Reversible vs Irreversible Ischemic Cell Injury (2D)

Ischemia

Severity (blood flow loss) 70%

Cell resilience (mitochondrial reserve) 50%

Simulation speed 1.0×

Tissue State

ISCHEMIA — pump failing

Mean ATP level

100%

Mean cell volume

100%

Irreversibly injured

Elapsed time

0.0 s

How it works

This is the 2D companion to the 3D ischemic cell injury simulator, computed independently from the same per-cell ATP budget rather than a flattened render of the 3D scene. Each cell in this flat field tracks:

dATP/dt = -k_isch·(1-r) + k_regen·r·(1-ATP)
k_isch  = (severity / effective resilience) · 0.35
r       = 1 while reperfusing, else 0

The Na⁺/K⁺-ATPase pump needs ATP to keep sodium (and the water that follows it osmotically) out of the cell. Pump activity is a cooperative function of ATP, and cell area (drawn as radius²) grows when the pump can't keep up:

Pump activity P = ATP²
dV/dt = α·(1-P) - β·P·(V-1),  V clamped to [1, 1.6]

This is reversible cell injury — cloudy swelling — as long as it is corrected in time. Each cell also integrates an injury clock while its ATP stays below a critical threshold; once that clock exceeds the cell's own mitochondrial reserve, the permeability transition pore opens, ATP synthesis becomes permanently impossible, and the cell is marked irreversibly injured — it decays toward necrosis no matter what reperfusion does afterward.

Severity — how completely blood flow (and oxygen) is cut off; higher severity drains ATP faster.
Resilience — the tissue's mitochondrial/glycolytic reserve; higher resilience slows ATP loss and raises the injury-clock threshold before the point of no return.
Start Reperfusion — restores blood flow. Cells still above the point of no return recover fully; cells that already crossed it cannot be saved and continue toward necrosis — the simulator's version of "no-reflow" / reperfusion not helping a dead cell.

Drag the tissue field to pan and scroll to zoom in on individual cells. Clinical relevance: this is the same principle behind the treatment-window urgency in stroke thrombolysis and cardiac reperfusion therapy — tissue salvage is only possible before the point of no return is crossed.

Drag to pan · scroll to zoom

Healthy (high ATP) Reversibly injured (swollen) Irreversible / necrotic