Home

The Alveolus — Gas Exchange

A single air sac, the capillary wrapped around it, and one red blood cell loading oxygen. Move the sliders to see altitude, exercise and emphysema change how much actually gets on board.

1 / 4

Blood leaves this alveolus 97.1% saturated, up from 74.3% on arrival.

Overview

Oxygen crosses a single cell layer from air to blood, then binds hemoglobin inside a passing red blood cell. Cyan particles carry oxygen in; grey particles carry carbon dioxide out. Tap a part — or the model itself — to look closer.

~480Malveoli ~70 m²surface <1stransit

Anatomy

O₂ in CO₂ out

Readout

Alveolar pO₂—

Blood pO₂ in—

Blood pO₂ out—

Sat. in (venous)—

Sat. out (arterial)—

Hemoglobin P50—

Diffusion efficiency—

Conditions

Altitude0 m

Exercise0%

Emphysema0%

O₂–Hemoglobin Curve

Venous (arriving) Arterial (leaving)

—

For health education only. Not a medical diagnosis.