Necrosis vs. Apoptosis

Introduction

• Cellular Death: Essential for growth and survival of multicellular organisms.
• Types of Cell Death:
  • Necrosis: Death due to harmful environmental exposure or injury.
  • Apoptosis: Pre-planned, regulated process of cell disintegration.

What is Necrosis?

• Results from exposure to extreme conditions different from normal.
• Causes damage to internal cellular environment.
• Leads to rapid cell and tissue damage.
• Cells cannot maintain balance, leading to dysfunction and death.

What is Apoptosis?

• Pre-planned, normal process of cell death.
• Cells actively participate in their own death as part of turnover.
• Maintains balance in cellular multiplication.
• Essential for body functioning; prevents tumor or cancer formation.

Differences in Cause and Presentation

Necrosis

• Pathological: Occurs due to toxins, extreme conditions like heat, and low oxygen.
• Damage: Cell wall/membrane damage, inflammation, tissue damage, cellular debris.

Apoptosis

• Physiological: Necessary for cell number balance.
• Consequence: Prevents tumors, cancer, and diseases like AIDS, heart, and liver diseases if apoptosis is unregulated.

Differences in Structural Changes

Necrosis

• Loss of cell wall integrity.
• Swelling and disintegration of cellular contents.

Apoptosis

• No disintegration of cell membrane.
• Formation of apoptotic bodies (condensed bodies).
• Recognized and destroyed by immune cells.
• No inflammatory reaction due to coordinated process.

Differences in Biochemical Reactions

Necrosis

• Passive Process: No energy required, occurs randomly.

Apoptosis

• Active Process: Requires energy.
• Organized process involving enzymes and agents.

Summary

• Both apoptosis and necrosis result in cell death but differ in processes.
• Necrosis: Untimely death due to uncontrolled external factors; pathological.
• Apoptosis: Pre-defined cell suicide for body function maintenance; physiological.
• Apoptosis is essential, while necrosis results from inflammation and damage.