Respiratory system and breathing muscles

Main breathing muscles and terms

What is the full sequence of air entering the body?

Nose/mouth to pharynx to larynx to trachea to bronchi to bronchioles to alveoli.

Where does gas exchange happen?

Alveoli, oxygen passes into blood, CO2 passes out.

What is the diaphragm?

Main breathing muscle, contracts and flattens to inhale, relaxes and arches to exhale.

What is tidal volume?

Amount of air breathed in or out in one normal breath which is approximately 500ml.

What is vital capacity?

The maximum amount of air exhaled after maximum inhalation.

What happens to breathing depth during exercise?

Increases, larger volumes of air is moved with each breath to meet oxygen demand.

Normal adult breathing rate at rest?

12 to 20 breaths per minute.

Nose and mouth

Air enters, nose filters, warms and humidifies air. Part of the conducting zone.

Pharynx

Throat, passage from air and food. Part of the conducting zone.

Larynx

Voice box, contains vocal cords. Part of the conducting zone.

Trachea

Windpipe, carries air down to lungs. Part of the conducting zone.

Bronchi

Two branches, one going to each lung. Part of the respiratory zone.

Bronchioles

Smaller branches inside each lung. Part of the respiratory zone.

Alveoli

Tiny air sacs where O2 and CO2 exchange happens. Part of the respiratory zone.

What happens to breathing rate during exercise?

Increases, more oxygen needed and more CO2 to remove.