Brainscape's Knowledge GenomeTM

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


See full index

hemostasis > section 5 - coag cascade 1 > Flashcards

section 5 - coag cascade 1 Flashcards

1
Q

name the three major portions of the coag cascade and how they’re related

A
  • intrisic
  • extrinsic
  • common: where intrinsic and extrinsic combine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

describe the extrinsic tenase complex
- constituents and action

A
  • TFIII and Ca activate VII
  • FVII, TFIII and Ca = tenase complex
  • Tenase complex activates factor 10
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe the intrinsic tenase complex
- constituents and action

A
  • contains FIXa, PF3, Ca, FVIIIa
  • activates FX
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the meaning behind a lowercase a by roman numerals ex: VIIa

A

activated factors - more efficient

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

describe the prothrombinase complex
- constituents and action

A
  • contains: Xa, PF3, Ca and Va
  • converts prothrombin (II) to thrombin (IIa)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

list the actions of thrombin

A
  • activates fibrinogen to fibrin
  • activates V, VIII, XI and XIII
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the final steps of the coag cascade

A

fibrinogen -(thrombin)-> fibrin -(XIIIa)-> cross linked fibrin polymer (stable)

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

name the ‘magic four’ factors

A

vitamin K dependent: II, VII, IX and X
-> under warfarin forms incomplete factors

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

true or false
thrombin (factor IIa) is the only substance necessary to convert fibrinogen (FI) to fibrin (Ia)

A

true

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

describe the intrinsic pathway activation steps

A
  • vascular injury exposes collagen
  • collagen contact activates FXII
  • FXIIa activates both XI and pre-kallikren
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define and describe HMWK

A

high molecular weight kininogen
- made in the liver
- contact factor
- cofactor for FXIIa to activate XI
-deficiency leads to thrombosis

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

what is the role of HMWK in the intrinsic pathway

A

in two separate complexes with FXI and PK
facilitates rxns for XI activation and kallikren activation

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

what is the role of FXIa in the intrinsic pathway

A

activates FIX to participate in tenase complex

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

describe the action of HMWK/PK in the intrinsic pathway

A
  • part of clot breakdown and XIIa activation
  • activated to kallikrein via XIIa and activates further XIIa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the role of kallikrein in the intrinsic pathway

A
  • activates further XII
  • using XIIa activates plasminogen to plasmin
  • converts HMWK to bradykinins (part of healing process)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe the alternate pathway

A

extrinsic tenase complex activates IX to take place in intrinsic pathway

17
Q

describe labile factors V and VIII

A
  • only factors that are not enzymes -> co-factors
  • can participate in inactive forms
  • activated by thrombin
  • targets of protein C
18
Q

describe Thrombin (IIa) activity on fibrinogen

A
  • splits fibrinopeptide’s A and B from end of two polypeptide chains of fibrinogen
  • forms fibrin monomer
  • fibrin monomers attach end to end to form fibrin polymer
  • thrombin + Ca = activated XIII to stabilize clot
19
Q

describe fibrinogen (FI)

A
  • made in liver
  • absorbed in platelets alpha granules
  • acute phase reactant
  • increased in pregnancy and smoking
20
Q

describe tissue factor III

A

found in all tissues -> esp brain, liver, lung and placenta
- released when injured
- cofactor for activation of FVII
- part of extrinsic tenase complex

21
Q

describe calcium (FIV)

A
  • mediator of platelet activation
  • low lvls not a problem in vivo
  • in screening tests must add Ca to overcome anticoag
22
Q

describe FV

A
  • activity decreases at room temp
  • attaches to receptor on activated platelets
  • thrombin modified
  • inactivated by protein C
23
Q

describe FVIII - vWF complex

A
  • produced mostly liver (and other tissues)
  • heat labile
  • works with intrinsic tenase complex
  • inactivated by Protein C
  • deficiency = hemophilia A
24
Q

describe FIX (christmas factor)

A
  • activated by XIa or VIIa
  • works in intrinsic tenase complex
  • deficiency = hemophilia B
25
Q

describe FX

A
  • part of prothombinase complex
  • magic 4 - vit K depndent
26
Q

describe FXI

A
  • contact factor
  • complex with HMWK to amplify function
  • activated by XII or thrombin
  • deficiency = hemophilia C
27
Q

decribe FXII

A
  • contact factor with collagen
  • activated with contact to subendothelial tissue
  • deficiency does not mean bleeding
  • defiencey = thrombosis due to lack of clot breakdown
28
Q

describe FXIII

A
  • fibrin stabilizing factor
  • activated by thrombin and Ca
  • forms covalent bonds between D domains in polymerized fibrin
  • deficiency found in urea clot lysis test
29
Q

describe PK (prekallikrein)

A
  • contact factor
  • activates more XII, plasminogen to plasmin, HMWK to Bradykinins for Kini system initiation
  • deficiency = thrombosis due to lack of clot breakdown
30
Q

describe the role of Bradykinins

A
  • increase vascular permeability
  • contract smooth muscle
  • dilate blood vessels
  • induce pain/inflammation
  • release prostaglandins from tissue
31
Q

what is the role of PF3 in coagulation

A
  • phospholipids on the surface provide binding sites for Vit K-dependent factors
  • membranes of activated platelets supply the phospholipids
32
Q

what is the role of DDAVP

A

stimulates release of vWF from endothelial cells

hemostasis (10 decks)

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