Which of the following processes are involved in respiration? (Select all that apply. )

A) Ventilation
B) Diffusion
C) Oximetry
D) Perfusion

Ventilation

The process of supplying fresh air to an environment or removing stale air from it to maintain a healthy atmosphere.

Diffusion

The passive movement of molecules or particles from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Oximetry

A non-invasive method used to monitor the oxygen saturation of a person's blood, often through a device attached to a finger.