Deck 5: The Erythrocyte

Question 1

The life span of a normal erythrocyte is about:

A) 9-11 days
B) 5-7 days
C) 120 days
D) 6 hours

Answer 1

120 days

Question 2

Increased hemoglobin affinity for oxygen correlates to which of the following?

A) An elevated 2,3-BPG
B) A normal 2,3-BPG
C) A decreased 2,3-BPG
D) This cannot be determined.

Answer 2

A decreased 2,3-BPG

Question 3

Of the following, who would have the highest concentration of erythropoietin?

A) A child
B) A patient who has just donated a kidney
C) An anemic patient
D) A pregnant mother

Answer 3

An anemic patient

Question 4

In a nonanemic adult, what is the normal range for peripheral blood reticulocytes?

A) 0.5-1.0%
B) 0.1-1.0%
C) 2.0-4.0%
D) 0.5-2.0%

Question 5

What analyte can help to differentiate between intravascular and extravascular hemolysis?

A) Hemoglobin
B) Bilirubin
C) Haptoglobin
D) Reticulocytes

Question 6

The average RBC is what size?

A) 20-25 mcM
B) 2-3 mcM
C) 12-15 mcM
D) 7-8 mcM

Question 7

Red blood cell production begins with what cell?

A) Progenitor
B) Hematopoietic stem cell
C) CFU
D) BFU

Question 8

Which part of the RBC membrane is essential for transporting proteins and anions across the membrane?

A) Lipids
B) Integral proteins
C) Peripheral proteins
D) Skeletal proteins

Question 9

All of the following proteins interact with spectrin in the RBC membrane except:

A) Glycophorin A
B) Ankyrin
C) Band 4.1
D) Actin

Question 10

A reticulocyte count is 6%. This result is:

A) Normal
B) Increased
C) Decreased
D) Erroneous

Question 11

A blood sample has an elevated bilirubin, low haptoglobin, and low hemopexin. What is the most likely reason for this?

A) Increased extravascular hemolysis
B) Hypersplenism
C) Ineffective erythropoiesis
D) Increased intravascular hemolysis

Question 12

Choose the correct order of normoblastic maturation from least mature to most mature.

A) Erythrocyte, reticulocyte, polychromatophilic normoblast, orthochromatic normoblast, basophilic normoblast, pronormoblast
B) Pronormoblast, basophilic normoblast, polychromatophilic normoblast, orthochromatic normoblast, reticulocyte, erythrocyte
C) Basophilic normoblast, pronormoblast, polychromatophilic normoblast, orthochromatic normoblast, erythrocyte
D) Pronormoblast, polychromatophilic normoblast, orthochromatic normoblast, reticulocyte, erythrocyte

Question 13

Expansion of the inner leaflet of the erythrocyte membrane lipid bilayer by the influx of sodium and water results in the formation of:

A) Echinocytes
B) Stomatocytes
C) Spherocytes
D) Dacrocytes

Question 14

Where does normal extravascular hemolysis take place?

A) Blood vessels and bone marrow
B) Lymph nodes and spleen
C) Spleen and liver
D) Bone marrow and liver

Question 15

Which component of the erythrocyte membrane is primarily responsible for the zeta potential of the red blood cell?

A) Phospholipids
B) Glycolipids
C) Spectrin
D) Integral proteins

Question 16

Polychromatophilic erythrocytes are representative of what cell type?

A) Normoblast
B) Prorubricyte
C) Reticulocyte
D) Metarubricyte

Question 17

Which of the following best correlates with an increased reticulocyte count?

A) An increased bilirubin
B) The presence of schistocytes in the peripheral blood smear
C) Increased polychromasia on the peripheral blood smear
D) Anisocytosis and poikilocytosis

Question 18

The deformability of the RBC membrane is attributed to which of the following?

A) Peripheral proteins
B) Integral proteins
C) Sodium potassium pump
D) Glycophorins

Question 19

What is the primary mechanism by which erythropoietin affects RBC production?

A) It expedites the maturation time of RBCs.
B) It prevents premature apoptosis of RBCs.
C) It stimulates facilitated incorporation of hemoglobin into RBCs.
D) It stimulates expulsion of nuclei from nucleated erythrocyte precursors at a quicker rate.

Question 20

Energy metabolism of the erythrocyte is achieved primarily through which of the following?

A) Aerobic glycolysis
B) Anaerobic glycolysis
C) Asexual replication
D) Mitosis

Question 21

Which pathway produces the energy required for proper RBC function from ~90% of the consumed glucose?

A) Methemoglobin reductase
B) Hexose monophosphate shunt
C) Glycolytic
D) Rapoport-Leubering shunt

Question 22

What contributes to the RBC cell's membrane integrity?

A) Skeletal proteins
B) Glycolytic pathway
C) 2,3-BPG
D) Methemoglobin reductase

Question 23

Which metabolic pathway protects hemoglobin from oxidation via NADH?

A) Rapoport-Luebering shunt
B) Embden Meyerhof pathway
C) Hexose monophosphate shunt
D) Methemoglobin reductase pathway

Question 24

Explain the effect of the following on RBC survival.
a. An absence of G6PD
b. An absence of PK
c. A defect in spectrin
d. A defect in ankyrin

Question 25

Predict the results of erythropoietin in a patient with hypoxia.

A) It will be increased.
B) It will be normal.
C) It will be decreased.
D) This cannot be determined.

Question 26

Match the following characteristics with the appropriate stage of maturing erythrocytes:
a. Erythrocyte
b. Pronormoblast
c. Polychromatophilic normoblast
d. Reticulocyte
e. Basophilic normoblast
f. Orthochromic normoblast
________ Earliest morphologically recognizable erythrocytic cell
________ First visible appearance of hemoglobin
________ Stage when the nucleus becomes pyknotic and is extruded
________ First stage without a nucleus
________ First stage without ribosomes
________ Last stage capable of mitosis

Question 27

Describe the nuclear and cytoplasmic morphologic changes in erythrocytes during maturation.

Question 28

What element or property contributes to the normal shape of the RBC?

A) Sodium
B) Spectrin tetramer
C) Calcium
D) Magnesium

Question 29

Explain how the body catabolizes hemoglobin in both extravascular and intravascular hemolysis.

Question 30

Which of the following "marks" the RBC as senescent?

A) A cluster of band 3 proteins on the RBC membrane
B) An RBC with denatured hemoglobin on the RBC membrane
C) An elongated RBC
D) Hyperphosphorylation of integral proteins

Question 31

Explain how EPO regulates RBC production.

Question 32

The production of 2,3-BPG occurs in which erythrocytic metabolic pathway?

A) Embden-Meyerhof pathway
B) Hexose monophosphate shunt
C) Rapoport-Luebering shunt
D) All of the above

Question 33

What growth factor influences the production of the erythrocyte?

A) Transforming growth factor-β
B) Interferon-γ
C) Erythropoietin
D) CFU-E

Question 34

What effect would a deficiency in G6PD have on RBC survival?

A) It would increase the survival of the RBCs.
B) It would decrease the survival of the RBCs.
C) It would have no effect on the survival of the RBCs.
D) This cannot be determined.

Question 35

What protein is the major membrane attachment point of the latticework that laminates the inner lining of the RBC membrane?

A) Tropomodulin
B) Troponyosin
C) Ankyrin
D) Band 3

Question 36

Which major integral protein is used in the mechanism to transport the chloride-bicarbonate exchange?

A) Glucose transporter
B) Anion exchange protein
C) Ankyrin
D) Adducing

Question 37

Which of the following molecules is a senescence signal when it is exposed on the outer leaflet of the erythrocyte?

A) Band 3
B) Ankyrin
C) Phosphatidylethanolamine (PE)
D) Phosphatidylserine (PS)