Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Hematology > Episode 5 Hemostasis > Flashcards

Episode 5 Hemostasis Flashcards

1
Q

What is the name of the megakaryocyte stem cell?

A

Hemocytoblast -> Megakaryocyte -> Promegakaryocyte -> Megakaryocyte -> Thrombocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the vasocontrictive phase triggered by?

A

Direct injury itself, SympatheticNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

During platelet plug formation, what do platelets stick to?

A

Exposed collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Platelets stick to exposed collagen thru what receptors?

A

GP 1a receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is von Willebrand’s Factor (vWF) made?

A

They leak out from damaged endothelial cells of blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is vWF found?

A

Plasma, platelets, and walls of blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do GP1b receptors bind to?

A

vWF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens to platelets during adhesion?

A

Platelets will undergo major structural changes and adhesion triggers the secretion of multiple factors from the platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What three major chemicals are released from platelets that adhere to damaged endothelial walls?

A

ADP, TXA2 (Thromboxane A2 or TA2), and Serotonin (5-HT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What becomes of the platelet granules when they degranulate?

A

They become the released factors of ADP, TXA2, and 5-HT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What do the released factors from platelets do?

A

They bind other platelets to stick together and form an aggregate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which platelet receptor participates in aggregation and binding of fibrinogen?

A

GP2b/3a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When does the coagulation phase (blood clotting) occur?

A

It reinforces a platelet plug or stops bleeding when a platelet plug fails

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Roughly how many clotting factors are out there?

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are most of the clotting factors present and in what form?

A

Present in circulation as inactive proteins (zymogens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are inactive clotting factors usually activated by?

A

Other clotting factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which clotting factors are Vitamin K dependent?

A

II, VII, IX, X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the difference b/w extrinsic and intrinsic blood clotting pathways?

A

Extrinsic are initiated outside the blood (via tissue thromboplastin). Intrinsic are initiated within the blood by platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which clotting factors participate in the extrinsic mechanism?

A

III, IV, V, VII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What clotting factor is possessed by all cells?

A

Thromboplastin (factor III), leak out of damaged tissue and finds its way into blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Is factor III normally in blood?

A

No, it leaks out from damaged cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When factor III (thromboplastin) and IV (Ca++) get into the blood, what factor do they activate?

A

Factor VII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Factor VII along with factor V will activate what factor?

A

Factor X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

T/F the extrinsic and intrinsic clotting pathways are initiated simultaneously.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which factor do chemicals released from platelets activate?
Factor XII
26
What does factor XII activate?
Factor XI
27
What does factor XI activate?
IX
28
What does factor IX along with Ca++ and PF3 activate?
Factor VIII
29
What cofactors does factor IX need to activate factor VIII?
Ca++ and PF3
30
What does factor VIII activate?
Factor X
31
T/F both factor VII and factor VIII activate factor X individually
T
32
What does factor X (along with III, IV, V, and PF3) activate?
Prothrombin activator
33
What does prothrombin activator do?
Converts Prothrombin (factor II) into thrombin
34
What does Thrombin do?
Converts fibrinogen (factor 1) into fibrin
35
What does factor XIII and Ca++ (factor IV) do?
Allow fibrin to stick together in forming a fibrin polymer
36
What are three "Natural" anticoagulants?
Thrombomodulin, Antithrombin, Heparin cofactor II
37
What does thrombomodulin bind to?
Thrombin
38
What doe the thrombomodulin-thrombin complex activate?
Protein C (just a plasma protein floating around w/ all of our other proteins!)
39
What is the cofactor of Protein C required to inactivate Factors V and VIII?
Protein S
40
Where is thrombomodulin made?
On the surface of the endothelial cells
41
Where is antithrombin made?
Liver
42
What does antithrombin inhibit?
Factor X and thrombin
43
Where is heparin cofactor II made?
in the liver
44
What does heparin cofactor II inhibit?
thrombin
45
Which two anticoagulant inhibit thrombin?
Antithrombin and heparin cofactor II
46
Which enzyme converts plasminogen to plasmin?
tissue plasminogen activator (tPA)
47
Where is plasminogen made?
Liver
48
What does plasmin do?
Dissolves plasmin - it is a fibrinolytic
49
What cells release tPA?
damaged endothelial cells
50
What happens to tPA?
gets trapped in a clot
51
How is a clot broken down?
tPA and plasminogen were both trapped in clot as it formed, after several days tPA will slowly activate plasminogen
52
What are fibrinolysis inhibitors?
a check and balance on the tPA to prevent prolonged or unwanted degradation of fibrinogen
53
What are two tPA inhibitors?
Plasminogen activator inhibitor 1 and Plasminogen activator inhibitor 2
54
Which two fibrinolysis inhibitors act directly on plasmin to prevent it from dissolving fibrin?
alpha-2-antiplasmin and alpha-2-macroglobulin
55
What are petechia?
pinpoint hemorrhages on skin and mucous membranes
56
How does the CBC test help to assess the clotting system?
Platelet count
57
For coagulation tests, blood is collected in tubes containing what?
Sodium citrate
58
Citrate will bind to what?
Calcium
59
What does the normal functioning of the coagulation cascade require?
Calcium
60
What color tube contains sodium citrate?
Blue
61
What does the prothrombin time (PT) test do?
It assess the extrinsic pathway of the blood clotting cascade
62
Why is calcium added to plasma in the PT test?
To replace the calcium removed by citrate
63
Why is brain thromboplastin added to plasma in the PT test?
To substitute for tissue factor
64
How long does does clotting normally take?
12-15 seconds
65
What is the test clotting time compared to?
A standard normal control in a ratio
66
What was the International Normalized Ratio (INR) devised for?
To standardize test results between different batches and manufacturers of tissue factor
67
What is tissue factor?
Key initiator of the coagulation cascade, formerly known as thromboplastin, AKA factor III
68
What is the ISI?
A fudge factor to come up with a standardized INR
69
What does INR tell you?
How well your blood clots
70
The INR is always used in pts taking which drug?
Warfarin (coumadin)
71
What is the INR number needed for basic blood-thinning needs?
2.0 to 3.0
72
What does an INR of 2.0 to 3.0 mean?
This persons blood usually takes two to three times longer to form a clot
73
If someone is taking coumadin and their INR is 6.2, what does that mean?
They are taking too much coumadin, and have an increased risk for spontaneous bleeding
74
If someone is taking coumadin and their INR is 1.0, what does that mean?
They are not taking enough coumadin! Their risk for forming spontaneous clots
75
What is the difference between the Prothrombin Time (PT) test and the Activated Partial Thromboplastin Time (APTT) test?
PT assess extrinsic pathway and APTT assesses intrinsic clotting pathway
76
In an APTT test why is calcium added?
To replace the calcium removed by citrate
77
In an APTT test why are kaolin and phospholipids added?
To substitute for contact factor, its going to contact FXII and activate it, it is replacing the natural chemicals released from platelets
78
How long does clotting normally take in the APTT test?
25-36 seconds
79
What is APTT most often used for clinically to monitor?
To monitor heparin therapy
80
When is heparin used vs coumadin?
Heparin is used on an inpatient basis, while coumadin is used on an outpatient basis
81
What does UFH stand for?
Unfractionated heparin
82
For someone taking heparin what is a good APTT value?
2-2.5 times that of normal value (so that would be clotting taking 72 seconds to clot, for example, instead of the normal 36
83
What is the Thrombin Clotting Time (TT) test used to assess?
Used to assess the common pathway
84
What do you have to add for the TT test?
Calcium (to replace that removed by citrate) and thrombin (to substitute for the products of the intrinsic and extrinsic pathways)
85
When is the TT test used?
When PT and APPT test is prolonged, particularly when abnormal fibrinogen level or function is considered
86
What are coagulation factor assays used for?
to determine actual deficiencies of specific clotting factors (eg FVII, FIX, etc)
87
Hemophelia A is a mutation in the gene for what factor?
FVIII
88
What would be the result of an APPT test on someone who has Hemophilia A? PT test?
Prolonged APPT. PT would be normal
89
What percentage of Hemophilia A has no family history?
30% (majority are inherited, however)
90
Where are the most serious sites of bleeding in Hemophiliacs?
Joint capsules, skeletal muscles, GI tract, and Brain
91
What is the main cause of pain in joints of hemophiliacs?
Enzymes that breakdown blood in the joints also degrade the bone
92
Which factor is given to pts that experience repeated and painful bleeds into their joints?
FIV (calcium)
93
what is the most common bleeding disorder?
Von Willebrand's Disease (vWD)
94
What are the two major roles of vWF?
mediating platelet adhesion and stabilizing factor VIII
95
Where is bleeding typically seen in vWD?
skin and mucous membranes
96
Which test result is similar and which one is different for Hemophilia A and vWD patients?
Both pts would have prolonged APPT and reduced FVIII clotting activity (intrinsic pathway). However, PT is only prolonged in vWD patients. In Hemophilia A PT is normal
97
Why is the PT test in vWD pts prolonged?
Failure of platelet-vessel wall interaction
98
What are the common causes of thrombocytopenia?
Impaired production of platelets (drug induced or bone marrow failure). Increased destruction of platelets (idiopathic thrombocytopenic purpura (ITP))
99
What is ITP?
autoimmune response to platelets, which are removed prematurely by the reticuloendothelial system
100
What are some examples of inherited thrombophilias?
Protein C deficiency Protein S deficiency Activated Protein C Resistance (poor response by FV, FV is not inactivated by Protein C like it should be) Antithrombin III deficiency
101
What is Hemophilia B a mutation in?
Mutation in FIX
102
What are the APPT and PT test results for Hemophilia A and B?
APPT is prolonged; PT is normal. These are in contrast to vWD which has a prolonged PT as well
103
How can FV Leiden be treated?
Give normal FV. The FV the person has does not re

Hematology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions