Haemostasis

Question 1

what is Haemostatsis

Answer 1

Haemostasis is a balance between prevention of excessive bleeding while avoiding too much bloodclotting/thrombosis.

Question 2

Where is most of the blood in the Haemostatsis

Answer 2

Most of the blood is in the vascular system the blood vessels

Question 3

What the parts of Haemostatsis?

Answer 3

1. Vascular system

2.Circulating platelets

3.Coagulation factors

Question 4

What are the two main elements of Haemostasis

Answer 4

Platelets and coagulation factors with their final products, platelet plugand fibrin mesh

Question 5

What happens in the vasoplasm

Answer 5

Cells in the area signal the epithelia cells to secrete endothelia so it binds to the receptor under the smooth muscle activating an intracellular mechanism curing contractions

Question 6

Where is the platelets made and how long does it live for

Answer 6

1. Produced in the bone marrow from megakaryocytes
2. Live for a week
3. Have no DNA

Question 7

How does it go from megakaryocytes to platelets and what happens if there is too many or too little

Answer 7

1. In the bone marrow megakaryocytes release platelets into sinusoidal blood vessels

2.Too many platelets lead to clotting and death
Not enough - bleeding in the brain and die
We need a certain amount

Question 8

What happens in the Platelets plug formation?

Answer 8

1. endoepithial cells produce vonwilebrand which the GP1B protein binds to and also the platelets bind
2. the platelets release ADP and serotonin which will increase the vasospasm and tell more platelets to come which is platelet aggreation

3.Platelets to go injured area it can’t go to healthy place sue to the release of nitric oxide

Question 9

What happens in coagulation?

Answer 9

1. Strengths the plug by making a mesh to seal damaged area

Question 10

What is the structure of the platelets?

Answer 10

1. Glycogen
2. Lyosomes
3. Mitochondrion
4. Plasma membrane
5. Dense granule electron-have some small molecules like ADP and calcium,
6. Alpha granule-have lots of different proteins

Question 11

What are the other functions of platelets?

Answer 11

1. Repair and tissue healing
   2.Can be injected to hair for hair growth transplant however using other platelets requires that right blood type

Question 12

What is coagulation cascade?

Answer 12

A series of enzymatic reactions which act one upon another in a sequence

Question 13

What does Fibrinolysis do?

Answer 13

Breaks down fibrin clot to return to normal state

Question 14

What is enzyme cascade?

Answer 14

1.Plasminogen is activated generating key enzyme plasmin

2.Plasmin dissolves fibrin clots into soluble fragments including D-dimer

3.Binding of plasmin to fibrin localises fibrinolysis to clot itself -dissolves blood

Question 15

Why thrombosis is so important?

Answer 15

Can cause of most cases of heart attack and strokes

Question 16

what is another reason thrombosis occur?

Answer 16

Abnormalities of the vessel wall such as inflammation and direct injury

Question 17

What is the cause of thrombosis?

Answer 17

1.Abnormalities of blood flow (deep veins)
2. smoking and post-part

Question 18

What is Embolism

Answer 18

Embolism is the blockage of a blood vessel

Question 19

what is Extrinsic (Tissue Factor) pathway

Answer 19

extrinsic due to external addition of thromboplastin
2. Tissue factors activates FVII when ca is there leading to generation of factor xa

Question 20

What is Intrinsic pathway

Answer 20

Intrinsic pathway is initiated by contact activation with a foreign surface: glass, kaolin