Paper 2 Physiology

Question 1

APTT is for the

Answer 1

Intrinsic pathway

Question 2

PT is for the

Answer 2

Extrinsic pathway

Question 3

Factors of intrinsic pathway

Answer 3

12 > 11 > 9 > 8 > 10

Question 4

Factors of extrinsic pathway

Answer 4

Truma > 7 and TF > 10 (common)

Question 5

Common pathway

Answer 5

10 > 5 > 5 +10 (prothrombane complex)

Converts prothrombin to thrombin which activates platelets

Question 6

Platelet plug injury

Answer 6

1. Endothelial injury
2. Collagen exposed, damaged cells release vWF
3. GP1B protein on platelets bind to vWF
4. Platelets stick, release prothrombane for positive feedback loop
5. GP11B/IIIA bind to fibrinogen

Question 7

Natural anticoagulants

Answer 7

• TFPI
  
  • Inhibits F7 and F10
• Protein C
  
  • Binds to co-factor protein S
  • Inhibits 5 and 8
• Antithrombin
  
  • Inhibits 10 and thrombin

Question 8

Vitamin K dependent factors

Answer 8

2, 7, 9, 10

Question 9

What do protein C and S do

Answer 9

Protein S is a co-factor of C which inactivates V and VIII

Question 10

What are vasodilators

Answer 10

Prostaglandins and nitrous oxide

Question 11

Important natural anticoagulatns

Answer 11

TFPI (inhibits 8 and 10)

Protein C and S (inhibits 5 and 8)

Antithrombin (inhibits 10 and 2)