Cell Injury and Adaptation Questions & Notes for NExT Exam – Pathology

Cell Injury and Adaptation Questions & Notes

As like every chapter this chapter’s cell injury and adaptation will also have its own notes and practice questions. There are 19 practice questions are added so far.


When a cell is exposed to a range of stimuli as well as unfavourable environmental changes, two primary processes occurs, cell injury and adaptation.

Cell injury:

  • Disease that occurs at a microscopic level in the human body
  • Because tissues are not working normally
  • Because of cell damage or inability to operate properly.

Cellular adaptation:

Cellular adaption refers to a cell’s capacity to respond to a variety of stimuli as well as unfavourable environmental changes.

  • Atrophy,
  • Hypertrophy,
  • Hyperplasia,
  • Dysplasia, and
  • Metaplasia

Important things in Cell Injury and Adaptation:


It is the morphological manifestation of end result of irreversible cell injury.

S. NoTypes of NecrosisCauseMorphology


Coagulative necrosis

Ischaemiacellular outline preserved


Liquefactive necrosis

Infection and ischaemia of CNStissue turns into a viscous liquid
3Caseous necrosisT.B and systemic fungal infectioncombination of coagulative and liquefactive necrosis(cheese-like)


Fat necrosis

Lipolysischalky white area
5Fibrinoid necrosisAg-Ab complex depositionthe homogeneous pink stained area

Apart from this there is another type of necrosis also called gangrenous necrosis,which is nothing but massive necrosis with superadded purefaction.

Gangenous necrosis is of 2 types:

  1. Dry gangrene – due to arterial occlusion
  2. Wet gangrene – due to venous occlusion


Regulated mechanism of cell death that eliminate irreversibly damaged and unwanted cell,with least damage to the host.

Causes may be,

  1. Physiologic [embryogenesis] or
  2. Pathologic[viral infection]

Mechanism of Apoptosis

2 phases:

  • Initiation phase

Intrinsic pathway-signal for apoptosis comes from inside cell itself

Extrinsic pathway-signal comes from outside cell

  • Execution phase
Initiation phases is characterised by activation of caspases
execution phaeses is associated with cleavage of cellular elements

For animatic visual

3. Calcification

It is nothing but abnormal tissue deposition of calcium salts along with smaller amounts of Fe,Mg….

2 types:

  1. Dystrophic calcification- occurs in dead and degenerated tissues
  2. Metastatic calcification-occurs in nirmal tissues



It is a type of cell death that is morphologically necrosis but mechanically apoptosis.it is caspase-independent


They are concentric layers of calcium deposition mainly in necrotic areas, seen associated with papillary structures.

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