FUNDAMENTALS
OF PHYSIOLOGY
AND ANATOMY
4BBY1060
Lung Physiology &
Anatomy
, LECTURE 12:
Main function of Respiratory System: Provide oxygen (O2) and remove
carbon dioxide (CO2)
1. Ventilation: Exchange of air between atmosphere and alveoli (bulk flow)
2. Exchange of O2 and CO2 between alveolar air and blood in lung capillaries
(diffusion)
3. Transport of O2 and CO2 through pulmonary and systemic circulation
(bulk flow)
4. Exchange of O2 and CO2 between blood in tissue capillaries and cells in
tissues (diffusion)
5. Cellular utilization of O2 and production of CO2
Main topographical features of the upper respiratory tract: Mouth &
nasal cavity, pharynx, and Larynx
The nasal cavity and pharynx:
Lined with epithelium which pseudostratified ciliated columnar with goblet
cells
Air entering swirls around due to irregular shape causing dust particles to
be pushed to the walls, sticking to mucous and moved by cilia to
oropharynx to be swallowed
Mucous moistens the air, mucous membrane is very vascular thus
warming the air
Pathway: Air passed to the pharynx -> nasopharynx ->
oropharynx -> larynx
The larynx:
Acts as an air passageway linking the pharynx with
trachea
Acts as a sphincter to prevent food from entering
trachea
Organ of phonon (vocal cords)
Cellular and histological features of the lower
respiratory tract
Trachea:
Lined with ciliated epithelium (E), submucosal glands,
and C shaped bands of cartilage
o In between C rings there is Epithelium, Lamina propria (LP),
Submucosa (SM) and fibroelastic tissue (F)
Layer Primary bronchi -> Tertiary bronchi
Epithelium Fewer goblet cells than Tall columnar instead of pseudo-
trachea stratified
Lamina Propria More elastin than trachea Thin but elastic
Smooth muscle Thin layer below lamina Well-developed layer, helically
propria arranged
Sub-mucosa & Fewer glands than Decreasing numbers
glands trachea
Cartilage Flattened interconnected Fewer irregular plates
OF PHYSIOLOGY
AND ANATOMY
4BBY1060
Lung Physiology &
Anatomy
, LECTURE 12:
Main function of Respiratory System: Provide oxygen (O2) and remove
carbon dioxide (CO2)
1. Ventilation: Exchange of air between atmosphere and alveoli (bulk flow)
2. Exchange of O2 and CO2 between alveolar air and blood in lung capillaries
(diffusion)
3. Transport of O2 and CO2 through pulmonary and systemic circulation
(bulk flow)
4. Exchange of O2 and CO2 between blood in tissue capillaries and cells in
tissues (diffusion)
5. Cellular utilization of O2 and production of CO2
Main topographical features of the upper respiratory tract: Mouth &
nasal cavity, pharynx, and Larynx
The nasal cavity and pharynx:
Lined with epithelium which pseudostratified ciliated columnar with goblet
cells
Air entering swirls around due to irregular shape causing dust particles to
be pushed to the walls, sticking to mucous and moved by cilia to
oropharynx to be swallowed
Mucous moistens the air, mucous membrane is very vascular thus
warming the air
Pathway: Air passed to the pharynx -> nasopharynx ->
oropharynx -> larynx
The larynx:
Acts as an air passageway linking the pharynx with
trachea
Acts as a sphincter to prevent food from entering
trachea
Organ of phonon (vocal cords)
Cellular and histological features of the lower
respiratory tract
Trachea:
Lined with ciliated epithelium (E), submucosal glands,
and C shaped bands of cartilage
o In between C rings there is Epithelium, Lamina propria (LP),
Submucosa (SM) and fibroelastic tissue (F)
Layer Primary bronchi -> Tertiary bronchi
Epithelium Fewer goblet cells than Tall columnar instead of pseudo-
trachea stratified
Lamina Propria More elastin than trachea Thin but elastic
Smooth muscle Thin layer below lamina Well-developed layer, helically
propria arranged
Sub-mucosa & Fewer glands than Decreasing numbers
glands trachea
Cartilage Flattened interconnected Fewer irregular plates
