Question

Which of the statement is false for venous thrombi ?

• A. Ischaemic necrosis of the deprived part
• B. Poor wound healing
• C. Skin ulcer
• D. Oedema of area drained

Hint:

Arterial Block = Ischemia, Pallor (pale), Cold, Necrosis/Infarct (Tissue starves of oxygen).
Venous Block = Congestion, Oedema (swelling), Red/Blue, Ulcers (Waste products pool up).

Answer 1

The Correct Option is A

Step 1: Concept:
This question evaluates the pathophysiological differences between arterial thrombosis (blockage of blood flowing to a tissue) and venous thrombosis (blockage of blood draining away from a tissue).

Step 2: Step-by-step Explanation:

• A venous thrombus (like a DVT in the leg) blocks the return of deoxygenated blood back to the heart. This creates a massive "traffic jam" or back-pressure in the venous system.

• This back-pressure forces plasma out of the capillaries into the surrounding tissues, leading to severe Oedema (swelling) of the area drained (Option D is true).

• Because the venous blood is stagnating and pooling (venous stasis), tissues struggle to clear metabolic waste, leading to chronically Poor wound healing (Option B is true) and the eventual breakdown of tissue forming Skin ulcers (stasis ulcers) (Option C is true).

• Ischaemic necrosis (infarction) (Option A) happens when a tissue is completely starved of fresh, oxygenated arterial blood. This is the classic hallmark of an arterial thrombus (e.g., causing a heart attack or stroke). While severe venous blockages can occasionally lead to gangrene (phlegmasia cerulea dolens), ischemic necrosis is fundamentally defined as an arterial failure issue, making it the textbook "false" statement for venous thrombi.

Step 3: Final Answer:
Ischaemic necrosis is false for venous thrombi; it is an arterial characteristic.