Chapter 17 - Blood Pt. 2 Flashcards
1
Q
Characteristics of clot retraction:
A
- stabilises clot
- actin and myosin in platelets contract within 30-60 minutes
- contraction pulls on fibrin strands, squeezing serum from clot
- draws ruptured blood vessel edges together
2
Q
In vessel repair, the vessel is healing as ____ occurs.
A
clot retraction
3
Q
Two factors involved in vessel repair:
A
- platelet-derived growth factor (PDGF)
2. vascular endothelial growth factor (VEGF)
4
Q
Platelet-derived growth factor stimulates:
A
division of smooth muscle cells and fibroblasts to rebuild blood vessel wall
5
Q
Vascular endothelial growth factor stimulates:
A
endothelial cells to multiply and restore endothelial lining
6
Q
Characteristics of fibrinolysis:
A
- removes unneeded clots after healing
2. begins within two days; continues for several
7
Q
In fibrinolysis, plasminogen in the clot is converted to plasmin by:
A
- tissue plasminogen activator (tPA)
- factor XII
- thrombin
8
Q
What is plasmin?
A
a fibrin-digesting enzyme
9
Q
The two mechanisms that limit clot size:
A
- swift removal and dilution of clotting factors
2. inhibition of activated clotting factors
10
Q
Thrombin is bound onto ____.
A
fibrin threads
11
Q
____ inactivates unbound thrombin.
A
antithrombin III
12
Q
Heparin in basophil and mast cells inhibits thrombin by:
A
enhancing antithrombin III
13
Q
Factors preventing undesirable clotting–platelet adhesion is prevented by:
A
- Smooth endothelium of blood vessels prevents platelets from clinging
- Antithrombic substances nitric oxide and prostacyclin secreted by endothelial cells
- Vitamin E quinine acts as potent anticoagulant
14
Q
Disorders of hemostasis:
A
- Thromboembolic disorders
- Bleeding disorders
- Disseminated intravascular coagulation (DIC)
15
Q
undesirable clot formation
A
thromboembolic disorder
16
Q
abnormalities that prevent normal clot formation
A
bleeding disorder
17
Q
involves both undesirable clot formation and abnormalities that prevent normal clot formation
A
disseminated intravascular coagulation (DIC)
18
Q
The different thromboembolic conditions are:
A
- Thrombus
- Embolus
- Embolism
19
Q
What is thrombus?
A
a clot that develops and persists in an unbroken blood vessel; may block circulation leading to tissue death
20
Q
What is embolus?
A
A thrombus freely floating in the bloodstream
21
Q
What is embolism?
A
Embolus obstructing a vessel; e.g. pulmonary and cerebral emboli
22
Q
What are the risk factors of thromboembolic conditions?
A
- atherosclerosis
- inflammation
- slowly flowing blood
- blood stasis from immobility
23
Q
The different anticoagulant drugs are:
A
- aspirin
- heparin
- warfarin
- dabigatran
24
Q
What is aspirin?
A
An antiprostaglandin that inhibits thromboxane A2
25
What is heparin?
An anticoagulant used clinically for pre- and post-operative cardiac care.
26
What is warfarin also known as?
Coumadin
27
What is warfarin used for?
those prone to atrial fibrillation
28
How does warfarin work?
interferes with action of vitamin K
29
How does dabigatran work?
directly inhibits thrombin
30
Different bleeding disorders are:
1. thrombocytopenia
2. impaired liver function
3. hemophilia
31
What is thrombocytopenia?
deficient number of circulating platelets
32
In thrombocytopenia, ____ appear due to spontaneous, widespread hemorrhage.
petechiae
33
Thrombocytopenia is due to:
suppression or destruction of red bone marrow (e.g. malignancy, radiation, drugs)
34
In thrombocytopenia, the platelet count is:
<50,000/microl is diagnostic
35
How is thrombocytopenia treated?
with transfusion of concentrated platelets
36
With impaired liver function, there is an inability to synthesise _____.
procoagulants
37
Impaired liver function is caused by:
1. vitamin K deficiency
2. hepatitis
3. cirrhosis
38
Impaired fat absorption and liver disease can also prevent the liver from:
producing bile
39
Without bile production in the liver, what happens?
impaired fat and vitamin K absorption
40
Hemophilia A is due to:
factor VIII deficiency
41
Hemophilia B is due to:
factor IX deficiency
42
Hemophilia C is due to:
factor XI deficiency
43
Which hemophilia is the most common type?
hemophilia A (77% of all cases)
44
Symptoms of hemophilia include:
prolonged bleeding, especially into joint cavities
45
Hemophilia is treated with:
plasma transfusions and injection of missing factors
46
Treatment for hemophilia leads to increased risk for:
hepatitis and HIV
47
In DIC, clotting causes:
bleeding
48
Characteristics of clotting causing bleeding in DIC:
1. widespread clotting blocks intact blood vessels
| 2. severe bleeding occurs because residual blood is unable to clot
49
When can DIC occur?
1. as a pregnancy complication
2. in septicemia
3. incompatible blood transfusions
50
Whole-blood transfusions are used when:
blood loss is rapid and substantial
51
In blood transfusion, ___ is removed.
plasma and WBCs
52
Packed red blood cells are transfused to restore:
oxygen-carrying capacity
53
Transfusion of incompatible blood can be:
fatal
54
RBC membranes bear 30 types of:
glycoprotein antigens
55
What is the function of antigens?
1. generate an immune response against anything perceived as foreign
2. promoters of agglutination
56
promoters of agglutination are called:
agglutinogens
57
Mismatched transfused blood perceived as foreign may be:
agglutinated or destroyed; can be fatal
58
Presence or absence of each antigen is used to classify:
blood cells into different groups
59
Antigens of ___ and ___ blood groups cause vigorous transfusion reactions.
ABO; Rh
60
Other blood groups that usually have weak agglutinogens are:
1. MNS
2. Duffy
3. Kell
4. Lewis
61
The different types of ABO blood groups are:
1. A
2. B
3. AB
4. O
62
ABO blood group classification is based on:
the presence or absence of two agglutinogens (A and B) on the surface of RBCs
63
Blood may contain agglutinins. What are agglutinins?
preformed anti-A or anti-B antibodies
64
What do agglutinins do?
act against transfused RBCs with ABO antigens not present on recipient's RBCs
65
Anti-A or anti-B antibodies form in blood at about what age?
2 months
66
Adult levels of anti-A or anti-B antibodies are reached by:
8-10 months
67
How many named Rh agglutinogens (Rh factors) are there?
52
68
What are the most common Rh agglutinogens?
1. C
2. D
3. E
69
Rh+ indicates presence of:
D antigen
70
How many of Americans are Rh+?
85%
71
How are Rh- individuals different?
anti-Rh antibodies are not spontaneously formed in Rh- individuals
72
Anti-Rh antibodies form if Rh- individual:
1. receives Rh+ blood
| 2. Rh- mom is carrying Rh+ fetus
73
In Rh- individuals, a second exposure to Rh+ blood will result in:
a typical transfusion reaction
74
Hemolytic disease of the newborn is also called:
erythroblastosis fetalis
75
Erythroblastosis fetalis only occurs in:
Rh- mom with Rh+ fetus
76
What happens in erythroblastosis fetalis?
1. Rh- mom is exposed to Rh+ blood of fetus during delivery of first baby--the baby is healthy
2. Mother synthesises anti-Rh antibodies
3. In second pregnancy, mom's anti-Rh antibodies cross the placenta and destroy RBCs of Rh+ baby
77
The second child of erythroblastosis fetalis can be treated with:
prebirth transfusions and exchange transfusions after birth
78
What is the function of RhoGAM?
a serum containing anti-Rh which can prevent Rh- mother from becoming sensitised
79
Transfusion reactions occur if:
mismatched blood is infused
80
In transfusion reactions, a donor's cells:
1. are attacked by recipient's plasma agglutinins
2. agglutinate and clog small vessels
3. rupture and release hemoglobin into bloodstream
81
A transfusion reaction between donor and recipient's cells can result in:
1. diminished oxygen-carrying capacity
2. diminished blood flow beyond blocked vessels
3. hemoglobin in kidney tubules ---> renal failure
82
Symptoms of transfusion reaction are:
1. fever
2. chills
3. low blood pressure
4. rapid heartbeat
5. nausea
6. vomiting
83
Mismatched blood transfusion can be treated by:
preventing kidney damage--fluids and diuretics are used to wash out hemoglobin
84
Type O:
1. universal donor
| 2. no A or B antigens
85
Type AB:
1. universal recipient
| 2. no anti-A or anti-B antibodies
86
Titles for Type O and AB are misleading because:
other agglutinogens can cause transfusion reactions
87
Autologous transfusions are where:
a patient pre-donates
88
Before transfusion, what is done?
1. blood typing
| 2. cross matching
89
What are the characteristics of blood typing?
1. RBCs with antibodies are mixed against their agglutinogen(s) which causes clumping of RBCs.
2. Blood typing is done for ABO and for Rh factor.
90
What are the characteristics of cross matching?
1. Recipient's serum is mixed with donor's RBCs.
| 2. Recipient's RBCs is mixed with donor's serum.
91
Death from shock may result from:
low blood volume
92
What is blood volume restored/replaced with?
1. Normal saline or multiple-electrolyte solution that mimics plasma electrolyte composition
2. Plasma expanders
93
multiple-electrolyte solution is also known as
Ringer's solution
94
What are examples of plasma expanders?
1. purified human serum albumin
2. hetastarch
3. dextran
95
What do plasma expanders do?
mimic osmotic properties of albumin
96
The different diagnostic blood tests are:
1. hematocrit
2. blood glucose tests
3. microscopic examination
4. differential WBC count
5. prothrombin time and platelet counts
6. SMAC (blood chemistry profile)
7. complete blood count (CBC)
97
hematocrit tests for
anemia
98
blood glucose tests for
diabetes
99
microscopic examination reveals
variations in size and shapes of RBCs, which is an indication of anemia
100
prothrombin time and platelet counts assess
hemostasis
101
SMAC (a blood chemistry profile) tests for
liver and kidney disorders
102
complete blood count (CBC) checks:
formed elements, hematocrit, hemoglobin
103
Fetal blood cells form in:
1. fetal yolk sac
2. liver
3. spleen
104
The primary hematopoietic area by 7th month is:
red bone marrow
105
blood cells develop from
mesenchymal cells called blood islands
106
The fetus forms:
Hemoglobin F
107
What does Hemoglobin F do?
It has a higher affinity for O2 than hemoglobin A formed after birth.
108
Blood diseases of aging are:
1. chronic leukemias
2. anemias
3. clotting disorders
109
Blood diseases of aging are usually precipitated by:
1. disorders of the heart
2. disorders of blood vessels
3. disorders of immune system
