Examplify 4

Question 1

mode of action of aspirin

Answer 1

it leads to a reduction in the synthesis of thromboxane A2, meaning reduced platelet aggregation

–> via irreversibly inhibiting cylooxygenase-1

Question 2

cylooxygenase-1

Answer 2

produces thromboxanes from a arachidonic acid

Question 3

thromboxane A2

Answer 3

activates platelets

Question 4

name 3 of the 12 clotting factor now identified by their names or Roman numerals

Answer 4

protein C (factor IV) and thromboplastin (factor III)

Question 5

most clotting factors are

Answer 5

synthesised in the liver

Question 6

a 72 year old man develops sudden onset abdominal pain and collapses. On admission he is found to have a leaking AAA. His aneurysm is repaired and he is transfused 10 units of blood. After the operation he is found to be thrombocytopenic. What is most likely explanation for this?

Answer 6

Blood transfusion

• blood stored for more than 24 hours does not contain platelets

Question 7

in Von Willebrand disease which tests of clotting are most likely to be abnormal?

Answer 7

APTT and bleeding time- both will be raised

Question 8

Von willebrand disease

Answer 8

due to a deficiency or abnormality in Von Willebrand factor.

Question 9

Von Willebrand factors has two functions

Answer 9

• it is present in the subendothelilal connective tissue and it assist in platelet plug formation by attracting platelets to the site of the vessel damage
• it also circulates the blood bound to factor VIII, stabilising and delaying the degradation of factor VIII (clotting factor)

Question 10

Bleeding time

Answer 10

measure of platelet function

Question 11

APTT

Answer 11

assesses the intrinsic pathway of coagulation, of which VIII is a component

Question 12

platelet count in Von Willebrand disease

Answer 12

normal, as are PT and INR

Question 13

PT and INR

Answer 13

measures of the extrinsic pathway

Question 14

Haemophilia A

Answer 14

deficiency or reduced activity of factor VIII

- insufficient fibrin is produced in haemostats

Question 15

which of the following is a co-factor requited for effective clotting

calcium
copper
iodine
iron
magnesium

Answer 15

calcium

Question 16

what substances are released by and activate platelets

Answer 16

ADP and thromboxane A2 are released by activated platelets and cause further platelet activation

Question 17

which substance doesn’t circulate within the blood

Answer 17

fibrin

Question 18

which molecule requires Vitamin K for its synthesis

Answer 18

prothrombin

Question 19

which of the following is NOT seen in significant pulmonary embolism

alveolar hypertension
impaired gas exchange
increased pulmonary vascular resistance
right ventricular dilatation
systemic hypertension

Answer 19

systemic hypertension

Question 20

why is systemic hypertension NOT seen in significant PE

Answer 20

systemic hypotension occurs as the vascular obstruction diminishes the venous return to the left ventricle, thereby decreasing its output and causing hypotension

Question 21

if an embolus found in the right leg has cholesterol clefts which other condition is the pt likely to have

Answer 21

abdominal aortic aneurysm

• contains cholesterol indicating it is likely to have come from an atherosclerotic plaque
• atrial fib and left ventricular aneurysm can result in cardiac thrombi and embolism BUT WONT CONTAIN CHOLESTEROL CRYSTALS.

Question 22

which is the most common inherited thrombophilia in caucasians

Answer 22

factor V leidon

Question 23

line of Zahn are only seen in

Answer 23

arterial thrombi

Question 24

a 74 yr old man present with a painful, pale and cold right food. No pedal pulse can be felt. The signs and symptoms are thought to be due to a thromboembolism. From where is the thromboembolism least likely to have arisen?

AAA
Aortic valve
Femoral vein
Left atrium
Left ventricle

Answer 24

femoral vein