PULMONARY PHYSIOLOGY
INTRODUCTION
‐ Air movement between the environment & cells
‐ Functions of the respiratory system:
• Exchange of gases between environment & blood (O2 and CO2)
• Homeostasis (body pH → equilibrium)
• Protection against pathogens
• Vocalisation
‐ Respiration: transport of oxygen from outside air to cells and transport of
Carbon Dioxide from cells to the outside
‐ Without food = 3 weeks
‐ Without water = 3-4 days
‐ Without oxygen = 3-6 minutes
‐ Respiratory main function
• O2 ↔ CO2
STRUCTURAL CLASSIFICATION
ALYSSA THERON
,FUNCTIONAL CLASSIFICATION
STRUCTURE AND FUNCTION
‐ Nose and nasal cavity
‐ Pharynx
‐ Larynx
‐ Trachea
‐ Bronchi tree
‐ Upper and lower respiratory airways
NOSE AND NASAL CAVITY
‐ External nose – nose
‐ Internal nose – nasal cavity
‐ Lined with mucous membrane: contains ciliates epithelium and mucous
secreting goblet cells
‐ Rich blood supply
• Dilation of nasal blood vessels (cold/ flu, allergy, toxins) – oedema of
mucous membranes obstruct airways
ALYSSA THERON
, ‐ Nasal cavity: functions of mucous membrane
• Warms air
• Moistens/ humidifies incoming air (so doesn’t dry out)
• Filters incoming air – nose hairs guard nostrils.
Cilia and sticky mucous entrap dust & microorganisms
Cilia moves mucous that has entrapped these microorganisms
towards pharynx where they can be swallowed/ coughed out
PHARYNX (THROAT)
‐ Functions as common passage for:
• Transport of food from oral cavity – oesophagus
• Transport of air from nasal cavity – larynx
‐ During swallowing soft palate is raised reflexly – prevents food from
entering nasal cavity
‐ Larynx is elevated and breathing is inhibited reflexly – prevents food
entering trachea and causing choking
** hypo-pharynx is also known as laryngeal pharynx
LARYNX (VOICE BOX)
‐ Continuous – trachea (superior)
‐ The functions of the larynx:
• To act as a switching mechanism to route air and food into the proper
channels
• Voice production
‐ Inner surface of larynx – mucous membrane (has goblet cells that produce
mucous)
ALYSSA THERON
, TRACHEA (WINDPIPE)
‐ Larynx → trachea → primary bronchi
‐ C-shaped cartilaginous rings: gives firmness to the wall, prevents airways
from collapsing
‐ Mucous membrane: lined with ciliated epithelium
‐ Also responsible for filtering incoming air
BRONCHIAL TREE
‐ Trachea → right & left primary bronchi
‐ Bronchi – lined with ciliated columnar epithelium
‐ Secondary bronchi → tertiary bronchi → bronchioles → terminal
bronchioles → respiratory bronchioles → alveolar ducts
‐ Smooth muscle & elastic fibers – allow expansion and recoiling to increase/
decrease airflow in structures
‐ branching becomes more numerous then walls think out – alveoli design
allows for increased surface area
‐ More branches = smaller structures & smaller walls, therefore increased
surface area
ALYSSA THERON
INTRODUCTION
‐ Air movement between the environment & cells
‐ Functions of the respiratory system:
• Exchange of gases between environment & blood (O2 and CO2)
• Homeostasis (body pH → equilibrium)
• Protection against pathogens
• Vocalisation
‐ Respiration: transport of oxygen from outside air to cells and transport of
Carbon Dioxide from cells to the outside
‐ Without food = 3 weeks
‐ Without water = 3-4 days
‐ Without oxygen = 3-6 minutes
‐ Respiratory main function
• O2 ↔ CO2
STRUCTURAL CLASSIFICATION
ALYSSA THERON
,FUNCTIONAL CLASSIFICATION
STRUCTURE AND FUNCTION
‐ Nose and nasal cavity
‐ Pharynx
‐ Larynx
‐ Trachea
‐ Bronchi tree
‐ Upper and lower respiratory airways
NOSE AND NASAL CAVITY
‐ External nose – nose
‐ Internal nose – nasal cavity
‐ Lined with mucous membrane: contains ciliates epithelium and mucous
secreting goblet cells
‐ Rich blood supply
• Dilation of nasal blood vessels (cold/ flu, allergy, toxins) – oedema of
mucous membranes obstruct airways
ALYSSA THERON
, ‐ Nasal cavity: functions of mucous membrane
• Warms air
• Moistens/ humidifies incoming air (so doesn’t dry out)
• Filters incoming air – nose hairs guard nostrils.
Cilia and sticky mucous entrap dust & microorganisms
Cilia moves mucous that has entrapped these microorganisms
towards pharynx where they can be swallowed/ coughed out
PHARYNX (THROAT)
‐ Functions as common passage for:
• Transport of food from oral cavity – oesophagus
• Transport of air from nasal cavity – larynx
‐ During swallowing soft palate is raised reflexly – prevents food from
entering nasal cavity
‐ Larynx is elevated and breathing is inhibited reflexly – prevents food
entering trachea and causing choking
** hypo-pharynx is also known as laryngeal pharynx
LARYNX (VOICE BOX)
‐ Continuous – trachea (superior)
‐ The functions of the larynx:
• To act as a switching mechanism to route air and food into the proper
channels
• Voice production
‐ Inner surface of larynx – mucous membrane (has goblet cells that produce
mucous)
ALYSSA THERON
, TRACHEA (WINDPIPE)
‐ Larynx → trachea → primary bronchi
‐ C-shaped cartilaginous rings: gives firmness to the wall, prevents airways
from collapsing
‐ Mucous membrane: lined with ciliated epithelium
‐ Also responsible for filtering incoming air
BRONCHIAL TREE
‐ Trachea → right & left primary bronchi
‐ Bronchi – lined with ciliated columnar epithelium
‐ Secondary bronchi → tertiary bronchi → bronchioles → terminal
bronchioles → respiratory bronchioles → alveolar ducts
‐ Smooth muscle & elastic fibers – allow expansion and recoiling to increase/
decrease airflow in structures
‐ branching becomes more numerous then walls think out – alveoli design
allows for increased surface area
‐ More branches = smaller structures & smaller walls, therefore increased
surface area
ALYSSA THERON
