PBL 8 - clotting and thrombosis

Question 1

what is thrombosis?

Answer 1

the formation of a solid or semi-solid mass from the constituents of the blood while moving within the vascular system during life

Question 2

what is an embolism?

Answer 2

the transport of abnormal material (solid, liquid, gas) by the blood stream and its impacting in a blood vessel

Question 3

what is a clot?

Answer 3

a solid mass formed from the constituents of blood that no longer moves

Question 4

what are lines of Zahn?

Answer 4

get them in thrombus

= alternating layers of platelet-rick thrombus and erythrocyte-rich thrombus (dark pink and pale pink lines) — helps us tell the difference between a thrombus and clot

Question 5

what are triggers for disseminated intravascular coagulation?

Answer 5

infections, septicaemia, burns, and neoplasms (+ covid-19)

Question 6

what is Virchow’s triad?

Answer 6

1. abnormalities of the vessel wall
2. abnormalities of blood flow
3. abnormalities of the blood’s constituents

Question 7

how can rheumatic endocarditis lead to thrombosis?

Answer 7

rheumatic fever causes inflammation in all 3 layers of the heart wall — inflammation (particularly in valves) — platelet aggregates — thrombosis

Question 8

how can MI lead to thrombosis?

Answer 8

• MI causes scarring and sites of immobility — can lead to thrombosis in lumen
• immobility leads to an accumulation of the activated factors
• breakdown of dead muscle due to infarction also contributes to thrombosis in adjacent lumen

Question 9

what can lead to increased viscosity?

Answer 9

• polycythaemia
• dehydration
• chronic hypoxia
• polycythaemia rubra vera

Question 10

what is polycythaemia rubra vera?

Answer 10

disease of blood — abnormal proliferation of the precursors of cells — increased viscosity due to increased Hb

Question 11

how can multiple myeloma lead to reduced blood flow?

Answer 11

multiple myeloma — makes you hyperproteinaemic — unregulated growth of plasma cells — generate immunoglobins in vast excess = reduced blood flow

Question 12

what is Caisson disease?

Answer 12

divers come up too quickly from deep pressures. N2 is more easily dissolved in fat in v high pressures — once the pressure reduces as they come up, bubbles of N2 form in blood stream and cause extreme pain aka. ‘the bends’ = when the N2 comes out of the fat within the long bones

Question 13

what are some pathological consequences of pulmonary thromboembolism?

Answer 13

• nothing
• pain, often pleuritic (cause ishcameia in lung peripherally_
• haemoptysis (sufficient damage to lung periphery — leakage of blood from infarcted lung tissue into air spaces)
• breathlessness
• right heart failure
• pulmonary hypertension
• sudden death