Respiratory System (3)

Main functions of the respiratory system

exchange gases between the atmosphere and blood, regulate pH, body temperature and hydration status

Ventilation

mechanical events of breathing

Respiration

transport of O2 to tissues

External respiration

exchange of O2 and CO2 between the lungs and blood

Internal respiration

exchange of O2 and CO2 between blood vessels and tissues

Cellular respiration

consumes O2 for energy, produces CO2

Conducting zone

zone that air moves through, made of cartilage

Respiratory zone

site of gas exchange

Inspiration (active)

air flows into lungs as pressure goes down

Expiration (passive)

air flows out of lungs as pressure goes up

O2-Hb dissociation curve

as O2 pressure goes down, O2 saturation in Hb goes down

Shift curve to the right

increases in temperature, drop in pH

Shift curve to the left

decreases in temperature, increase in pH

Ventilation-perfusion matching

amount of gas and blood flow reaching alveoli should be matched for efficient gas exchange

Pulmonary arteries

deliver deoxygenated blood to lungs for gas exchange

Pulmonary capillaries

site of gas exchange between blood and lungs

Pulmonary veins

carry oxygenated blood from respiratory zones to left atrium

CO2 transport

70% is transported as bicarbonate ions in plasma - buffer to control pH

P CO2 levels rise

chemoreceptors send signals to increase depth and rate of breathing

P O2 levels drop

chemoreceptors send signals to increase ventilation