Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cardio > Cardio L18 Thrombosis > Flashcards

Cardio L18 Thrombosis Flashcards

1
Q

Thrombosis

A

Formation of a solid mass from the constituents of the blood within the living circulation.

!!!Distinction from blood clot!!!

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

Blood clot

A

When blood solidifies outside the living circulation the solid and fluid components separate and form blood clots.

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

When a thrombus forms

A

The cellular and serum phases are mixed and form a series of alternating layers of cell poor and cell rich zones.

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

Layers of thrombus

A

Lines of Zahn

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

Arterial site thrombus type

A

Tiny, consisting largely of platelets (Very small dimension)

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

Venous site thrombus type

A

Small and pale; platelet and fibrin rich (Fast local blood flow)

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

Capillaries thrombus type

A

Large and red; Red cell rich (Slow local blood flow)

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

Virchow’s triad →

A

The conditions, which predispose to thrombosis, were first addressed by Virchow in the mid 19th Century.
Changes in the vessel wall
Changes in local blood flow
Changes in co-agulative qualities of the blood

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

Changes in the vessel wall

A

Loss of endothelial integrity (most common: atheroma)

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

Changes in local blood flow

A

Nature of blood flow – laminar vs. turbulent

Disturbance of blood flow allows large numbers of platelets to come into contact with endothelium.

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

Changes in co-agulative qualities of the blood

A 
Alteration in coagulability of the blood
Increased platelet numbers:
1.	Major injury
2.	Surgery
3.	Post partum
Increased fibrinogen concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

→ Thrombus forms at

A

sites of endothelial injury.

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

Intact endothelium tend to discourage thrombosis by 3

A
  1. Expressing sulphated mucopolysacchardies (heparin and heparin like molecules)
  2. Expressing tissue plasminogen activator (TPA)
  3. Synthesizing prostacyclin (PGI2)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The endothelial cell surface is covered by and are potent activators ok

A

covered by sulphated mucopolysaccharides, which carry a large negative charge.

These molecules are potent activators of circulating antithrombotic enzymes such as anti-thrombin 3.

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

Heparin causes

A

A conformational change in the anti-thrombin molecule which enhances its activity a hundredfold.

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

Endothelium expresses

A

Tissue plasminogen activator (TPA)

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

Plasminogen is the

A

Circulating, inactive, precursor of the enzyme Plasmin which destroys thrombus.

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

Endothelial TPA activates

A

Plasminogen with the result that there is active destruction of thrombus at the endothelial surface.

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

Damaged endothelial cells generates

A

Prostacyclin (PGI2)

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

PGI2 function

A

Dilates vessels

Disaggregates platelets

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

Opposition to PGI2

A

Prostaglangin generated by platelets

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

Platelets description

A

Circulating anuclear fragments of the cytoplasm derived from megakaryocytes (multinucleate bone marrow cells, each of which will generate between 2000 & 4000 platelets).

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

Platelets structure

A

3 microns diameter
Conc – 200-400 x 10 to the 9/L
Approx 10 day life span

24
Q

Platelets Contain two sorts of cytoplasmic granules

A

Alpha granules

Dense bodies

25
Q

Alpha granules

A

Coagulation factors
Platelet derived growth factors
Fibrinogen

26
Q

Dense bodies

A

Unique to platelets
Adenine nucleotides (ADP)
5 Hydroxytryptamine
Calcium

27
Q

Platelet Adhesion

A

Rapid adherence to collagen exposed by endothelial damage

28
Q

Platelet releases reaction

A

Degranulation of the platelets

29
Q

Platelet aggregation

A
  1. Platelets rapidly clump together to cover the area of endothelial cell loos
  2. Mediated by ADP and Ca2+
30
Q

Prostaglandins Generated from

A

Cell wall phospholipids, which are released when cells are injured.

31
Q

Endothelial cells generate

A

Prostacyclin (PGI2)

32
Q

Endothelial cells generating prostacyclin (PGI2) function

A

Dilates vessels

Disaggregates platelets

33
Q

Thromboxane produced by

A

Platelets

34
Q

Thromboxane function

A

Constricts vessels

Aggregates platelets

35
Q

PGI2 Function

A

Vasodilation

Platelet disaggregation

36
Q

PGI2 Derived from

A

EPE
PGI3
TXA3

37
Q

PGI3 function

A

Vasodilation

Platelet disaggregation

38
Q

TXA2 function

A

Vasoconstriction

Platelet aggregation

39
Q

TXA3 function

A

Almost without action

40
Q

Diet that reduce thromboxane activity

A

Diets rich in EPE, such as oily fish, evening primrose oil result in reduced thromboxane (TXA3) activity and thus have an anti-thrombotic effect.

41
Q

Virchow’s Triad 2: Co-agulative qualities of the blood:

A
  1. Changes in blood constituents
    a. Alteration in coagulability of the blood
    b. Increased platelet numbers
    i. Major injury
    ii. Surgery
    iii. Post partum
    c. Increased fibrinogen concentration
42
Q

Normal platelet numbers

A

200-400x10(9) /L

43
Q

Platelet numbers Can increase to

A

900-1200 x 10 (9)/L

44
Q

Risk of elevated platelets

A

Increased risk of thrombosis

45
Q

Coagulation Cascade:

A

Consists of a series of circulating plasma proteins which, with the appropriate stimulus, are activated sequentially with the goal of precipitating Fibrin which forms a fibrous mesh, or scaffold, fo the formation of thrombus.

46
Q

Coagulation: steps

A

amplification

Control

47
Q

Amplification

A

The sequential activation of the clotting factors leads to enormous amplification of the initial signal.

48
Q

Control

A

Antithrombin 3

Heparin

49
Q

Anticoagulation

A
  • Enhancing the action of Antithrombin 3 by adding Heparin

* Reducing the concentration of coagulation factors

50
Q

Reducing the concentration of coagulation factors how

A

Achieved by reducing their production in the liver (using dicoumarols such as Warfarin) or by removing the clotting factors from the circulation.

51
Q

Nature of blood flow

A

laminar vs. turbulent.

52
Q

Disturbance =

A

allows large numbers of platelets to come into contact with endothelium.

53
Q

Laminar Flow

A

Minimal mixing between layers
Cellular component of the blood moves in the fast flowing, lower pressure zone, in the centre of the vessel with the result that platelets have little contact with endothelium.

54
Q

Turbulent Flow

A

With disturbance of aminar flow and the introduction of turbulence large numbers of platelets are brought into contact with the endothelial surface.

55
Q

Common Sites for formation of thrombus: arterial

A
  1. Atheromatous plaque
    a. Coronary arteries
    b. Aorta
  2. Endocardium
    a. ‘mural thrombus’
    b. following myocardial
    c. infarction
56
Q

Common Sites for formation of thrombus: venous

A

Venous side of the circulation

  1. Deep veins of the leg
  2. Pelvic veins

Cardio (108 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions