CVR qs

Question 1

1. What are the two pathways in the cogulation cascade and their differences?

Answer 1

Intrinsic and extrinsic.
Intrinsic- amplifies the cascade, whereas extrinsic intitiates.

Extrinsic- Tissue factor from damaged tissue. 7A-10-10A. 10A converts prothrombin to thrombin. Thrombin converts fibrinogen to fribrin.

Intrisic is the same latter stage but 12-12a 11-11a 10-10a then Xa converts prothrombin to thrombin
= Thrombin converts fibrinogen to fribrin.

Question 2

How is thrombin produced? What does it do

Answer 2

Xa activation by extrinsic or intrinsic causes prothrombin to thrombin reaction

thrombin catalyses fibrinogen to fibrin
thrombin also binds to PAR 1 and PAR4 receptors = +ve feedback, platelets are activated and thrombin is released

Question 3

Give antigens and antibodies for type AB blood and type O?

Answer 3

AB = both A and B antigens and 0 antibodies

Question 4

1. What is the danger to around pregnancy with a Rhesus negative mother and how can this be overcome?

Answer 4

Could have a rhesus positive baby, so she would make anti-D antibodies. This would cause haemolysis in the baby’s blood and potentially kill the child

Question 5

Explain the monocyte production from bone marrow to circulation?

Answer 5

Undifferentiated stem cell - myeloid stem cell- monoblast-monocyte.

Question 6

What occurs due to hypoxia?

Answer 6

Increased breathing

• lung blood vessels constrict
• increased HR
• peripheral vessels dilate
• increased BP in heart = increased CO
• increased heart contractility

Question 7

Mean arterial pressure

Answer 7

MAP = CO X TPR
MAP = 2/3 diastolic + 1/3 systolic

Question 8

Define contractility in the heart?

Answer 8

Force of contraction and change in fibre length-when muscle contracts myofibrils stay the same length but sarcomeres shorten.