1. Infarction occurs when there is a decrease in blood supply to an organ or tissue, causing localized ischemic necrosis. This can be caused by thrombi, emboli, vasospasm, expansion of atheroma, extrinsic vessel compression, vessel twisting, or traumatic vessel rupture. 2. There are three main types of infarction: red (hemorrhagic), white (anemic), and septic. Factors like vulnerability to hypoxia, oxygen content of blood, and blood supply nature influence whether infarction occurs. 3. Examples of infarctions include myocardial, pulmonary, and cerebral. Myocardial infarction due to coronary artery blockage can be fatal, while pulmonary infarction is usually

1. PAT-201

2. INFARCTION
INFARCTION : The formation of localized area of
ischemic necrosis within tissue or
organ due to decrease blood supply .
( hypoperfusion )

3. INFARCTION
Hypoperfusion caused by ( TEVACTR ) :
* Thrombi or Emboli .
* local Vasospasm (vasoconstriction).
* Expansion of Atheroma .
* Extrinsic Compression of a vessels.
* Vessel Twisting .
* Traumatic vessel Rupture .

4. INFARCTION
• THROMBI :-
Is a blood clot in
vascular system .
• EMBOLI
Is unattached mass that travels trough
blood stream and is capable clogging
arterial capillary.

5. INFARCTION
Local vasospasm : is condition in which an arterial spasm leads
to vasoconstriction. This can lead to tissue ischemia and tissue
death (necrosis).

6. INFARCTION
• Expansion of atheroma :-
( atheroma: is accumulation of material in the inner layer
of the wall of an artery ) .

7. INFARCTION
• Extrinsic compression of a
vessels :-
• Vessel rupture
: ( trauma )

8. INFARCTION
• Vessel twisting :-
(tortous BV)

9. INFARCTION
Types of infarction :
* Red infarction (hemorrhagic )infarct .
* White (anemic) infarct .
* septic infarct.

10. A-Red (hemorrhagic) infarcts occur :
1) with venous occlusions
(such as in ovarian & testis )
2)in loose tissue ( e.g lung ) which
allow blood to collect
in the infarcted zone .
Lung infarction

11. A-Red (hemorrhagic) infarcts occur :
3) in tissues that were
previously congested
because of sluggish venous
outflow .
4) in tissue with dual
circulation (such as lung ,
small intestine ) .
Small intestine infarction

12. B-White (anemic) infarct occur:
• with arterial occlusion in solid organ with end-
arterial circulation (such as heart , spleen &
kidney )
Renal infarction

13. C- Septic infarct :
o Bacteria containing
emboli .
o may from abscess
and pus .

14. INFARCTION
Factors that influence development of an
infarct :.
Rate of development of occlusion
Vulnerability to hypoxia
Oxygen content of blood

15. INFARCTION
Nature of the vascular supply :
(Double or single blood supply )
oThe availability of an alternative blood supply
is the most important factor in determining
whether occlusion of a vessel will cause damage.

16. INFARCTION
Rate of development of occlusion :
o
Slowly developing occlusions are less likely to cause
infarction because they provide time for the development of
alternative perfusion pathways.
for example there are three major coronary arteries in the
heart. If one of the coronaries is only slowly occluded, flow within this
collateral circulation may increase sufficiently prevent infarction, even
though the major coronary artery is eventually occluded .

17. INFARCTION
Vulnerability to hypoxia :
The susceptibility of a tissue to hypoxia influences the
likelihood of infarction.
For example:
Neurons : undergo irreversible damage when deprived of their
blood supply for only 3 to 4 minutes
Myocardial cells, although hardier than neurons, are also quite
sensitive and die after only 20 to 30 minutes of ischemia
In contrast, fibroblasts within myocardium remain viable even after
many hours of ischemia

18. INFARCTION
Oxygen content of blood :
o
The partial pressure of oxygen in blood also determines
the outcome of vascular occlusion.
o Partial flow obstruction of a small vessel in an anemic or
cyanotic patient might lead to tissue infarction.

19. INFARCTION
• location type outcome
1 Myocardial infarction pale Frequently lethal
2 Pulmonary infarction hemorrhagic
Less
commonly
fatal
3 Cerebral infarction
Hemorrhagic
& pale
Fatal if
massive
• Infarcts of different organs :
*And other organs may infarcted such as kidney, intestine , spleen ,
liver & lower extremities.

20. Myocardial infarction :
Most important consequence of coronary artery
disease.
Patient may die within first few hours of the
onset .
Incidence : Occurs at all age, but more
common in elderly .

21. Myocardial infarction :
Plaque with acute clot in
the coronary artery
blocking blood flow and
oxygen to the heart

22. Pulmonary infarction
 pulmonary infarction ( due to thromboembolus ) .
 GROSS :
 Wedge-shape
Base on the pleura
Hemorrhagic, variable in size
In lower lobes

23. Cerebral infarction
May be :
 Non-occlusive may caused by :
(compression of cerebral arteries from outside during
herniation ) .
 local vascular occlusion
* artery occlusion .
* venous occlusion .

24. Cerebral infarction
pathological changes :
o Anemic and hemorrhagic .
oAffected area: soft and swollen blurrring of
junction between grey & white mater

25. Cerebral infarction
CT SCN ; CEREBRAL
INFARCTION