Inspiration

Expiration

Breathing In

Breathing Out

External Respiration

Internal Respiration

Exchange of gases between air and blood

Exchange of gases between blood and tissue fluid

- warms air

-cleanses air-coarse

-humidifies air

2 nasal cavities

communicates with sinuses

lined by mucous membrane

-bony ridges increase surface area

connects nasal and oral cavities to larynx

where oral cavity opens

uvula projects into oropharynx

-opens into larynx

-tonsils form a protective ring

-esophagus is normally closed

-passageway for air between pharynx and trachea

Vocal Folds

-folds of mucosa

-supported by elastic ligaments

-vibrates during exhalation

-pitch controlled by tension

-loudness controlled by ampitude of vibration

Connects larynx with primary bronchi

supported by c shaped cartilage rings

-keeps trachea patent yet flexible

Lined with Epithelium

Right and Left primary bronchi

-resemble trachea in structure

Branch to Secondary Bronchi

-leads to bronchioles

As airways get smaller walls become thinner

-lacks cartilage rings

Alveoli

surrounded by blood capillaries

gas exchange occurs across alveolar wall and capillary wall

-oxygen diffuses into blood

-carbon dioxide diffuses into alveoli

Stay open to receive air

-surface tension has tendency to make them collapse

divided into lobes

-right lung has 3

-left lung has 2

lobe/ into lobules

double layered

visceral pleura on lung surfaces

parietal pleura on walls of thoratic cavity

surface tension holds the 2 pleural layers together

amount of air moving in and out with each breathe

average is 500ml

maximum volume moved in and moved out in a breathe

illness can affect vital capacity

forced inhalation

amount of air brough in above tidal volume

normally about 2,900ml

forced exhalation

air exhaled beyond tidal volume

normally about 1,400ml

Amount of air always remaining in lungs

normally about 1,000ml

not useful for gas exchange