The Structures of the Lungs
that Deliver Oxygen to the Body
By Evelyn Garrity, Nick Suttle, Steven Bu and Eva Lauer
Overall Function
Bring oxygen from atmosphere into bloodstream and to
bring carbon dioxide from the bloodstream into the air
Pathway for Air
nasal cavities (or oral cavity) -> pharynx -> trachea ->
primary bronchi (right & left) -> secondary bronchi ->
tertiary bronchi -> bronchioles -> alveoli (site of gas
exchange)
Main Structures
 Primary bronchi
 Secondary bronchi
 Tertiary bronchi
 Bronchioles
 Alveolar sacs
 Alveoli
 Pulmonary Capillaries
 Cilia
Photograph of Lungs Without
Connective Tissue
Alveoli
 Location
 Function
 Structure
Alveoli (continued)
Structural Component
Functional Benefit
Alveoli are arranged in grapelike clusters
Greatly increases surface area
for gas exchange
Thin walls- one cell thick
Increases rate of diffusion of
oxygen and carbon dioxide
between alveoli and blood
Densely covered with blood
capillaries
Large contact area between
alveoli and blood supply
Inner walls are lined with
pulmonary surfactant
Lowers the surface tension
within the alveoli and prevents
them from collapsing
Walls of alveoli are moist
Aids rate of diffusion of gases
Alveoli contain stretch receptors
Prevents alveoli from over-filling
with air and causing damage to
the thin walls
Delivery Analogy
Sources Used
"Alveoli." Structure and Function. Cool School, Web. 7 Nov
2009.
<http://www.coolschool.ca/lor/BI12/unit11/U11L03.htm>.
No Author, . "Human Physiology." Respiration. Bio 301, Web. 6
Nov 2009.
<http://people.eku.edu/ritchisong/RITCHISO//301notes6.ht
m>.
Starr, Cecie , and Ralph Taggart. Biology the Unity and
Diversity of Life. Ninth. 1. United States: Brooks/Cole, 2001.
Print.
"Exchanging Oxygen and Carbon Dioxide ." Merck Manuals:
Online Medical Library . Home Edition. NJ, USA: Merck and
Co, Inc, 2009. Print.