 3-bisphosphoglycerate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the lifespan of the RBC in circulation?

A

120 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In a healthy individual with no anemia, how many percent of the RBCs are removed from corculation due to senescence?

A

1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

This releases reticulocytes that mature into RBCs in the peripheral blood circulation.

A

Bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Adequate RBC production requires several nutritional factors, such as _____.

A

Iron
Vitamin B12
Folate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

At what conditions should the bone marrow increase RBC production to compensate for the increased RBC loss?

A

Excessive bleeding

Hemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

This is the term used for marrow erythroid proliferative activity.

A

Erythropoiesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Normal erythropoiesis occurs in the _____.

A

Bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

This refers to the production of erythroid progenitor cells that are defective.

A

Ineffective erythropoiesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The defective progenitor cells produced during ineffective erythropoiesis are often destroyed in the _____ and released into the _____.

A

Bone marrow

Peripheral circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What conditions are characterized by ineffective erythropoiesis?

A

Megaloblastic anemia
Thalassemia
Sideroblastic anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

In anemias characterized by ineffective erythropoiesis, the peripheral blood hemoglobin is (high/low) despite an increase in RBC precursors in the bone marrow

A

Low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

In ineffective erythropoiesis, the effective production rate is considerably (greater/less) than the total production rate, which results in a (increased/decreased) number of normal circulating RBCs.

A

Less

Decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

This refers to a decrease in the number of erythroid precursors in the bone marrow.

A

Insufficient erythropoiesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Insufficient erythropoiesis results in the following conditions:

A

Decreased RBC production

Anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What factors can lead to decreased RBC production?

A

Deficiency of iron
(Inadequate intake, malabsorption, excessive loss from chronic bleeding)
Deficiency of erythropoietin
Loss of erythroid precursors due to an autoimmune reaction
(Aplastic anemia, acquired pure red cell aplasia)
Infection
(Parvovirus B19)
Suppression of the erythroid precursors due to infiltration of the bone marrow with granulomas (sarcoidosis) or malignant cells (acute leukemia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

This is the hormone that stimulates erythroid precursor proliferation and maturation.

A

Erythropoietin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Enumerate intrinsic causes of hemolysis.

A

Intrinsic defects in:
RBC membrane
Enzyme systems
Hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Enumerate extrinsic causes of hemolysis.

A

Antibody-mediated processes
Mechanical fragmentation
Infection-related destruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What test must be performed to detect the presence of anemia?

A

Complete blood count (CBC)

43
Q

What values are determined in the complete blood count (CBC)?

A
RBC count
Hemoglobin concentration
Hematocrit
RBC indices
White blood cell (WBC) count
Platelet count
44
Q

Among the RBC indices included in the complete blood count (CBC), what is the most important?

A

Mean cell volume

45
Q

This is a measure of the average RBC volume in femtoliters (fL)

A

Mean cell volume (MCV)

46
Q

What machine is used to perform the complete blood count (CBC)?

A

Automated hematology analyzer

47
Q

Aside from being used for the complete blood count (CBC), this medical laboratory machine can also provide an RBC histogram and the red blood cell distribution width.

A

Automated hematology analyzer

48
Q

This is an RBC volume frequency distribution curve with the relative number of cells plotted on the ordinate and RBC volume in femtoliters on the abscissa.

A

RBC histogram

49
Q

On an RBC histogram, where is the relative number of cells plotted?

A

Ordinate

50
Q

On an RBC histogram, where is the RBC volume in femtoliters plotted?

A

Abscissa

51
Q

On an RBC histogram, what is the term used to describe the distribution of a normal population of cells?

A

Gaussian

52
Q

On an RBC histogram, a left shift in the curve due to an abnormality would indicate _____.

A

Microcytosis

53
Q

On an RBC histogram, a right shift in the curve due to an abnormality would indicate _____.

A

Macrocytosis

54
Q

On an RBC histogram, what can cause a widening of the curve?

A

A greater variation of RBC volume about the mean

The presence of two populations of RBCs with different volumes (Anisocytosis).

55
Q

This is the coefficient of variation of RBC volume expressed as a percentage.

A

RBC distribution width (RDW)

56
Q

This RBC indice indicates the variation in RBC volume within the population measured and correlates with anisocytosis on the peripheral blood film.

A

RBC distribution width (RDW

57
Q

The _____ count serves as an important tool to assess the bone marrow’s ability to increase RBC production in response to an anemia.

A

Reticulocyte

58
Q

These are young RBCs that lack a nucleus but still contain residual ribonucleic acid (RNA).

A

Reticulocytes

59
Q

How many days will a normal reticulocyte circulate peripherally while completing their development?

A

1 day

60
Q

What is the adult reference range for the reticulocyte count which is expressed as a percentage of the total number of RBCs?

A

0.5% - 1.5%

61
Q

What is the newborn reference range for the reticulocyte count?

A

1.5% - 5.8%

62
Q

How is an absolute reticulocyte count determined?

A

Percent reticulocytes X RBC count

63
Q

Based on a normal adult RBC count, what is the reference range for the absolute reticulocyte count?

A

25 - 75 x 10^9/L

64
Q

The reticulocyte count may be corrected for anemia by multiplying the reticulocyte percentage by the patients _____ and dividing the results by 45 (average normal hematocrit). [(Reticulocytes% x Px ___)/45]

A

Hematocrit (Hct)

65
Q

This is a component in the evaluation of an anemia that serves as a quality control to verify the results produced by automated analyzers.

A

Peripheral blood smear

66
Q

What is the diameter of normal RBCs on a Wright-stained blood film?

A

6 - 8 um

67
Q

What is the diameter of microcytic RBCs on a Wright-stained blood film?

A

<6 um

68
Q

What is the diameter of macrocytic RBCs on a Wright-stained blood film?

A

> 8 um

69
Q

Enumerate some shape abnormalities that can only be observed by studying the RBCs on a peripheral blood smear.

A

Spherocytes
Sickle cells
Schistocytes
Macrocytes

70
Q

Enumerate some RBC inclusions that can only be observed by studying the RBCs on a peripheral blood smear.

A

Malarial parasites
Basophilic stipplin
Howell-Jolly bodies

71
Q

This is indicated for a patient with an unexplained anemia associated with or without other cytopenias, fever of unknown origin, or suspected hematologic malignancy. This evaluates hematopoiesis and can determine if thereis abnormal infiltration of the marrow.

A

Bone marrow examination

72
Q

Enumerate some findings in the marrow that can point to an underlying cause of an anemia.

A

Abnormal cellularity of the marrow
Evidence of ineffective erythropoiesis
Megaloblastic canges
Lack of iron on iron stains on bone marrow
Presence of granuloma, fibrosis, infectious agents, and tumor cells that may be inhibiting normal erythropoiesis

73
Q

What other tests performed on the bone marrow can assist in the diagnosis of anemia?

A

Flow cytometry
Cytogenetic studies
Molecular studies to detect abnormal cells, specific gene mutations, and chromosome abnormalities

74
Q

What other tests can assist in establishing the cause of anemia?

A
Routine urinalysis (To detect hemoglobinuria or an increase in urobilinogen) with a microscopic examination (to detect hematuria or hemosiderin)
Analysis of stool (to detect occult blood or intestinal parasites)
75
Q

The absolute reticulocyte count is useful in initially classifying anemias into the categories of decreased RBC production ([increased/decreased] reticulocyte count) and shortened RBC survival ([increased/decreased] reticulocyte count).

A

Decreased

Increased

76
Q

When the reticulocyte count is decreased, the mean cell volume (MCV) can further classify the anemia into three subgroups: _____, _____, and _____.

A

Normocytic anemia
Microcytic anemia
Macrocytic anemia

77
Q

This is characterized by an MCV of less than 80 fL with small RBCs (<6 um in diameter)

A

Microcytic anemia

78
Q

(Normocytic/Microcytic/Macrocytic) anemia can be accompanied by hypochromia and increased central pallor in the RBCs.

A

Microcytic

79
Q

This is characterized by an MCHC of less than 32 g/dL

A

Hypochromatia

80
Q

(Normocytic/Microcytic/Macrocytic) anemias are caused by conditions that result in reduced hemoglobin synthesis: iron deficiency, inability to utilize iron, globin synthesis effects (Thalassemia), and heme synthesis defects (Sideroblastic anemia, lead poisoning).

A

Microcytic

81
Q

This is characterized by an MCV of greater than 100 fL with large RBCs (>8 um in diameter).

A

Macrocytic

82
Q

Give the two types of macrocytic anemia.

A

Megaloblastic

Nonmegaloblastic

83
Q

This type of macrocytic anemia is caused by conditions that impair synthesis of deoxyribonucleic acid (DNA), such as vitamin B12 and folate deficiency or myelodysplasia.

A

Megaloblastic

84
Q

This type of macrocytic anemia is characterized by oval macrocytes and hypersegmented neutrophils in the peripheral blood and by megaloblasts or large nucleated RBC precursors in the bone marrow. MCV can increase to 150 fL

A

Megaloblastic

85
Q

This form of macrocytic anemia is also characterized by large cells and they are typically related to membrane changes owing to disruption of the cholesterol-to-phospholipid ratio. Rare for MCV to increase beyond 115 fL

A

Nonmegaloblastic

86
Q

This type of anemia is characterized by an MCV in the range of 80 - 100 fL.

A

Normocytic anemia

87
Q

Some normocytic anemias develop due to premature destruction and shortened suvival of RBCs (hemolytic anemias), characterized by a/an (elevated/decreased) reticulocyte count.

A

Elevated

88
Q

Some normocytic anemias develop due to decreased production of RBCs, characterized by a/an (elevated/decreased) reticulocyte count.

A

Decreased

89
Q

This can help determine the cause of an anemia when used in conjunction with the mean cell volume (MCV).

A

RBC distribution width (RDW)

90
Q

The RDW can subclassify the three MCV categories as _____ or _____.

A

Homogenous (normal RDW)

Heterogenous (Low/High RDW)

91
Q

An investigation of this type of anemia is required in cases of an elevated reticulocyte count caused by the shortened survival of RBCs.

A

Hemolytic

92
Q

This test can help differentiate immune-mediated destruction from the other causes of hemolytic anemia.

A

Direct antiglobulin test

93
Q

In this type of classification of anemia, related conditions are grouped by the mechanism causing the anemia.

A

Pathophysiologic classification

94
Q

In this type of classification of anemia, the anemias caused by increased RBC destruction or loss (intrinsic and extrinsic abnormalities of RBCs) are distinguished from anemias caused by decreased RBC production (disorders of DNA synthesis).

A

Pathophysiologic classification

95
Q

What are the common clinical signs and symptoms of anemia?

A

Fatigue

Shortness of breath

96
Q

This is the RBC index used to describe the average RBC volume

A

MCV

97
Q

Variation in RBC volume is expressed by the _____.

A

RDW

98
Q

An increase in _____ suggests a reduced RBC lifespan and a hemolytic anemia.

A

Reticulocyte

99
Q

Give examples of an anemia causing low MCV and normal RDW.

A

Heterozygous thalassemia
Anemia of chronic inflammation
Hb E disease/trait

100
Q

Give examples of an anemia causing low MCV and high RDW.

A

Iron deficiency

Sickle cell-B(beta)-thalassemia

101
Q

Give examples of an anemia causing normal MCV and normal RDW.

A

Anemia of chronic inflammation
Anemia of renal disease
Acute hemorrhage
Hereditary spherocytosis

102
Q

Give examples of an anemia causing normal MCV and high RDW.

A

Early iron, folate, or vitamin B12 deficiency
Mixed deificiency of iron + vitamin B12 or folate
Sickle cell anemia
Hb SC disease

103
Q

Give examples of an anemia causing high MCV and normal RDW.

A

Aplastic anemia
Chronic liver disease
Alcoholism

104
Q

Give examples of an anemia causing high MCV and high RDW.

A
Folate or Vitamin B12 deficiency
Myelodysplastic syndrome
Chemoterapy
COld agglutinin disease
Chronic liver disease