by / Thursday, 24 February 2011 / Published in Pathology

Understanding how and WHY cellular injury occurs will help you achieve that “aha” moment, whereby you will understand how to answer thousands of questions based simply on the understanding of these two forms of irriversible cellular injury.



What’s going on?

1. APOPTOSIS – programmed cellular death.

– membrane dissolves first (ie from the outside in)

– the nucleus has the information for apoptosis, thus it only makes sense that it will be the last thing to be destroyed.

– questions asking you what is first thing to go?  look for the word ‘periphery’ because that is the most common part of knowing programmed cellular death!

– is not an inflammatory reaction because it is programmed to die, thus no disruption/inflammatory activity

Pyknosis – blebs of the nucleus

Karyorhexxis – chunking of the nucleus

Karyolysis – dissolving of the nucleus

These are terms linked to apoptosis


2. NECROSIS – is non-programmed cellular death

– nucleus is the first thing that is dissolves/killed

– not a programmed activity thus it stimulates the inflammatory mechanism

– uses pyknosis, karyohexxis, and karyolysis


Use these components to decipher between many different forms of pathology.. Ex. if inflammtion is present, we know it is necrosis…. if a disease involves inflammation, we know it is a non-programmed event.  Seeing this concept will allow you to answer alot of questions with little information!


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