Chapters 4-5 Flashcards
(114 cards)
0
Q
What is extravascular catabolism?
A
Happens inside the cells of the spleen. The hemoglobin gets chewed up. Polypeptide chains are broken apart and the amino acids are recycled. Iron is transported back to marrow for erythropoiesis.
1
Q
When heme is broken apart, it is converted into what? And then excreted too the GI tract by the liver.
A
Bilirubin
2
Q
What is intravascular catabolism?
A
This happens inside the circulating blood. Less than 10% of RBC catabolism happens this way. RBCs hemolyze (pop) causing them to release cytoplasm into plasma.
3
Q
What is haptoglobin?
A
A plasma protein that binds polypeptide chains, preventing their loss in urine.
4
Q
What is the Luebering-Rapaport Pathway?
A
Regulates 2-3 DPG concentration in RBCs.
5
Q
What is the Embden-Meyerhof Pathway?
A
- Main energy source
- ATP from glucose
6
Q
What is the hexosemonophosphate shunt?
A
Prevents oxidative denaturation of hemoglobin and Heinz Body formation.
7
Q
What is the Methemoglobin Reductase Pathway?
A
Prevents oxidation of hemoglobin iron to ferric iron.
8
Q
What is electrophoresis?
A
Analytical technique that separates molecules according to their different migration rates in an electric field.
9
Q
What is carboxyhemoglobin?
A
This happens when carbon monoxide replaces oxygen. Hemoglobin binds carbon monoxide and releases it very slowly. It cannot transport oxygen. Affinity for CO > 200 times that of Carbon Dioxide.
10
Q
What is sulfhemoglobin?
A
- Hemoglobin that combines with sulfur compounds.
- Hemoglobin shape get altered, preventing oxygen transport.
- Can bind carbon monoxide.
- May denature and precipitate to form Heinz Bodies.
Common Causes:
Drugs and bacterial infections
11
Q
What are methemoglobin?
A
- Hemoglobin with Ferric Acid iron.
- Cannot bind oxygen.
- Caused by genetic defects or oxidizing drugs.
12
Q
What are hemoglobinopathies?
A
Diseases of abnormal hemoglobin.
13
Q
What is erythropoietin?
A
A glycoprotein hormones (growth factor) that stimulates erythropoiesis. Produced by kidneys in response to hypoxia. Travels to bone marrow and stimulate RBC HPCs (stem cells).
14
Q
What is hypoxia?
A
Decreased oxygen.
15
Q
What is erythropoiesis?
A
Production of red blood cells.
16
Q
What is Absolute (2 degree) Polycythemia?
A
- Increased numbers of RBCs
- Increase in erythropoietin
- Happens to smokers, chronic lung disease, abnormal hemoglobin molecule, renal tumors, and genetic disorders.
17
Q
As cells mature…
A
- ) Cells get smaller
- ) Cytoplasm gets lighter
- ) Nuclear chromatin condenses, gets thicker.
- ) Eventually lose the nucleus.
- ) Nucleoli disappears.
- ) Mature cells have lower N/C ratios.
18
Q
What are totipotential stem cells?
A
They have the total potential to develop into any human cell type, including development from embryo to fetus.
19
Q
What are pluripotential stem cells?
A
These are present several days after fertilization. Can develop into any cell type, except they cannot develop into a fetus.
20
Q
What are multipotential stem cells?
A
Can be found in adults, but are limited to specific types of cells to form tissues.
21
Q
What is heme?
A
- An iron-bearing compound that is the nonprotein pigment portion of the hemoglobin molecule.
- Responsible for oxygen and carbon dioxide transport.
22
Q
What is polychromatophilia (polychromasia)?
A
Fine, evenly distributed basophilic (blue) granules that impact a blue color to Wright-stained erythrocytes.
23
Q
What is a rubriblast?
A
- AKA Pronormoblast
- 1st stage in maturation cycle of RBCs.
- Fine chromatin, 0-2 Nucleoli, Basophilic cytoplasm, receives iron for hemoglobin.
24
What is a prorubricyte?
- AKA Basophilic Normoblast
- 2nd stage in Maturation Sequence
- Thicker Chromatin
- Possible Nucleoli
25
What is a rubricyte?
- AKA Polychromatic Normoblast
- 3rd stage
- Coarse chromatin, muddy grey cytoplasm, 1st visible hemoglobin.
26
What is a metarubicyte?
- AKA Orthochromatic Normoblast
- 4th stage
- Pyknotic nucleus (dark solid)
- Pinkish cytoplasm
27
What is a reticulocyte?
- 5th stage
| - Anuclear RBC with bluish tint
28
What is an erythrocyte?
- Final stage, matured RBC.
| - Anuclear, pinkish red cytoplasm
29
How long do RBCs live?
120 days or four months
30
What is the stain used to determine if fetal blood is in the mother's blood? What color do the hemoglobins turn?
Kliehauer - Betke stain.
Stains RBCs with Hgb F with dark pink "spots"
Stains RBCs with Hgb A with pale "spots"
31
What is a hematocrit?
Test that measures the percentage of volume of whole blood that is made up of RBCs.
32
How long do reticulocytes live?
1-2 days
33
What are amino acids?
This is what polypeptide chains are made of. They are the building blocks of life and combine to form proteins.
34
What is a chloride shift?
This is the exchange of bicarbonate (HCO3) and chloride (CL-) across the membrane of red cells.
35
What organ synthesizes erythropoietin?
Kidneys
36
What growth factor stimulates erythropoiesis?
Erythropoietin.
37
Cytoplasm stains ____________ as cells mature.
Lighter
38
What is a neoplasm?
A tumor, or abnormal mass of tissue as result of abnormal growth or division of cells.
39
Where does hematopoiesis occur after four months of gestation and overtakes the liver/spleen after six months gestation and remains the dominant location for hematopoiesis till death?
Bone marrow
40
By 2 months gestation, what is the dominant site of hematopoiesis? When does this site become inactive?
Liver/Spleen. Decreases after through birth and is inactive once baby is born. The liver retains hematopoietic capacity if needed.
41
As blood cells mature, what happens to the nucleoli?
It's not visible in matured cells.
42
What is the polypeptide chain of Hemoglobin A?
2-Alpha, 2-Beta
| This makes up 95-97% of hemoglobin in adults and children.
43
What is the polypeptide chain of Hemoglobin A2?
2-Alpha, 2-Delta
| 2-3% in Adults
44
What are some symptoms of porphyrias?
Anemia, neurological effects, light sensitivity, and unusual hair growth.
45
What is porphyrias?
Inability to synthesize heme.
46
What does hemoglobin synthesis require?
Amino acids, iron, and vitamins B, B6, B12, and Folic Acid.
47
How long does it take for normal Reticulocytes to mature?
One day
48
Stress retics require _________ to mature.
Longer
49
What is transferrin?
A protein that transports iron.
50
What is a stress reticulocyte?
Retics that are released from the marrow earlier than normal and require longer than one day to mature.
51
What are polypeptide chains?
These are chains made of amino acids. There are four in a hemoglobin molecule.
52
What are some abnormal types of embryonic hemoglobins?
Hgb Portland, Hgb Gower I, Hgb Gower II
53
What are the subunits in the Barts Hemoglobin?
4 Beta units
54
What are the units in Hemoglobin H?
4 Beta
55
What are the units in Hemoglobin S? Why is this a pathologic hemoglobin?
2 Alpha - 2 Beta but part of the chain received the wrong amino acid.
56
What are the units of Hemoglobin C? Why is this a pathologic hemoglobin?
2 Alpha - 2 Beta but received wrong amino acid.
57
What are Hemoglobin F polypeptide chains composed of?
2 Alpha - 2 Gamma
58
What increases when there is a loss of oxygen to the tissues? What does this molecule do?
2, 3 - DPG binding, it helps increase the release of oxygen to the tissues.
59
What enhances 2,3 - DPG production by the RBC?
Hypoxia
60
2,3 - DPG combines with _________'s beta chains, ___________ its affinity for oxygen. Oxygen ______ the RBCs.
1. Hemoglobin
2. Decreasing
3. Leaves
61
How many polypeptide chains are there in a hemoglobin molecule?
Four
62
How many heme groups are in a hemoglobin molecule?
Four
63
How many iron molecules are in a hemoglobin molecule?
4 iron molecules, one in each heme group.
64
What is hematopoiesis?
Production, formation, and development of all blood cells.
65
What is a "right" shift?
This happens in an oxygen dissociation curve and means there is a decreased carbon dioxide affinity.
66
What is a "left" shift?
Increased carbon dioxide affinity.
67
What is relative (1 degree) polycythemia?
This happens when there is decreased plasma volume. Caused by dehydration. RBCs do not get increased.
68
Bigger a cell is, the more __________ it is.
Immature.
69
What is the Corrected Reticulocyte Count?
A mathematical adjustment of the reticulocyte count to account for variations caused by erythrocyte quantity.
Formula:
Corrected RETIC Count = (patient HCT/normal HCT) x uncorrected retic count %
70
What is polycythemia?
Increased RBC concentration.
71
What is procrit?
A genetically engineered erythropoietin molecule synthesized by hamster ovary cells.
72
What are the functions of RBC?
Transportation of oxygen from lungs to tissue by RBC hemoglobin. And transportation of CO2 (carbon dioxide) from tissues to the lungs.
Brings oxygen in, takes CO2 out.
73
Should you let RBCs get too high?
No, blood will get too thick and blood pressure will go up.
74
Cancer treatment patients are often very anemic, why?
Chemotherapy kills stem cells so they aren't producing enough RBCs.
75
What does the reticulocyte count do?
Measures bone marrow erythropoiesis.
76
What is the normal retic count in adults and newborns?
Adults: 0.5-2.5%
Newborns: 2.5-6.0%
77
In order to bind with oxygen, this substance must be in what valence?
+2
78
How many oxygen molecules can one hemoglobin bind with?
4
79
Where on the hemoglobin molecule is oxygen bound to?
Iron Ion
80
When cells in the body utilize energy, they produce ________ __________.
Carbon dioxide.
81
Why does carbon dioxide enter into the RBCs?
Diffusion. Carbon dioxide wants to go from low concentration area to high concentration area.
82
Once carbon dioxide enters the RBC, it reacts with water to produce what acid?
Carbonic Acid
83
What RBC enzyme promotes this chemical reaction?
Carbonic anhydrase
84
Once produced, carbonic anhydrase disassociates into ____________ and ___________.
HCO3- and H+
85
What substance diffuses out of the RBC back into the plasma?
Bicarbonate
86
What substance diffuses into the RBC to take its place and maintain electrical neutrality?
Chloride
87
Each RBC contains ____ million hemoglobin molecules.
270
88
Of all the cells in a human, approximately ___% are RBCs.
25
89
What is the advantage of the RBC eventually losing its nucleus?
To make space for hemoglobin.
90
What is the clinical significance of the Reticulocyte Count?
The Retic Count measures bone marrow erythropoiesis.
91
How can a reticulocyte be recognized on a Wright Stain peripheral blood smear?
It has a bluish discoloration because it briefly retains the RNA.
92
Another name for Reticulocyte?
Polychromatic RBC
93
How can a stress reticulocyte be visually differentiated from a normal Reticulocyte?
Stress reticulocytes are immature, larger than normal, and have a darker bluish color.
94
What are the purple "spots" observed in Reticulocytes when stained with methelyene blue?
RNA ribosomes
95
List three layers formed when blood is centrifuged..
Platelets and white blood cells, red blood cells, and plasma.
96
What is the normal hematocrit for a pregnant female?
35%
97
What is the normal hematocrit for a fetus?
55%
98
Why does having more blood cells as a baby help the fetus bind with oxygen?
Since the baby has more red blood cells,it can take up more oxygen.
99
Where does 2-3 DPG bind with the hemoglobin molecule?
At the Beta Sub Units
100
What is the general effect of 2,3 - DPG on hemoglobin's ability to bind with oxygen?
It helps the RBC get rid of oxygen. Making it easier for oxygen to be released from hemoglobin.
101
Does 2,3 -DPG bind better with Hgb A or Hgb F?
Hgb A
102
How does hypoxia affect 2,3 - DPG concentrations in RBCs?
Makes 2,3 - DPG levels go up.
103
A "right" shift is associated with _________ 2,3-DPG concentrations.
High
104
A "left" shift is associated with ____ 2,3-DPG concentrations.
Low
105
How is Hgb F a better hemoglobin for a fetus instead of Hgb A?
Hgb F bind oxygen more tightly and has a lower P50.
106
What organ removes the majority of old RBCs from the peripheral blood?
Spleen
107
What gas causes the formation of caboxyhemoglobin?
Carbon monoxide
108
What techniques uses the movement of molecules in an electrical field to separate and identify different hemoglobins?
Electrophoresis
109
The removal of RBCs by the RE system is called ______________ catabolism.
Extravascular
110
What organ is responsible for the excretion of bilirubin into the bile ducts?
Liver
111
What is bilirubin?
Heme
112
What is the formula for uncorrected retic count?
(retics/# of rbcs) X 100
113
What is the RPI formula?
Corrected Retic count/maturation time
