inspiratory

1. Of, relating to, or used for the drawing in of air.
2. Intended or used to motivate or inspire: an inspiratory speech.

Of, relating to, or used for the drawing in of air.

Pertaining to or used in the inspiration of air into the lungs.

• i. center — one of the four respiratory centers in the reticular formation of the brainstem.
• i.-inhibitory reflex — see hering–breuer reflexes.
• i. reserve volume — the volume of air which the patient can still inhale after the completion of inhalation of the tidal volume.

The adjective has one meaning:

Meaning #1: pertaining to the drawing in phase respiration
  Pertains to noun: inhalation (meaning #1)