Erythrocyte Series

Question 1

Progenitor cell from which erythrocytes are derived

Answer 1

CFU-GEMM (aka common myeloid progenitor)

Question 2

Major function of mature erythrocytes

Answer 2

To carry Hb

Question 3

Site of production of erythropoietin

Answer 3

Kidney

Question 4

Stimuli for production of erythropoietin

Answer 4

Tissue hypoxia

Question 5

Mode of action of erythropoietin production when stimulated

Answer 5

Tissue hypoxia → kidney secretes EPO → ↑ plasma EPO → acts upon earliest cell committed to erythroid series to differentiate into rubriblast

• Also promotes early release of reticulocytes into BM
• Also inhibits apoptosis (programmed cell death)

Question 6

First cell identifiable as being in erythrocyte series

Answer 6

Rubriblast

Question 7

Nuclear, chromatin, and cytoplasmic appearance on Wright stain
- Pronormoblast/rubriblast

Answer 7

N: Round to slightly oval
Chromatin: Fine
Cyto: Dark blue

Question 8

Nuclear, chromatin, and cytoplasmic appearance on Wright stain
- Basophilic normoblast/prorubricyte

Answer 8

N: Round to slightly oval
Chromatin: Slightly condensed
Cyto: Dark blue

Question 9

Nuclear, chromatin, and cytoplasmic appearance on Wright stain
- Polychromatic normoblast/rubricyte

Answer 9

N: Round
Chromatin: Quite condensed
Cyto: Gray-blue (hemoglobinization)

Question 10

Nuclear, chromatin, and cytoplasmic appearance on Wright stain
- Orthochromic normoblast/metarubricyte

Answer 10

N: Round
Chromatin: Fully condensed
Cyto: More pink or salmon

Question 11

Nuclear, chromatin, and cytoplasmic appearance on Wright stain
- Polychromatic erythrocyte/reticulocyte (retic)

Answer 11

N: None
Chromatin: None
Cyto: Slightly more blue/purple than mature RBC

Question 12

Nuclear, chromatin, and cytoplasmic appearance on Wright stain
- Erythrocyte

Answer 12

N: None
Chromatin: None
Cyto: Salmon w/ central pallor 1/3 of diameter

Question 13

Maturation stage for when Hb synthesis begins (evident by special methods)

Answer 13

Basophilic normoblast (prorubricyte)

Question 14

Maturation stage for when Hb can be detected by light microscopy

Answer 14

Polychromatic normoblast (rubricyte)

Question 15

Period of time, under normal conditions, that marrow retic remains in BM prior to release in PB

Answer 15

Remains a BM retic for 2 more days, unless an increased need for more RBCs (“stress” or “shift” retic)

Question 16

Period of time, under normal conditions, that blood retics continue to mature in blood after its release from BM

Answer 16

Released in circulation and matures 1 more day before becoming fully hemoglobinized

Question 17

Size (in microns) of normal red cell

Answer 17

6-8 microns

Question 18

Lifespan of normal red cell

Answer 18

120 +/- 10 days

Question 19

Reasons for RBC senescence

Answer 19

• All cells deteriorate overtime due to ↓ activity of many enzymes
• B/c it’s non-nucleated, RBCs are unable to generate new proteins/enzymes
• Depletion of enzymes leads to loss of normal biconcave disc shape → spherical (can’t circulate normally through small splenic cords) → phagocytized by RES

Question 20

Diminished delivery of O2 to tissues, as evidenced by pallor, malaise, and dyspnea; may be caused by blood loss, ↓ RBC production, or ↑ RBC destruction (shortened lifespan)

Answer 20

Anemia

Question 21

Natural cell death characterized by nuclear condensation and loss of cytoplasmic integrity; a mechanism that prevents proliferation of dysplastic or mutated cells

Answer 21

Apoptosis

Question 22

Abnormal increase of basophils in the blood

Answer 22

Basophilia

Question 23

macrophage derived from PB monocyte and is part of RES; 1-2 histiocytes/macrophages which store iron for Hb synthesis

Answer 23

Erythroblastic island (EI)

Question 24

Total mass of RBCs circulating in PB and their BM precursors

Answer 24

Erythron

Question 25

BM process of RBC production

Answer 25

Erythropoiesis

Question 26

Abnormal decrease in Hb content of RBCs so that they appear pale w/ larger central pallor when stained w/ Wright stain

Answer 26

Hypochromia

Question 27

Diminished availability of O2to body tissues, usually secondary to decreased lung capacity or decreased O2-carrying capacity of blood

Answer 27

Hypoxia

Question 28

Productionof erythroid precursor cells that are defective

Answer 28

Ineffective erythropoiesis

Question 29

Conditions involving ineffective erythropoiesis

Answer 29

- Megaloblastic anemia - Thalassemia - Sideroblastic anemia

Question 30

Describes Wright-stained RBC w/ normal color and normal Hb content w/in average cell Hb concentration w/in reference range; MCHC b/w 32-36%)

Answer 30

Normochromic

Question 31

Elevated retic count on PB film stained w/ new methylene blue dye or an increase in number of polychromatophilia

Answer 31

Polychromatophilia (reticulocytosis)

Question 32

Reticulocytosis indicates BM regeneration activity in ____ ____ or ____ ____ ____

Answer 32

Hemolytic anemia; acute blood loss

Question 33

Degradation of a cell where nucleus shrinks in size and chromatin condenses to solid, structureless mass or masses

Answer 33

Pyknosis

Question 34

Aging or growing old; RBC loses its deformability and is cleared by the spleen

Answer 34

Senescence

Question 35

Gray-blue RBC w/ increased diameter; require more than 1 day in PB to lose residual RNA and gain mature-looking reddish cytoplasm

Answer 35

"Shift"/"stress" retic

Question 36

Stain that colors living tissues or cells

Answer 36

Supravital stain