101

Question 1

mechanisms that naturally keep blood thin

Answer 1

Nitric Oxide and PGI2 (prostacyclin)
Heparin sulphate binds anti thrombin 3 and activates - degrades CF 2,9,10
Thrombomodulin binds thrombin (2) and activates protein c - degades CF 5,8

Question 2

Mechanisms of Haemostasis

Answer 2

Vascular spasm
Platelet plug formation
Coagulation
clot retraction and repair
Fibrinolysis

Question 3

Effects in Vascular spasm

Answer 3

1. Endothelin
2. Myogenic mechanism
3. Nociceptor activation

Question 4

Platelet plug formation

Answer 4

vWF exposed and bind with platelets via Gp1b - platelets release chemicals ; ADP, TXA2, Serotonin.
Platelets activates and aggregate via binding to each other with fibrin via GPIIb/IIIa

Question 5

Platelet chemicals

Answer 5

ADP - lead to activation of platelets to cause aggregation at injury site
Thromboxane A2 - lead to activation of platelets to cause aggregation at injury site
Bind to smooth muscle to cause contraction
Serotonin -Bind to smooth muscle to cause contraction
enhances vasco spasms

Question 6

CF XIII

Answer 6

Fibrin cross linking to produce fibrin mesh network

Question 7

Coagulation

Answer 7

Intrinsic Pathway (4-6 mins)
XII-XI-IX+VIII -X
X-Xa - Common pathway
Extrinsic Pathway (30 secs) III +VII (Stimulate activation of IX and also activation of common pathway X-Xa join active pathway

Question 8

Factor III

Answer 8

produced by damaged tissue

Question 9

Extrinsic pathway

Answer 9

Tries to drive IX-IXa or X-Xa

Question 10

Clot retraction and repair

Answer 10

Platelet contraction
Release of PDGF (Platelet derived growth factor) - trigger proliferation of smooth muscle for repair
Vascular Endothelial Growth Factor (VEGF) - regenerate new endothelial area

Question 11

Fibrinolysis

Answer 11

Plasminogen converted to Plasmin via TPA(Tissue Plasminogen Activator).
Break down Fibrin - release of fibrinogen and D-dimer

Question 12

Heparin

Answer 12

Enhance Antithrombin 3 activity - Co factors disruptec

Question 13

Clopidogrel

Answer 13

Inhibits ADP

Question 14

Aspirin

Answer 14

Inhibits Thrombaxane A2

Question 15

Abciximab

Answer 15

Inhibits the GpIIa/IIIb connection

Question 16

Dabigatran (Prodaxa)

Answer 16

Inhibit activation of factor II

Question 17

Warfarin

Answer 17

inhibits Vit K - limiting clotting factors

Question 18

Diseases of platelet adhesion

Answer 18

Bernard-Soulier-Def GPIb

von Willebrand disease - def in vWF

Question 19

Diseases of platelet aggregation

Answer 19

Glanzmann thrombasthenia - Def GPIIb/IIIa

Afibrinogemaenia - Def in Fibrinogen

Question 20

Platelet abnormality condition

Answer 20

Grey platelet syndrome - deficiency in alfa granules

Wiskott-Aldrich syndrome - deficiency in dense granules

Question 21

Alpha granules

Answer 21

Secrete - vWF and fibrinogen

Question 22

Dense granules

Answer 22

Serotonin
ADP
Ca2+

Question 23

Coagulation disorders

Answer 23

Haemophilia A - def VIII (Anti haemolytic factor A)

Haemophilia B - Def in IX

Question 24

Anticoagulation molecules

Answer 24

TFPI - limits production of thrombin in initiation phase (extrinsic pathway)
Antithrombin - limits amplification (intrinsic and common pathway) 2,9,10
Protein C and S - limit cofactors VIII and V

Question 25

Clot removal

Answer 25

Fibrinolysis
Plasminogen - plasmin via TFPI - Tissue Factor Protein Inhibitor
Bradykinin - a vasodilator. Reverses effect of serotonin and PG