Infarction

Question 1

What is infarction?

Answer 1

Necrosis due to hypoxia caused by circulatory disorders (e.g. thrombosis, embolism, prolonged spasm).

Infarction is the extreme result of ischemia.

Question 2

What are some factors that can predispose an organ to infarction?

Answer 2

Usually occurs in organs that have few anastomoses or that are not well developed (brain tissue esp. sensitive).

Low blood pressure can also be an important factor.

The suddenness of the ischemic process is also important (does the organ have time to form collaterative circulation).

Question 3

Into what types can infarction be classified to by its exterior qualities?

Answer 3

-White or ischemic infarction
-Red or hemorrhagic infarction
-White or ischemic infarction with hemorrhagic borders
-Venous infarction

Question 4

What is the shape of infarction?

Answer 4

Usually triange shaped (pointed end towards the obstructed artery) - in kidneys, spleen, lungs

In some tissues the infarction will be irregular - in myocardium, intestines, brain

Question 5

Into what stages can the development of infarction be divided to?

Answer 5

Ischemic (pre-necrotic) and necrotic stage.
Macroscopic characteristics will only be seen after necrotic stage.

Question 6

What is white or ischemic infarction and where does it occur?

Answer 6

-Yellowish white colour (does not contain blood)
-Mostly in kidneys and spleen

Question 7

What is red or hemorrhagic infarction and where does it occur?

Answer 7

-Necrotic region is saturated by blood from surrounding veins due to venous congestion
-Red with well-defined borders
-Occurs in lungs, intestines and spleen

Question 8

Where does white infarction with a hemorrhagic borders happen?

Answer 8

Kidneys and myocardium

Question 9

What is venous infarction?

Answer 9

-Occurs when vein is compressed fast or because of thrombosis
-Can occur because of uterus and bowel rotation
-Resembles hemorrhagic infarction but has an ischemic zone