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YOUR LOGO PHYSIOLOGY OF THE RESPIRATORY SYSTEM Universiti Malaysia Kelantan, Faculty of Vet. Medicine Dr. Erkihun Aklilu (Lecturer) 4 th April 2013
YOUR LOGO
PHYSIOLOGY OF THE RESPIRATORY SYSTEM
Universiti Malaysia Kelantan, Faculty of Vet. Medicine
Dr. Erkihun Aklilu (Lecturer)
4th April 2013
YOUR LOGO
The Respiratory System
Function and Structure
Primary function of the respiratory system is exchange of O2 and CO2
Other functions such as:- blood reservoir- heat exchange- metabolism- immunological and mechanical defense
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YOUR LOGO
The Respiratory System
Function and Structure
Anatomic Division
The upper respiratory tract - the airways from the nose through the larynx.
The lower respiratory tract - the airways from the trachea through the lungs.
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YOUR LOGOPage 4
The Respiratory System
Conducting Zone Functions:
Air distribution to the gas exchange surface.
Warming and humidifying the air.
Serves as a part of body defense system.
Prevents the alveolar oxygen and carbon dioxide partial
pressures from extreme changes.
YOUR LOGO
The Respiratory System
Function and Structure
Physiologic Division
The conducting zone – the airways that serve for airflow, mainly from the nostrils through the bronchioles
The transitional and respiratory zones - the respiratory bronchioles, alveolar ducts and alveoli.
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YOUR LOGOPage 6
The Respiratory System
Cell of the Respiratory Tract
Capillary endothelium – forms the alveoli
Alveolar type I cells - also 0.1 µm thick Impermeable to albumin
Allow extravasation of macrophages
Unable to divide
Highly sensitive to hyperoxia
Alveolar type II cells - rounded cells at septal junctions Produce surfactant
Resistant to hyperoxia
Alveolar type III cells / "brush" cells
YOUR LOGOPage 7
The Respiratory System
Cell of the Respiratory Tract
Alveolar macrophages - Present in alveoli & airways- Normal defence & scavenging
Mast Cells
Non-ciliated bronchial epithelial, "Clara", cells
APUD cells
YOUR LOGOPage 8
Lung Volumes
Primary lung volumes
Residual Volume (RV): Is the volume remaining inthe lungs and airways following a maximumexpiratory effort
Expiratory Reserve Volume (ERV): Maximumvolume that can still be expired by forceful expirationafter the end of a normal tidal expiration
YOUR LOGOPage 9
Lung Volumes
Primary lung volumes
Tidal Volume (TV): Volume of gas exchanged each breath
Inspiratory Reserve Volume (IRV) : Maximumvolume that can be inspired over and beyond thenormal tidal volume
YOUR LOGOPage 10
Lung Volumes
Secondary derived capacities
Total Lung Capacity (TLC): Maximum volume of gas that the lungs (and airways) can contain. TLC = VC + RV
Vital Capacity (VC): Maximum volume of gas that can be exchanged in a single breath. VC = TV + IRV + ERV
YOUR LOGOPage 11
Lung Volumes
Secondary derived capacities
Inspiratory Capacity (IC): Maximum volume of gasthat can be inspired from the of expiratory positionIC = TV + IRV
Functional Residual Capacity (FRC): Volume ofgas remaining in the lungs (and airways) at the endof expiratory position. FRC = RV + ERV
