Hemostasis Flashcards

1
Q

What is HEMOSTASIS?

A

The stoppage of bleeding

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

HEMOSTASIS occurs in response to…

A

BLOOD VESSEL damage

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

What triggers HEMOSTASIS?

A

CHEMICALS released or activated by damaged CELLS and PLATELETS

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

Two F’s of HEMOSTASIS:

A

1) Prevent BLOOD loss

2) Build frame for TISSUE repair

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

What are the three steps of HEMOSTASIS?

A

1) VASCULAR PHASE
2) PLATELET PHASE
3) COAGULATION

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

What happens when a damaged VESSEL has a VASCULAR SPASM?

A

The VESSEL constricts, and the SMOOTH MUSCLE contracts, thus decreasing BLOOD flow

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

What do ENDOTHELIAL CELLS (lining BLOOD VESSELS) release?

A

ENDOTHELINS (peptide hormones)

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

Three F’s of ENDOTHELINS:

A

1) Stim. contraction of SMOOTH MUSCLE in BLOOD VESSEL wall
2) Make ENDOTHELIUM sticky
3) Stim. CELL division/repair

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

COLLAGEN FIBERS are exposed when ___________ is damaged

A

ENDOTHELIUM

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

What sticks to the exposed COLLAGEN FIBERS?

A

PLATELETS

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

What stabilizes bound PLATELETS?

A

A PLASMA PROTEIN called the VON WILLEBRAND FACTOR (vWF)

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

As PLATELETS become sticky, other PLATELETS _________

A

Aggregate

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

The adhesion/aggregation of PLATELETS results in what?

A

A PLATELET PLUG

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

Activated PLATELETS release granules containing these four substances:

A

1) SEROTONIN
2) THROMBOXANE A2 and ADP
3) PDGF aka PLATELET derived growth factor
4) Ca2+

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

F of SEROTONIN:

A

F - Stim. VASCULAR SPASM and PLATELET aggregation

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

F of THROMBOXANE A2 and ADP:

A

F - Stim. PLATELET aggregation

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

F of PDGF:

A

F - Promotes VESSEL repair

18
Q

F of Ca2+:

A

F - Promotes COAGULATION

No Ca2+, no COAGULATION

19
Q

As more PLATELETS aggregate, more chemicals are released, attracting more PLATELETS. This is ________ ________

A

POSITIVE FEEDBACK

20
Q

When BLOOD goes from liquid to gel it is known as:

A

COAGULATION aka BLOOD CLOTTING

21
Q

A CLOT = ?

A

A tangle of FIBRIN (a FIBROUS PROTEIN) and CELLS

22
Q

What triggers CLOT formation?

A

Sequential activation of CLOTTING FACTORS

23
Q

What are CLOTTING FACTORS?

A

PROTEINS in BLOOD; many are ENZYMES

24
Q

CLOTTING FACTORS circulate as what?

A

Inactive PROCOAGULANTS

25
What must be activated for COAGULATION to occur?
The inactive PROCOAGULANTS circulating
26
Where are most CLOTTING FACTORS made?
In the LIVER
27
How many COAGULATION PATHWAYS are there?
Two; the INTRINSIC PATHWAY and the EXTRINSIC PATHWAY`
28
Where is the INTRINSIC PATHWAY initiated?
Within the BLOOD
29
When is the INTRINSIC PATHWAY triggered?
When CLOTTING FACTOR XII and PLATELETS are activated by COLLAGEN
30
What is required for the INTRINSIC PATHWAY
PLATELET PHOSPHOLIPID (PF3)
31
When is PF3 expressed?
When PLATELETS are exposed to COLLAGEN (COLLAGEN is in CT and walls of torn BLOOD VESSELS)
32
What can occur when BLOOD is exposed to glass and why?
COAGULATION, glass has a negatively charged surface that has the same effect as COLLAGEN
33
Where is the EXTRINSIC PATHWAY initiated?
By chemicals external to the BLOOD
34
What activates the EXTRINSIC PATHWAY?
A chemical released by damaged CELLS
35
What chemicals do damaged CELLS release?
TISSUE FACTOR (TF)/THROMBOPLASTIN
36
What does TF activate?
PLATELETS
37
Which COAGULATION PATHWAY is faster?
EXTRINSIC; < two minutes, whereas INTRINSIC = two - three minutes
38
*Both* PATHWAYS activate ________ ______ _
CLOTTING FACTOR X
39
What does CLOTTING FACTOR X initiate?
The COMMON PATHWAY
40
What does the COMMON PATHWAY result in?
A network of FIBRIN
41
Normally, *both* PATHWAYS are activated simultaneously by ______
Injury