Thrombosis, Embolism, Ischaemia & Infarction L6

Question 1

What 4 solid cells make up the blood?

Answer 1

Oxygen carrying red blood cells
Infection fighting
Inflammatory WBC
Clot forming platelets

Question 2

What is the term for describing the blood fluid?

Answer 2

Plasma

Question 3

Why is it surprising the blood doesn’t clot all the time?

Answer 3

All the cells and proteins are present in the blood that form a clot

Question 4

What two factors mean that clots are rare?

Answer 4

Laminar flow
Endothelial cells (non sticky)

Question 5

Describe laminar flow

Answer 5

Cells travel in the centre of arterial vessels
and don’t touch the sides

Question 6

Are endothelial cells sticky when healthy?

Answer 6

NO

Question 7

Define thrombosis

Answer 7

The formation of a solid mass from blood constituents in an intact vessel in a living person

Question 8

What’s the 1st stage of thrombosis formation

Answer 8

Platelet aggregation

Question 9

What happens when platelets aggregate? and then what happens?

Answer 9

They release chemicals, causes platelets to stick to each other and this starts off the cascade of clotting proteins in the blood

Question 10

What do both the processes involve?

Answer 10

Positive feedback loop

Question 11

What large protein is formed when the clotting cascade starts? And what does it do?

Answer 11

Fibrin
which makes a mesh in which red blood cells can become
entrapped.

Question 12

What is the precursor of Fibrin and what is it made up of ?

Answer 12

fibrinogen, is a fibrous protein made up of three pairs of polypeptide

Question 13

What 3 factors make up/cause thrombosis?

Answer 13

1) Change in vessel wall
2) Change in blood flow
3) Change in blood constituents

Question 14

What vessels are prone to thrombosis?

Answer 14

Arteries

Question 15

Give an example of something that causes thrombosis

Answer 15

Endothelial cell injury by cigarette smoking causing
Endothelial cell injury (change in vessel wall and change in blood flow over the injured/absent cells)

Question 16

What is the usual thrombosis seen in hospital patients

Answer 16

Deep Vein Thrombosis

Question 17

Treatment for high thrombosis?

Answer 17

Early mobilisation after operation, low dose subcutaneous heparin

Question 18

Define embolism?

Answer 18

Process of a solid mass in the blood being carried through the circulation to a place where it gets stuck and blocks the vessel

Question 19

The solid mass is usually a …

Answer 19

Thrombus

Question 20

Give a hospital example of thrombosis and embolism?

Answer 20

Deep vein thrombosis of leg veins
Which breaks off and embolises through the large veins and
Right side of the heart to the lungs

Question 21

What are the 5 less common causes of embolus?

Answer 21

Air
Cholesterol crystals
Tumour
Amniotic fluid
Fat

Question 22

True or false - aspirin causes platelet aggregation?

Answer 22

True

Question 23

If an embolus enters the venous system it will travel to the ______ , through the _____ side of the heart and will lodge somewhere in the ________

Answer 23

vena cava
right
pulmonary arteries

Question 24

Why do the lungs act as a filter for venous emboli?

Answer 24

An embolus cant get through the arterial circulation because…
Blood vessels in the lung split down to capillary size so they act as a filter

Question 25

Why is it bad if an embolus enters the arterial system?

Answer 25

It can travel anywhere downstream of its entry point

Question 26

Mural Thrombus (READ)

Answer 26

e.g. a mural thrombus overlying a myocardial infarct
in the left ventricle can go anywhere is the systemic
circulation, cholesterol crystals from an atheromatous plaque
in the descending aorta can go to any of the lower limb and
renal arteries.

Question 27

Define ischaemia

Answer 27

Reduction in blood flow to a tissue without any other implications

Question 28

Define infarction

Answer 28

Reduction in blood flow to a tissue that is so reduced that it cannot even support mere maintance of the cells of the tissue so they die

Question 29

Infarction is usually what kind of event? Caused by?

Answer 29

Macroscopic
Thrombosis of an artery

Question 30

A thrombus in the left anterior descending coronary artery causes infarction of ??

Answer 30

Anterior wall of left ventricle

Question 31

T or F Most organs in the human body have only a single artery supplying them?

Answer 31

True (end arterial supply)

Question 32

True or False organs with one blood flow are very susceptible to infarction?

Answer 32

True

Question 33

Some organs have dual arterial supply what’s the benefit of this?

Answer 33

Less susceptible to infarction

Question 34

Give examples of dual supply organs

Answer 34

Liver - with portal venous and hepatic artery supplies
Lung - with pulmonary venous and bronchial artery
supplies
Brain around the circle of Willis with multiple
arterial supplies