Heme 2.5 Flashcards

1
Q

how is any local bleeding “arrested”

A

intereaction between platelets and blood vessel endothelial cells, fallowed by cascade of coagulation

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

what is hemostasis desiged to ensure

A

there is no major leakage of blood following injury and consists of a complex system proteins and enzymes

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

what is thrombosis

A

clots forming to easily

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

how many platelets can a single megakaryocite produce

A

around 3000

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

what amount of platelets are pooled in the spleen

A

about 20-30%

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

what is the average lifespan of a platelet

A

5-20 days

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

what artery layer is important for hemostasis

A

connective tissue layer (within the tunica intima)

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

what triggers vasoconstriction in arteries and vains

A

the direct injury itself

sympathetic nervous system

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

descrive platelet plug formation

A
  • aggregation of platelets
  • platelets stick to exposed collogen, swell, and form spiked process
  • platelet plugs are effectin in preventing blood los due to small injuries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do platelets tick to exposed collagen of damaged endothelium

A

GPIa receptors (GP=glycoproten)

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

what is von Willebrand’s Factor (vWF) and what receptor does is use

A

via GBIb receptors, it speciffically causes platelets to attach firmly to and spread across the damaged endothelial surface.

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

what happens to platelets when they adhere

A

the will indergo major structural changes and deformities

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

what three things are stored within platelet granules

A

ADP
Thromboxane (TA2; TXA2; a prostaglandin)
serotonin (5-HT)

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

what does fibrinogen bind to to link platelets together

A

GPIIb/IIIa

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

what is the process of the cuagulation phase

A
  • occurs either to reinforce a platelet plug of to stop blead when a platelet plug fails
  • involved numerous clotting factors which are often indicated by roman numerals
  • most(not all) clotting cafros are proteins and are synthesized by the liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are most clotting factors existing as

A

zymogens (inactive form in the blood)

17
Q

clotting factor I (name and location

A

fibrinogen, liver

18
Q

CF II

A

prothrombin, liver

19
Q

CF III

A

tissue factro or thromboplastin, perivascular tissue

20
Q

CF IV

A

calcium, Plasma

21
Q

what are the vitamin K dependant CF

A

II, VII, IX, X

22
Q

CF V

A

proaccerlerin, LIVER

23
Q

CF VII

A

proconvertin (stable factor), liver

24
Q

what is the blood clotting cascade

A

comprises intrinsic and extrinsic pathways- both are initiated mimultaneously and lead to final common pathway

25
intrinsic pathway
initiated within the blood
26
extrinsic pathway
initiated outside the blood
27
what does the common pathway begin
when factor X is initiated
28
what are three "natural" anti-coagulants
- thrombomodulin - antithrombin III (or just antithrombin) - Heparin cofactor II
29
what is inside a true clot
red cells, fibrin and proteins
30
Where can Von Willebrands factor be found
a protein found in plasma, platelets, and the walls of blood vessels