Respiration

(1) Pulmonary Respiration = ventilation (breathing) and the exchange of gases (O₂ and CO₂) in the lungs

(2) Cellular Respiration = O₂ utilisation and CO₂ production by the tissues

(1) gas exchange between environment and the body

(2) regulation of acid-base balance during exercise

• Provided an airway for respiration
• Moistens and warms entering air
• Filters inspired air

• Connects nasal cavity and mouth to the larynx
• Common pathway for food and air

• Provide opening for air and food
• Voice production
• The epiglottis - prevents food going into the trachea

• Comprises of rings of cartilage
• Descends from the larynx and divides into two primary bronchi

• At the end of the bronchioles
• Provide a thin barrier and very large surface area for gas exchange by diffusion

• Components: nose, pharynx, larynx, trachea, bronchiole tree
• Conducts air to the 'respiratory zone'
• Humidifies, warms and filters air

• Components: respiratory bronchioles, alveoli ducts, alveoli
• Exchange of gases between air and blood

Oxygen passively diffusing from air to cells

From contraction of the diaphragm, the intrapleural pressure falls, allowing air to flow into lungs

• Stretched lung tissue recoils, releasing air passively (during quiet breathing)
• Changes in volume cause changes in pressure which allows for the flow of gases

• Change in volume causes change in pressure.
• Increase volume = decreased pressure
• Decreased volume = increased pressure

Total pressure of a gass mixture = sum of pressures each gas would exert independently.

• Increased concentration of hydrogen ions
• Decreased pH