Thrombosis & Embolism 1

Question 1

Describe normal blood flow.

Answer 1

Normal blood flow is described as laminar, smooth, and ordered, with cells held in the center of the flowing blood surrounded by plasma and in contact with the endothelial surface.

Question 2

Define vascular compliance.

Answer 2

Vascular compliance refers to the ability of blood vessels to expand and contract in response to changes in pressure, volume, or flow.

Question 3

How does vessel compliance vary among different types of vessels?

Answer 3

Muscular arteries are less compliant than elastic arteries, which are in turn less compliant than veins.

Question 4

Do you know two types of abnormal blood flow?

Answer 4

Stasis, which is stagnation of flow, and turbulent flow, which is forceful and unpredictable.

Question 5

Describe Virchow’s Triad.

Answer 5

Virchow’s Triad consists of three components: changes in the blood vessel wall, changes in the blood constituents, and changes in the pattern of blood flow, which collectively contribute to thrombosis.

Question 6

Define Vascular Steal syndrome.

Answer 6

Vascular Steal syndrome, such as Subclavian Steal Syndrome, occurs when a vascular network diverts blood from another region within an organ that is already maximally dilated due to stenosing lesions.

Question 7

Describe thrombosis and thrombus formation.

Answer 7

Thrombosis is the formation of a solid mass from blood constituents within the vascular system, while a thrombus is the solid mass formed during this process.

Question 8

Differentiate between clot and thrombus.

Answer 8

A clot is solid blood that does not meet the criteria of a thrombus. For example, blood solidifying in a tube outside the body or post-mortem clots are not considered thrombi.

Question 9

Explain the role of Virchow’s triad in thrombosis pathogenesis.

Answer 9

Virchow’s triad consists of endothelial injury, stasis or turbulent blood flow, and hypercoagulability, all contributing to the formation of thrombi.

Question 10

Illustrate the impact of an atheromatous plaque on thrombosis development.

Answer 10

An atheromatous plaque can lead to turbulent blood flow, endothelial damage, and the adherence of blood elements, ultimately resulting in thrombus formation.

Question 11

Describe the components of a normal artery.

Answer 11

A normal artery consists of an endothelial lining, smooth muscle layer (media), connective tissue layer (adventitia), and elastic laminae separating these layers.

Question 12

Explain the difference between a normal artery and an atheromatous coronary artery.

Answer 12

A normal artery has a large lumen and intact layers, while an atheromatous coronary artery has a reduced lumen due to a plaque that causes destruction and calcification.

Question 13

Describe the process of thrombus formation in an atherous coronary artery.

Answer 13

Atheroma in the artery causes turbulent blood flow, leading to fibrin deposition, platelet clamping, collagen exposure, platelet adhesion, fibrin meshwork formation, and red blood cell entrapment.

Question 14

Define Lines of Zahn in the context of thrombus formation.

Answer 14

Lines of Zahn refer to alternating bands of red cells and platelets seen in appearance within a thrombus.

Question 15

How does hypercholesterolemia relate to atheroma and thrombosis?

Answer 15

Hypercholesterolemia is a significant risk factor for atheroma, which can lead to arterial thrombosis due to the deposition of platelets and fibrin on the atheromatous plaque.

Question 16

Describe the relationship between atheroma and Virchow’s Triad.

Answer 16

Atheroma, by changing blood constituents like cholesterol, contributes to Virchow’s Triad, which includes factors predisposing to thrombosis.

Question 17

Do atheromatous changes only affect coronary arteries?

Answer 17

No, atheromatous changes can also occur in the heart itself, leading to thrombus formation within the heart.

Question 18

Describe the impact of a previous myocardial infarct on thrombus formation in the heart.

Answer 18

A previous myocardial infarct can cause thinning of the heart wall, leading to dilatation of the ventricle and subsequent thrombus formation on the inner surface.

Question 19

Describe the process of mural thrombus formation as explained in the content.

Answer 19

Mural thrombus forms when there are changes in blood constituents, such as hyperviscosity, hypoxia, or a hypercoagulable state, leading to a predisposition to thrombosis.

Question 20

Define Virchow’s triad and provide examples of its components mentioned in the content.

Answer 20

Virchow’s triad refers to the three factors contributing to thrombosis: changes in the vessel wall, blood constituents, and blood flow. Examples include hyperviscosity, stasis (e.g., economy class syndrome), and turbulent flow (e.g., atheromatous plaque).

Question 21

How does chronic hypoxia contribute to changes in blood constituents according to the content?

Answer 21

Chronic hypoxia can lead to secondary polycythaemia, which is an increase in the number of red blood cells, causing a change in blood constituents.

Question 22

Describe the consequences of thrombosis as discussed in the content.

Answer 22

The consequences of thrombosis depend on factors like the site and extent of the thrombus, whether there is partial or complete occlusion of the vessel, and the presence of collateral circulation that could bypass the thrombosed vessel.

Question 23

Do you know what Lines of Zahn refer to in the context of thrombosis?

Answer 23

Lines of Zahn are alternating layers of platelets and fibrin seen in thrombi, giving them a striped appearance, often found in arterial thrombi.

Question 24

Explain the relationship between atheromatous plaque and thrombus formation in the content.

Answer 24

Thrombus can form on atheromatous plaques, leading to insufficient blood and oxygen supply to tissues, such as in the case of myocardial infarction.

Question 25

Describe a common clinical scenario mentioned in the content where thrombosis occurs in the lower limb veins.

Answer 25

A common clinical scenario discussed is deep vein thrombosis (DVT), where the veins of the lower limb become thrombosed, potentially leading to serious complications.

Question 26

How can stasis of blood flow contribute to thrombus formation according to the content?

Answer 26

Stasis of blood flow, such as in situations like prolonged bed rest or long-haul flights, can lead to the formation of thrombi due to the lack of normal blood movement and increased risk of clotting.

Question 27

Describe the best outcome of thrombosis.

Answer 27

Complete resolution of the thrombus with restoration of blood flow and no abnormality in the organ being fed by the vessel.

Question 28

What intervention may be needed for thrombosis if spontaneous resolution does not occur?

Answer 28

Fibrinolytic or thrombolytic agents to dissolve the thrombus.

Question 29

How does the process of organisation of a thrombus occur?

Answer 29

Thrombus shrinks, contracts, gets digested, and new vessel formation happens with granulation tissue and recanalisation.

Question 30

Define thrombolysis in the context of thrombosis treatment.

Answer 30

The process of breaking down the fibrin in a thrombus using fibrinolytic or thrombolytic agents.

Question 31

What are some unfavourable outcomes of thrombosis mentioned in the content?

Answer 31

Death of the person due to the thrombus or propagation leading to embolism.

Question 32

Describe the process of recanalisation in the context of thrombosis.

Answer 32

Restoration of blood flow in the vessel after organisation of the thrombus, often involving the growth of new capillaries into the area.