(relational) Relating to respiration or the organs of respiration; breathing.

(anatomy) The system of organs serving for respiration.

(anatomy) The passages, divided into an upper and a lower part, through which air enters and leaves the body, including the mouth, nose and nasal passages, pharynx, larynx, trachea, bronchi and conducting bronchioles, sometimes further including the respiratory bronchioles, alveolar ducts and alveoli.

(biochemistry) any of several coloured metal-containing protein pigments which combine reversibly with oxygen and which are found in the tissues of vertebrates and invertebrates and whose role is to transport oxygen

Any of the downstream bronchioles that already engage in blood-air gas exchange, in contrast to the upstream conducting-zone bronchioles that merely transport air.

plural of respiratory system

plural of respiratory tract

plural of respiratory pigment

(medicine) A professional medical designation recognized in some jurisdictions, denoting an individual who is fully qualified and licensed to evaluate, treat, and care for patients with breathing or other cardiopulmonary disorders.

plural of respiratory practitioner