Non-clinical sciences/Pathology · Cell death

Apoptosis

What it means

Programmed cell death — no inflammation. Intrinsic (mitochondrial): stress/DNA damage → cytochrome c → caspase-9 → caspase-3; regulated by Bcl-2 (anti) / Bax (pro). Extrinsic (death-receptor): Fas/TNF → caspase-8 → caspase-3. Apoptotic bodies cleared silently by phagocytes.

Worked example

Apoptosis removes individual cells cleanly (cytochrome c → caspases) without the inflammation that necrosis causes.

In the exam

Cells die individually via caspase activation and are cleared without inflammation, the opposite of the messy membrane rupture of necrosis.

What settles it

Apoptosis = programmed, energy-dependent, no inflammation; necrosis = passive, membrane rupture, inflammation.

Classically confused with

Necrosis patterns

Source: StatPearls — Apoptosis