Cellular Apoptosis is a programmed cell death mechanism that occurs in multicellular organisms to maintain tissue homeostasis and remove unwanted or damaged cells. It is a controlled and energydependent process, ensuring that cell removal does not trigger inflammation or damage to surrounding tissues.

Key Features of Cellular Apoptosis:

1. Morphological Changes:

Cell Shrinkage: The cell reduces in size, with the cytoplasm condensing.

Chromatin Condensation: The nucleus becomes dense and fragmented.

Membrane Blebbing: The plasma membrane forms protrusions.

Apoptotic Bodies: The cell breaks into small vesicles containing cellular components.



2. Biochemical Events:

Caspase Activation: Proteases (caspases) are activated to degrade cellular proteins.

DNA Fragmentation: Endonucleases cleave DNA into characteristic ladder patterns.

Phosphatidylserine Exposure: The inner leaflet of the cell membrane flips to the outside, signaling macrophages for phagocytosis.



3. Pathways of Apoptosis:

Intrinsic Pathway: Triggered by internal signals such as DNA damage or oxidative stress, involving mitochondrial release of cytochrome c.

Extrinsic Pathway: Initiated by external signals binding to death receptors (e.g., Fas receptor or TNF receptor) on the cell membrane.



4. Physiological Roles:

Development: Shapes organs and eliminates redundant cells during embryogenesis
‪@MedMicro‬