Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PA Biochem > L4: Red blood cell assessment in Anemia > Flashcards

L4: Red blood cell assessment in Anemia Flashcards

(69 cards)

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

What are erythrocytes?

A

Biconcave, disk-like cells with a central pallor and no nucleus, lifespan of ~120 days

Erythrocytes primarily contain hemoglobin for O2 delivery and carry ~70% of the body’s iron.

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

What is the primary function of hemoglobin in erythrocytes?

A

Crucial for O2 delivery

Hemoglobin also plays a role in carrying iron.

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

Where does hematopoiesis occur in healthy individuals?

A

Within the bone marrow

Bone marrow has enormous production capacity and produces about 2 million RBCs per second.

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

How does the production of red blood cells respond to hypoxia?

A

Production can be amplified up to 10 times normal

Hypoxia is sensed by the kidneys, which produce erythropoietin (EPO).

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

In which bones does hematopoiesis occur in children and adults?

A

Children: ALL BONES; Adults: flat bones (cranium, ribs, pelvis, vertebrae)

This difference highlights the change in hematopoietic activity with age.

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

What is erythropoietin (EPO)?

A

A hormone produced by the kidneys in response to hypoxia

EPO stimulates the growth and maturation of erythrocytes.

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

What are hematopoietic stem cells (HSCs)?

A

Cells that give rise to all blood lineages, mostly in a resting state

HSCs are stimulated to proliferate and differentiate by growth factors.

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

What happens to circulating RBCs after their life cycle of approximately 120 days?

A

They are digested by macrophages in the spleen, liver, and bone marrow

Continuous replacement is required through erythropoiesis.

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

What initiates the stimulation of erythropoiesis in the kidneys?

A

Detection of decreased O2 in circulating blood (hypoxia)

This leads to the secretion of erythropoietin (EPO).

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

What is the role of a blast forming unit (BFU) in erythropoiesis?

A

Produces more than 1000 RBC progenitors

These progenitors undergo multiple rounds of cell division before becoming erythrocytes in ~1 week.

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

True or False: Erythropoiesis is a continuous process.

A

True

Continuous replacement of RBCs is essential due to their finite lifespan.

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

Fill in the blank: The kidneys respond to hypoxia by producing _______.

A

erythropoietin (EPO)

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

What happens to immature progenitor cells as they mature?

A

They become smaller in size and the size of the nuclei with respect to cytoplasm decreases. The chromatin in the nucleus becomes coarse and compact.

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

What do mature normoblasts expel to form reticulocytes?

A

They expel their nuclei.

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

What are reticulocytes?

A

Premature enucleated RBCs in the bone marrow.

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

How long do reticulocytes maintain ribosomes and synthesize hemoglobin?

A

For ~4 days, with 3 days spent in the bone marrow and 1 day in blood.

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

What is the typical presence of reticulocytes in circulating blood of healthy adults?

A

They are present at low levels (0.5% - 2.0%).

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

What can cause an increase in reticulocyte production?

A

Blood loss or premature RBC destruction (i.e., hemolytic anemias).

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

What are the normal responses required to EPO?

A
  • Responsive bone marrow
  • At least one healthy kidney
  • Adequate nutrition for hemoglobin synthesis
  • Adequate nutrition for DNA synthesis and cell division.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is anemia?

A

Hemoglobin concentration in whole blood below the reference range.

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

What is the average prevalence of anemia in the U.S.?

A

1 in 77 individuals.

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

Which gender has a higher prevalence of anemia?

A

Females.

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

What factors can affect the prevalence of anemia?

A
  • Different classes of anemia
  • Age
  • Nursing home living
  • Cancer
  • Other clinical conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are common signs and symptoms of anemia?
* Pallor of skin in palms, nail beds, face, or conjunctiva of the eyes * Dizziness * Fatigue
26
Is anemia a disease itself?
No, it is a sign of an underlying disease or condition.
27
What laboratory evaluations can help diagnose common anemias?
RBC indices and calculated lab values.
28
What are the mechanisms of causation for anemia?
* Premature RBC destruction (or blood loss) * Insufficient stimulation of erythropoiesis (kidney damage or insufficient bone marrow mass) * Insufficient RBC production (nutritional deficiencies impacting hemoglobin synthesis or DNA synthesis and cell division)
29
What does CBC stand for?
Complete Blood Count.
30
What does the RBC portion of the CBC provide?
Concentrations for different cellular and noncellular elements of blood measured in cells, volume, or mass per volume.
31
What does RBC concentration measure?
The number of red erythrocytes/RBCs in a given volume of blood ## Footnote Average ~5 x 10^6 cells/μl
32
What is the average hemoglobin concentration in blood?
Approximately 15 g/dL ## Footnote (dL = 100 mL)
33
Define hematocrit (HCT).
The percentage volume of blood that is composed of RBCs ## Footnote Average ~45%
34
What is the 'Rule of 3' used for?
Estimating RBC, HGB, and HCT values in healthy individuals ## Footnote RBC (millions, 10^6) x 3 ≈ HGB (gram %); HGB (gram %) x 3 ≈ HCT (volume %)
35
What does mean corpuscular volume (MCV) represent?
The average volume of RBCs ## Footnote Reference range = 80-100 fL/cell
36
What is indicated by an MCV < 80?
Microcytic RBCs
37
What is indicated by an MCV in the range of 80-100?
Normocytic RBCs
38
What does an MCV > 100 indicate?
Macrocytic RBCs
39
What does mean corpuscular hemoglobin (MCH) measure?
The quantity of hemoglobin in the average RBC ## Footnote Reference range = 26-32 pg
40
What does mean corpuscular hemoglobin concentration (MCHC) measure?
The concentration of hemoglobin in the average RBC ## Footnote Reference range = 32 – 36 g/dL
41
What does MCHC < 32 indicate?
Hypochromic RBCs
42
What does MCHC > 32 indicate?
Normochromic RBCs
43
Why is MCHC > reference range not observed?
Hemoglobin is not completely soluble at higher concentrations and cannot be measured accurately
44
What is the typical value for MCHC?
Usually around 33 g/dL ## Footnote Since HGB ≈ 3 x HCT
45
In which condition is MCHC usually low?
Iron deficiency anemia
46
What does the corrected reticulocyte count (CR) account for?
The decreased HCT observed in anemias to evaluate bone marrow reticulocyte production
47
What is the reference range for the corrected reticulocyte count?
0.5 – 2.5%
48
What is the normal response to RBC loss?
EPO stimulation of erythropoiesis and increased production and release of reticulocytes from bone marrow
49
What does an elevated corrected reticulocyte count (CR) indicate?
Premature RBC destruction/loss in response to continued hemolysis or significant blood loss
50
What is the reference range for corrected reticulocyte count (CR)?
0.5-2.5%
51
What causes a normal or low corrected reticulocyte count (CR)?
* Decreased EPO production (impaired kidney function) * Decreased bone marrow mass (insufficient erythropoietic precursors) * Decreased HGB synthesis (iron deficiency) * Decreased cell division (Vitamin B12 and folate deficiency)
52
What does RBC distribution width (RDW) measure?
Variation in cell size or shape compared to the mean (MCV) in a blood sample
53
What is the reference range for RBC distribution width (RDW)?
11.5-14.5%
54
What are the two types of variations indicated by RDW?
* Anisocytosis (size variation) * Poikilocytosis (shape variation)
55
In which type of anemia is RDW often elevated?
Anemias resulting from nutritional deficiencies (e.g., folate, Vitamin B12, and Iron deficiencies)
56
What is microcytic anemia associated with?
Decreased hemoglobin synthesis
57
What is required for the synthesis of new hemoglobin?
Iron, primarily obtained from recycling of hemoglobin from old or damaged RBCs
58
How does chronic iron deficiency affect RBCs?
It results in decreased hemoglobin synthesis leading to smaller than normal RBCs (microcytic - low MCV) that are not heavily pigmented (hypochromic – low MCHC)
59
What role does protein concentration play in RBCs?
It can regulate cell size
60
What type of anemia is caused by decreased DNA synthesis and cell division?
Macrocytic anemia ## Footnote Macrocytic anemia is characterized by larger than normal red blood cells due to impaired DNA synthesis.
61
Which vitamins are essential for DNA synthesis in all cells?
Vitamin B12 (cobalamin) and Folic acid (Folate) ## Footnote These vitamins are critical for proper cellular function and maturation.
62
What happens to erythropoietic progenitors in the bone marrow during vitamin deficiency?
Nuclear maturation is retarded due to impaired DNA synthesis, resulting in reduced RBC production ## Footnote This leads to the development of megaloblastic red blood cells.
63
What are the characteristics of RBCs in macrocytic anemia?
Immature, enlarged nuclei and larger than normal size due to increased HGB production ## Footnote This condition is referred to as megaloblastic due to the continued protein synthesis.
64
What is pernicious anemia?
Decreased Vitamin B12 absorption due to intrinsic factor loss ## Footnote This condition leads to significant deficiencies in vitamin B12.
65
List common causes of microcytic anemia.
* Iron deficiency * Thalassemias ## Footnote Iron deficiency can be due to chronic GI blood loss or dietary deficiency, while thalassemias are genetic disorders affecting hemoglobin production.
66
What are common causes of normocytic anemia?
* Anemia of chronic disease * Infection * Inflammation * Malignancy ## Footnote Normocytic anemia is often associated with underlying chronic conditions.
67
What are common causes of macrocytic anemia?
* Vitamin B12 deficiency * Folate deficiency ## Footnote Folate deficiency can be due to inadequate diet, alcoholism, and other factors.
68
Fill in the blank: Macrocytic anemia is characterized by _______ red blood cells.
[larger than normal] ## Footnote This enlargement is due to increased hemoglobin production.
69
True or False: Vitamin B12 and folic acid are not essential for DNA synthesis.
False ## Footnote Both vitamins are crucial for DNA synthesis.

PA Biochem (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions