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Hematology 1 (old) > Module 1: Normal Blood Components, Production, and Erythrocytes > Flashcards

Module 1: Normal Blood Components, Production, and Erythrocytes Flashcards

1
Q

What is hematopoiesis?

A

The production and development of blood cells, characterized by the constant restoring of the various cells of the blood

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2
Q

Name the parts of the hematopoietic system

A

bone marrow, liver, spleen, thymus, and lymph nodes

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3
Q

What does erythropoiesis produce?

A

Erythrocytes (red blood cells)

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4
Q

What does leukopoiesis produce?

A

Leukocytes (white blood cells)

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5
Q

What does thrombopoiesis produce?

A

Thrombocytes (platelets)

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6
Q

Name the 5 type of luekocytes

A

Granulocytes (have visible granules):

  • neutophils
  • eosinophils
  • basophils
  • monocytes
  • lymphocytes (t cells and b cells)
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7
Q

What is a myeloid cell? What blood cells are myeloid cells?

A

Myloid cells are produced and differentiate in the bone marrow (red only). The cells are erthyrocytes, platelets, neutrophils, eosinophils, basophils, and monocytes. *everything except lymphocytes!

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8
Q

What is a non-myeloid cell? What blood cell is the only non-myeloid cell?

A

Non-myeloid cells are produced and differentiate outside of the bone marrow. Lymphocytes are the only non-myeloid cells.

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9
Q

Define medullary hematopoiests

A

The production of blood cells (myeloid cells) in the bone marrow

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10
Q

Define extra-meduallry hematopoiesis

A

The production of myeloid cells outside the bone marrow. Usually in the spleen and/or liver. *This is not normal in adults

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11
Q

When does blood cell production start in the human body?

A

At about 2 weeks gestation

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12
Q

What happens in the mesoblastic phase of hematopoiesis? How long does it last?

A

Occurs during the 2nd to 12th week of gestation. During this time the yolk sac and embryo produce primitive blood stem cells, called erythroblasts.

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13
Q

When do blood vessels and the heart start circulation blood in the human body?

A

By the end of the 4th week of gestation, which is during the mesoblastic phase

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14
Q

What happens in the hepatic phase of hematopoiesis? How long does it last?

A

Occurs during the 6th week of gestation to around two weeks after birth. The liver and spleen produce more mature erythrocytes: first granulocytes, then monocytes. The lymph nodes produce lymphocytes. The bones and bone marrow begin forming at the 8th week of gestation.

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15
Q

What happens in the myeloid phase of hematopoiesis? How long does it last?

A

Occurs from the 20th week of gestation until death. Lymph nodes continue producing lymphocytes. All other blood cells, myeloid cells, are produced by the red bone marrow. The liver and spleen still have the potential for hematopoiesis if necessary.

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16
Q

What is red bone marrow?

A

Active bone marrow that produces blood cells

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17
Q

What is yellow bone marrow?

A

Inactive bone marrow that is mostly fat. Very little hematopoiesis occurs.

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18
Q

Where is red bone marrow located in adults?

A
  • The anterior and posterior iliac crests of the pelvis (hip bones)
  • Sternum
  • Proximal ends of the long bones
  • Vertebrae
  • Skull
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19
Q

Where are non-myeloid cells produced?

A

Lymph nodes and other lymphatic tissue such as the liver, spleen, and tonsils

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20
Q

What connective cell tissues are found in the bone marrow?

A

Fibroblasts (collagen, elastin, reticular protein), endothelial cells, blood cells, blood vessels, and nerves

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21
Q

What is the growth environment of the bone marrow sometimes called?

A

Hematopoietic Inductive Microenvironment (HIM)

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22
Q

When does the liver become involved with hematopoiesis?

A

The 2nd trimester. It becomes the principle site of cell production

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23
Q

What does the spleen do during the myeloid stage of hematopoiesis?

A

It is involved in the removal of old and damaged red cells and storing platelets. It is also the largest lymphoid organ

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24
Q

What does the thymus do in hematopoiesis?

A

It is involved with the production and maturation of T-lymphocytes (T-cells)

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25
Q

What do lymph nodes do in hematopoiesis?

A

They are involved with the formation of new lymphocytes

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26
Q

What are stem cells?

A

Primitive, formative, unspecialized blood cells. They have the potential to change into several types of more specialized offspring

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27
Q

What is the first, most primitive stem cell associated with hematopoiesis?

A

The reticulum cell

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28
Q

What does the reticulum cell specialize into?

A

The CFU-S (Colony forming unit -stem)

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29
Q

Describe the CFU-S (Colony forming unit - stem)

A

They are also known as pluripotential blood stem cells and multipotent lymphohematopoietic stem cells. They are partially differentiated.

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30
Q

What can a CFU-S (Colony forming unit - stem) differentiate into?

A

Either a CFU-L (colony forming unti - lymphoid) or a CFU-GEMM (colony forming unit - granulocyte, erythroid, monocyte, megakaryocyte)

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31
Q

What can a CFU-L (colony forming unit - lymphoid) differentiate into?

A

Various levels of lymphocyte precursors, including T and B lymphoblasts and NK (natural killer) cells

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32
Q

What can a CFU-GEMM (colony forming unit - granulocyte, erythroid, monocyte, megakaryocte) differentiate into?

A
  • CFU-Eo (eosinophil)
  • CFU-baso (basophil)
  • CFU-GM (granulocyte, monocyte)
  • CFU-G (granulocyte)
  • CFU-M (monocyte)
  • BFU-E (burs forming unit - erythroid)
  • CFU-E (erythroid)
  • BFU-meg (burst forming unit - megakaryocyte)
  • CFU-meg (megakaryocyte)
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33
Q

What is a blast cell?

A

The earliest stage of a blood cell that can be visually recognized as the precursor to a particular cell line

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34
Q

Name all the blast cells

A
  • pronormoblast (erythrocyte)
  • megakaryoblast (megakaryocyte/platelet)
  • monoblast (monocyte)
  • myeloblast (neutrophil)
  • lymphoblast (lymphocyte)
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35
Q

What two cells do not have a specific blast phase?

A

Eosinophils and basophils

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36
Q

Would blast cells ever be seen in the peripheral blood?

A

No, unless there was a serious disorder

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37
Q

What are growth factors?

A

Proteins that bind to receptors on cells surfaces, resulting in activation of cellular proliferation/maturation

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38
Q

What are cytokines?

A

The most important growth factors in regards to hematopoiesis. They are chemical mediators that are secreted locally and affect their target cells

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39
Q

Name the growth factors secreted by macrophages, lymphocytes, and bone marrow stromal cells (ie: fibroblasts, endothelial cells)

A

Colony stimulating factors (CSF) and interleukins (IL)

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40
Q

What cells secrete CSF and IL’s?

A

Macrophages, lymphocytes, and bone marrow stromal cells (fibroblasts, endothelial cells)

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41
Q

Name the growth factors that are secreted by the kidneys

A

Erythropoietin (EPO)

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42
Q

What secretes EPO?

A

The kidneys

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43
Q

Name the growth factors secreted by the liver

A

Thrombopoietin (TPO)

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44
Q

What secretes TPO?

A

The liver

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45
Q

What is a monokine?

A

A cytokine produced by macrophages

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46
Q

What is a lymphokine?

A

A cytokine produced by lymphocytes

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47
Q

Outline the phases in the production of erythrocytes

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-GEMM
  4. BFU-E
  5. CFU-E
  6. Pronormoblast
  7. Erythrocyte
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48
Q

Outline the phases in the production of thrombocytes

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-GEMM
  4. BFU-meg
  5. CFU-meg
  6. Megakaryoblast
  7. Thrombocyte
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49
Q

Outline the phases in the production of monocytes

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-GEMM
  4. CFU-GM
  5. CFU-M
  6. Monoblast
  7. Monocyte
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50
Q

Outline the phases in the production of neutrophils

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-GEMM
  4. CFU-GM
  5. CFU-G
  6. Myeloblast
  7. Neutrophil
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51
Q

Outline the phases in the production of euosinophils

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-GEMM
  4. CFU-Eo
  5. Eosinophil
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52
Q

Outline the phases in the production of basophils

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-GEMM
  4. CU-baso
  5. Basophil
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53
Q

Outline the phases in the process of lymphocytes

A
  1. Reticulum cell
  2. CFU-S
  3. CFU-L
  4. Lymphoblast
  5. Lymphocyte (T-cell, B-cell, NK)
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54
Q

What produces tissue necrosis factor and interleukin-1?

A

Monocytes and macrophages

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55
Q

What do tissue necrosis factor and interleukin-1 do?

A

Activate and stimulate cytokin production in lymphocytes and bone marrow stromal cells

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56
Q

What produces stem cell factor, flt ligand, interleukin-3, and interleukin-5?

A

Lymphocytes

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57
Q

What do stem cell factor, flt ligand, and interleukin-3 do together?

A

Induce differentiation and mitosis of CFU-S into CFU-GEMM or CFU-L cells

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58
Q

What does interleukin-5 do?

A

Induces eosinophil growth and function

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59
Q

What produces granulocyte/monocyte stimulating factor, ganulocyte (neutrophil) stimulating factor, and monocyte/macrophage stimulating factor?

A

The bone marrow stromal cells

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60
Q

What does granulocyte/monocyte stimulating factor do?

A

Induces differentiation and mitosis of CFU-GEMM into committed stem cells. Also stimulates phagocytic and cytotoxic functions of neutrophils and macrophages

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61
Q

What does granulocyte (neutrophil) stimulating factor do?

A

Induces maturation and mitosis of CFU-G and myeloblasts

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62
Q

What does monocyte/macrophage stimulating factor do?

A

Induces maturation and mitosis of CFU-M and monoblast cells

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63
Q

What produces erythropoietin?

A

Kidney cells

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64
Q

What does erythropoietin do?

A

Induces maturation and mitosis of BFU-E, CFU-E, and pronormoblast, and developing NRBC cells. Induces increased production of other myeloid cells

65
Q

What produces thrombopoietin?

A

Liver cells

66
Q

What does thrombopoietin do?

A

Induces maturation and mitosis of CFU-meg, and megakaryoblast cells

67
Q

Define effective hematopoiesis

A

When 85% or more of the red blood cells formed in the bone marrow are released successfully. So 15% or less of them die before they are released

68
Q

Define ineffective hematopoiesis

A

When 15% of them die before being released

69
Q

How long to erythroid normoblasts (NRBC)’s survive in each of the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

5 days, 0 days (do not reach blood stream), 0 days (do not reach tissues)

70
Q

How long do reticulocytes survive in each of the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

3 days, 1 day, 0 days (do not reach tissues)

71
Q

How long do fully formed erythrocytes survive in each of the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

1 day, 110-120 days, 0 days

72
Q

How long do megakaryocytes survive in the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

7 days, 0 days (never reach blood stream), 0 days (do not reach tissues)

73
Q

How long do fully formed platelets survive in the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

0 days, 8-10 days, 0 days

74
Q

How long do immature neutrophils survive in each of the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

5 days, 0 days, 0 days

75
Q

How long to fully formed neutrophils survive in each of the following locations of the body:

  • bone marrow
  • peripheral blood
  • tissues
A

7 days, 8 hours, up to 6 days

76
Q

How can the bone marrow increase cell production when demand for blood cells is increased? (4 ways)

A
  1. release immature cells into blood stream (shift left 1 step)
  2. increase the number of mitosis divisions in developing cells
  3. decreasing maturation time/increasing maturation speed
  4. expand hematopoiesis into inactive areas (extra-medullary hematopoiesis)
77
Q

Define amplification

A

When many mature cells are produced from one immature cell (usually a blast cell) by many cell divisions and differentiations

78
Q

List the 4 general morphologic features seen in all blood cells during maturation

A
  1. changes in cell size
  2. changes in nuclear/cytoplasmic ratio
  3. changes in the nucleus
  4. changes in the cytoplasm
79
Q

What changes occur to the cell size during maturation?

A

Cell size progressively decreases

80
Q

What changes occur to the cell’s nuclear/cytoplasmic ratio during maturation?

A

Cytoplasm and nucleus decrease in size at the same time, but the nucleus shrinks faster, so the ratio decreases

81
Q

What changes occur to the cell’s nucleus during maturation?

A

The size of the nucleus decreases, and it loses it’s nucleoli. Increased clumping and coarseness of the chromatin occurs as does increasingly dark staining of the nucleus. It is eventually lost/spit out

82
Q

What changes occur to the cell’s cytoplasm during maturation?

A

A decrease in volume occurs. It changes color from blue to blue/gray or pink

83
Q

Define N/C asynchrony/dyspoiesis

A

When developments of the cell are “out of sync”, either nucleus or cytoplasm shrinking lag behind the other. Usually suggests a metabolic disorder

84
Q

List the steps in the maturation of nucleated red blood cells

A
  1. Pronormoblast (rubriblast)
  2. Basophillic normoblast (prorubricyte)
  3. Polychromatic normoblast (rubricyte)
  4. Orthochromic normoblast (metarubricyte)
  5. Polychromatophillic (reticulocyte)
  6. Erythrocyte
85
Q

Describe the pronormoblast (rubriblast)

A
  • size: 14-24 micrometers
  • has a nucleus that is large and round, unclumped chromtin, 0-2 nucleoli
  • N/C = 8:1 to 6:1
  • cytoplasm is small, deep blue, and has no granules
86
Q

Describe the basophilic normoblast (prorubricyte)

A
  • size: 12-17 micrometers
  • has nucleus that is round, slightly coarser chromatin clumping, parachromatin, nucleoli not visible
  • N/C = 6:1 to 4:1
  • cytoplasm still small, deep blue or purple, no granules
87
Q

Describe the polychromatic normoblast (rubricyte)

A
  • size: 10-15 micrometers
  • has nucleus that is round, deep purple/black, heavily condensed chromatin, parachromatin, no nucleoli
  • N/C = 4:1 to 2:1
  • cytoplasm decreased but increased relative to nucleus, polychromatic, no granules
88
Q

Describe the orthochromic normoblast (metarubricyte)

A
  • size: 8-12 micrometers
  • has nucleus that is round, pyknotic (very dense), black/brown color, not chromatin structure
  • N/C = 1:1 to 2:1
  • cytoplasm moderate, bluish-pink, no granules
89
Q

Describe the polychromatophillic (reticulocyte)

A
  • size: 7-10 micrometers
  • no nucleus, extruded
  • no N/C
  • cytoplasm clear gray-blue, polychromatic to pink
90
Q

Describe the erythrocyte

A
  • size: 7-8 micrometers
  • no nucleus
  • no N/C
  • cytoplasm is pink
91
Q

Describe the red blood cell’s plasma membrane

A

It is bilaminar and surrounds the cytoplasm. It is a double bipolar layer.

92
Q

Name the main parts of the red blood cell’s plasma membrane

A
  • structural and contractile proteins actin and spectrin
  • ATP’ase enzymes
  • surface antigens: glycosphingolipids such as A, B, H blood group antigens and glycoproteins such as M, N antigens
  • receptor protein molecules such as transferrin receptor (TfR)
93
Q

What percentage is each part of the composition of the plasma membrane?

A

50% protein, 40% lipid (24% phospholipid, 12% cholesterol, 4% glycolipid), and 10% carbohydrate

94
Q

What does the lipid in the plasma membrane do?

A

Glycolipids and phospholipids are arranged in two layers with polar group on the outside and inside surfaces, and non-polar groups in the center. Glycolipids act as antigens on the outer surface

95
Q

What does the protein in the plasma membrane do?

A

Structural proteins are integral and penetrate through the membrane or are peripheral and attach to the inside or outside surface where they act as antigens.
Spectrin and actin help maintain the biconcave disk shape.
Band 3 protein acts and a channel to move ions in and out.

96
Q

Why is the plasma membrane sometimes called a fluid mosaic?

A

The lipids of some of the integral proteins can move around the membrane within areas enclosed by spectrin/actin network

97
Q

What do carbohydrates in the plasma membrane do?

A

They are found in a thin mucopolysaccaride layer on the exterior surface and as oligosaccharides that attach to lipids and proteins. Contribute to antigenic properties

98
Q

What are the functions of the plasma membrane?

A

Selective permeability, the ability to selectively allow molecules to move in and out across the membrane.

99
Q

What are the types of transport across the membrane?

A

Diffusion, facilitated diffusion, and active transport

100
Q

Describe diffusion

A

Water and other small, lipid-soluble molecules cross the membrane in response to concentration and electrical gradients

101
Q

Describe facilitated diffusion

A

Some molecules move through the membrane by attaching themselves to special transport molecules in the membrane

102
Q

Describe active transport

A

Movement of molecules across the membrane against concentration and electrical gradients. Requires transport enzymes and energy (ATP)

103
Q

Describe the sodium-potassium pump

A

Na+ moves in and K+ moves out by diffusion. The Na-K pump moves 2 molecules of K+ in and 3 molecules of Na+ out using 1 molecule of ATP. Thus the cell has a high concentration of K+ and low concentration of Na+

104
Q

Describe the calcium pump

A

Calcium accumulates in RBC’s and makes it less elastic. The Ca2+ pump moves calcium out with energy provided by ATP

105
Q

Why do red cell membranes carry a negative charge?

A

This makes the RBC’s repel each other and helps protect them from damage by softening the collisions they make with each other

106
Q

What happens if ATP is unavailable to power the active transport mechanisms?

A

The mechanisms will slow down or fail. Na+ moves back in to the cell, followed by water, causing swelling and the loss of the biconcave shape. Ca2+ builds up and the cell loses flexibility.
This leads to hemolysis

107
Q

What is the RBC’s cytoplasm made up of?

A

90% hemoglobin and 10% other organelles, enzymes, electrolytes, carbohydrates, lipids, and proteins

108
Q

How do mature RBC’s have enough energy to function for 120 days in the blood stream?

A

Developing normoblasts synthesize enzymes, anti-oxidants, and coenzymes, and about 250 hemoglobin molecules

109
Q

When is hemoglobin made?

A

65% of it is made in the developing normoblasts, and 35% is made in the polychomatophillic erythrocytes (reticulocyte)

110
Q

What does hemoglobin production rely on?

A

Adequate iron supply and on synchronized production of heme and globin molecules in the cell

111
Q

What is hemoglobin composed of?

A

Globin protein, composed of 4 polypeptide chains AND four heme molecules attached to one of the globin polypeptides

112
Q

What is the first part of hemoglobin production?

A

Heme synthsis

113
Q

Where is the heme synthesized?

A

The mitochondira and cytoplasm of the developing NRBC’s and reticuloytes

114
Q

The first two steps of heme synthesis, that occur in the mitochondria are:

A
  1. glycine + succinyl CoA
  2. added with Vitamin B6 (coenzyme), HEME, ALA synthetase, and EPO

Produces ALA

115
Q

The steps of heme synthesis that occur in the cytoplasm are:

A
  1. ALA + ALA dehydrase
    Produces porphobilinogen
  2. Porphobilinogen + ALA dehydrase
    Produces uroporphytinogen III
116
Q

The last steps of heme synthesis that occurs in the mithochondia are:

A 
1. Uroporphytinogen III + ALA dehydrase
Produces coproporphyrinogen III
2. Coproporphyrinogen III + ALA dehydrase
Produces protoporphyrinogen IX
3. Protoporphyinogen IX + ALA dehydrase
Produces protoporphyrin IX

**4. Protoporphyrin IX + Iron (Fe2+) and iron chelatase
Procudes: **HEME (ferroprotoporphyrin IX)

117
Q

If iron if deficient what happens to heme production?

A

Less heme is formed and protoporphyrin IX accumulates in excess

118
Q

If any of the enzymes are deficient or inhibited what happens to heme production?

A

Synthesis decreases or shuts down at that point in the sequence and other products are formed and accumulate and cause disease

119
Q

What stimulates the production of globin?

A

The presence of free heme in the cytoplasm of developing NRBC’s

120
Q

Where does globin production take place?

A

The ribosomes

121
Q

What are the types of amino acids that can form globin’s polypeptide chains?

A

Alpha, beta, delta, epsilon, gamma, and zeta

122
Q

How does heme join with globin?

A

One heme bonds by its iron atom to two specific histidine sites. One bond is permanent and the other is reversible

123
Q

How many hemes are there in a hemoglobin molecule?

A

Four identical hemes

124
Q

How to hemoglobins vary?

A

Only by the types of polypeptide chains present

125
Q

List the three embryonic hemoglobins and their polypeptide formula

A
  • Hb Gower 1: epsilon four OR zeta two epsilon two
  • Hb Portland: zeta two gamma two
  • Hb Gower 2: alpha two epsilon two
126
Q

What are the characteristics of the three embryonic hemoglobins?

A

They are produced in the first 12 weeks of gestation in the embryo and early fetus. There is no actual oxygen delivery

127
Q

List the name and polypeptide formula of fetal hemoglobin

A

Hb F: alpha two gamma two

128
Q

What are the characteristic of fetal hemoglobin?

A

At birth Hb F is >75% of total hemoglobin

Adults have

129
Q

List the two types of adult hemoglobin and their polypeptide formulas

A

HbA: alpha two beta two
HbA2: alpha two delta two

130
Q

What are the characteristics of adult hemoglobin A?

A

The most major component, usually 96-98% of hemoglobin

131
Q

What are the characteristic of adult hemoglobin A2?

A

Minor component,

132
Q

What is HbA1c?

A

HbA plus a molecule of glucose attached to the beta polypeptides. Usually accounts for

133
Q

Define reduced hemoglobin

A

HbA where iron is in the ferrous state (Fe2+).

**Ferrous state is required for oxygen binding

134
Q

Define oxyhemoglobin (HbO2)

A

Reduced HbA that is carrying O2 bound to some or all of the iron atoms of the hemes

135
Q

Define deoxyhemoglobin

A

Reduced HbA that is not carrying any O2

136
Q

Define methemoglobin (MetHb)/oxidized hemoglobin

A

HbA where iron is in ferric state (Fe3+). Cannot bind oxygen.

137
Q

What promotes the formation of MetHb?

A

Peroxides and other oxidizing agents, but it is usually reduced to a very small concentation (

138
Q

Define hypoxia

A

Cells starved of oxygen

139
Q

How does MetHb form in excess?

A

Excessive oxidation or reducing system failure/inhibition. Results in hypoxia

140
Q

Define carboxyhemoglobin (HbCO)

A

HbA combining with carbon monoxide. HbA has a higher affinity for CO

141
Q

Define sulfhemoglobin (sulfHb)

A

HbA reaction with soluble, inorganic sulphides and H2O2. One S atom binding with Hb is irreversible and prevents O2 binding

142
Q

What is energy used for in developing NRBC’s?

A

Synthesis of proteins for maturation and mitosis, ie: hemoglobin, membrane proteins, and enzymes for glycolysis

143
Q

What is energy used for in mature RBC’s?

A 
Active transport (Na+, K+, Ca2+), other endergonic reactions
Reducing coenzymes NADH and NADPH
144
Q

How does the RBC get energy?

A

Glycolysis, the release of energy and electrons from glucose. Energy is stored in the phosphate bonds of ATP and electrons reduce coenzymes

145
Q

Name the 2 pathways that produce energy for the RBC

A

Embden-Meyerhof pathway

Pentose Shunt Pathway

146
Q

What does the Embden-Meyerhof pathway do?

A

80-90% of glucose metabolized to lactate.

  1. Each molecule of glucose that enters produces 2 molecules of ATP
  2. Reduction of NAD produces 2 molecules of NADH
147
Q

What does NADH do?

A

A source of electrons to allow the enzyme methemoglobin reductase to convert methemoglobin into reduced hemoglobin

148
Q

What does the Pentose Shunt pathway do?

A

5-10% of glucose is oxidized here.

1. For each glucose molecule one molecules of NADPH is produced by the reduction of NADH

149
Q

What does NADPH do?

A

Used by the enzyme glutathione reductase as a source of electrons to reduce oxidized glutathione (GSSG) into reduced glutathione (GSH).
Also has a minor role in reducing MetHb to Hb

150
Q

What does GSH do?

A

GSH acts with glutathione peroxidse enzyme to prevent oxidative damage to cell membranes by neutralizing oxidizing agents. Protects membrane components and cellular enzymes and hemoglobin from oxidation.

151
Q

What does decreased activity in these glycolytic pathways cause?

A

Premature hemolysis due to membrane damage, enzyme damage, and failure of active transport.

152
Q

What are the three functions of the erythrocyte?

A
  1. Oxygen transport
  2. CO2 transport
  3. Nitric oxide transport
153
Q

How is oxygen transport accomplished?

A

O2 molecules bind to the ferrous iron atoms in hemes of hemoglobin. Each heme binds one O2, so each hemoglobin and carry 4 oxygen molecules. Usually it only carries 3

154
Q

How does reverse oxidation work?

A

Iron atoms can bind and release oxygen molecules several times without become oxidized themselves

155
Q

What is oxygen saturation?

A

It refers to the amount of O2 carried by the hemoglobin in the blood and is expressed by a percentage of the total capacity to carry oxygen

156
Q

What are normal oxygen saturation percentages?

A

95% in arterial blood and 70% in venous blood

157
Q

The amount of O2 carried by hemoglobin is effected by three factors:

A
  1. Availability of oxygen
  2. Availability of enough reduced hemoglobin
  3. Oxygen affinity of hemoglobin
158
Q

What happens when oxygen affinity is high? When it is low?

A

High: hemoglobin easily and quickly bind with oxygen and hang on to them
Low: hemoglobin releases oxygen it is carrying and has difficulty binding with more

Hematology 1 (old) (1 decks)

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