Blood clotting

Question 1

What are the main proteins in the plasma of blood?

Answer 1

1. Albumin = produced by liver and maintain osmotic pressure in the blood by drawing water from tissues
2. Globulins = alpha and beta transport lipids and fat-soluble vitamins and gamma antibodies produced by B cells
3. Fibrinogen = clotting factor produced in liver

Question 2

Where are platelets stored?

Answer 2

Red pulp of the spleen

Question 3

How are platelets made?

Answer 3

They are made from Megakaryocytes, giant polyploid cells. Platelets are fragments that peel off of those giant cells

Question 4

What are three mechanisms implemented by the body to minimise blood loss from a wound?

Answer 4

1. Vasoconstriction
2. Formation of a sticky platelet plug
3. Production of a web of insoluble fibrin proteins around and within the platelet plug

Question 5

What protein do the activated platelets convert?

Answer 5

The granules release from activated platelets convert fibrinogen into fibrin

Question 6

What is a great activator of platelets?

Answer 6

Collagen which is exposed to blood when a wound destroys the endothelial layer that separates blood vessels from connective tissue where the collagen is found

Question 7

What is the role of Von Willebrand’s factor?

Answer 7

VWF is situated on the collagen fibres and anchors platelets to them making sure the new forming platelet plug doesn’t wash away.

Question 8

What do platelets release to attract more platelet to the site?

Answer 8

ADP and Thrombaxane A2

Question 9

Explain enzyme cascade of intrinsic pathway of coagulation

Answer 9

Collagen activates XII > XI > IX > VIII&raquo_space;»»> X which converts Protothrombin to thrombin which in turn converts Fibrinogen to Fibrin

Question 10

Explain enzyme cascade of extrinsic pathway of coagulation

Answer 10

Tissue thromboplastin > VII&raquo_space;»»»»> X which converts Protothrombin to thrombin which in turn converts Fibrinogen to Fibrin