Blood Clot Flashcards Preview

MCB 2 Block 3 > Blood Clot > Flashcards

Flashcards in Blood Clot Deck (24):
1

Platelet products

Alpha granules, Dense granules, and Thromboxane A2
From megakaryocytes

2

Platelet Alpha granules

vWF promotes platelet adhesion to collagen. Synth in vesicular cells and megakaryocytes, self polymer.
Free floating vWF binds to factor 8 and stabilizes it

3

Platelet Dense Granules

ADP = platelet activator
Serotonin = vasoconstrictor

4

Platelet Thromboxane

TXA2 is a potent platelet activator
Inhibited by aspirin

5

Overview of blood coag

1. Vasoconstriction: seals vasulature so no excess bleed
2. Platelet Activating factor: forms platelet plug (adhesion, aggregation, secretion)
3. Form fibrin meshwork (soft to hard clot)
4. Fibrinolysis: removes clots

6

Platelet activation: Adhesion

Vascular damage leads to exposed collagen which activates platelets. Free vWF binds collagen and GP1b on platelet binds vWF.

7

Platelet activation: Secretion

Secretes: ADP, Serotonin, vWF, TXA2, Fibrinogen. These along with epi, thrombin, and PAF turn on other platelets

8

Platelet Activation: Aggregation

Brings together activated platelets. Released fibrinogen sticks everything together by binding GP2b/GP3a on platelet membrane

9

Intrinsic Pathway

Factor 12 exposed to collagen activates it to 12a.
12a activates factor 11 which activates 9 on phosphatidyl serine flipped to outer leaflet
8a and 9a together activate 10
5a and 10a together activate 2 (prothrombin to thrombin)

10

Extrinsic Pathway

Trauma induces factor 7a, 7a activates 9 (same as intrinsic)
Factor 7a with TF will activates 10 (Ca makes connection btwn carboxylated Glu in Gla domain and neg charged surface of platelet coming from phosphatidyl serine)
Factor 5a and 10a together activates 2 (prothrombin to thrombin)

11

Both pathways

Factor 2a/thrombin activates 1 (fribrinogen to fibrin = soft clot). Thrombin removes negative charges on fibrinogen so binding can occur).
Factor 13 is activated by thrombin which is a transglutamidase which forms cross linked hard clot

12

All pathways drawn

on paper

13

Facts about clotting

Most clot factors are made in liver in zymogen form, activated forms are serine proteases (serine proteases cut at carboxy terminal side of Arg in zymogens)

Calcium is required for most steps

Carboxylation is vit K dependent and is needed for carboxy of prothrombin, protein C, protein S, factors 7 9 10 in order for them to stick on membrane

14

Thrombin information

Is self limiting. Binds to thrombomodulin on endo cell surface. Activates APC which binds protein S to inhibit factors 5a and 8a

15

Natural Anti-Coag

Antithrombin is a serpin (serine protease inhib), inactivates Ser proteins (10a and thrombin) and is activated by heparin

16

Fibrinolysis

Plasminogen floats around and activated by tPA and uPA to plasmin which degrades fibrin clots

17

Glanzmans Thromboasthemia

Def in GP2b/GP3a leading to aggregation problems and severe bleeding

18

Von Willebrands Disease

mut in vWF leading to defect in platelet aggregation, pt bleeds out

19

Von Willebrands Disease Table Drawn

On paper

20

Factor 5 Leiden

Factor 5a resistant to APC due to missense mutation leading to continuous clotting

21

Hemophilia

X-linked
A = Factor 8 and flip inversion
B= Factor 9 and is Christmas disease
Tx= infuse missing factor

22

Plavix

Antithrombatic
Interferes with GP2b/GP3a/fribrinogen leading to aggregation misfx

23

Coumarin/Warfarin

Inhibits Vitamin K leading to inhib of carboxylation of clot factors therefore inhibiting clotting

24

Thrombatic Therapy

Plasminogen activating, breaks clots for MI's and stroke
tPA=activase
uPA = abbokinase
Streptokianse = steptase