PATHOLO BASIC MEDICAL PATHOLOGY (LECTURE)
TERM 2, A.Y. 2024-2025 THIRD LONG EXAMINATION
LECTURE 5 Respiratory Center
THE RESPIRATORY SYSTEM
1 Overview
Anatomy of the Respiratory System
● Bronchopulmonary Segments – functional unit of the lung
● Medulla Oblongata – respiratory center of the body
Conducting Zone ● Parts of the respiratory system that conducts air and is
not involved in gas exchange
Respiratory Zone ● Parts of the respiratory system that is involved in gas
exchange
Dead Space ● Anatomic Dead Space – involved in conducting zone
● Alveolar Dead Space – involved in respiratory zone
● Physiologic Dead Space – anatomic + alveolar d.s.
Chest Radiograph
A. Airways
B. Breathing – The lungs and pleural spaces
C. Circulation – Cardiomediastinal contour
D. Disability – Ex: Fractures
E. Everything else – Ex: Pneumoperitoneum
BASIC MEDICAL PATHOLOGY (LECTURE) | THIRD LONG EXAMINATION 1
, PATHOLO TERM 2, A.Y. 2024-2025
Muscles involved in Breathing
Main Muscle ● Diaphragm; dome-shaped
● During inspiration: intrathoracic pressure falls (becomes
more negative)
● During expiration: intrathoracic pressure increases
(becomes more positive)
Type I Pneumocyte ● 96-98% of surface area
● For gas exchange
Type II Pneumocyte ● Produces surfactant which decreases surface tension
● Dipalmitoylphosphatidylcholine
○ Main component of surfactant
Accessory Muscles ● Used by the body in moments of ‘air hunger’ Respiration
Physiology of the Respiratory System ● AKA ‘breathing’
● Made up of 5 step process
Functions of the Respiratory System 1. Pulmonary Ventilation
2. Gas exchange of O2 and CO2
1. Oxygenates blood coming from the right ventricle of the heart through the 3. Gas transport of O2 and CO2
pulmonary artery 4. Gas exchange of O2 and CO2 between blood in tissue capillaries and cells
2. Vocalization of sounds 5. Cellular respiration
3. Has metabolic capabilities
● Metabolizes vasoactive amines (95% of Serotonin), cytokines, proteins
4. Location of Angiotensin Converting Enzyme (ACE) which helps in blood pressure
regulation
5. Helps in maintenance of the Acid-Base Balance
6. Mucociliary clearance system – prevents and expels foreign objects before reaching
the lungs
7. Humidifies air – dry air can damage the respiratory lining
8. Immune Defense
● Mucosa-Associated Lymphoid Tissue (MALT) are tissues in the immune system
that illustrate adaptive immune response
● Active secretion of IgA by the respiratory lining
Alveoli
● Site of gas exchange
BASIC MEDICAL PATHOLOGY (LECTURE) | THIRD LONG EXAMINATION 2
TERM 2, A.Y. 2024-2025 THIRD LONG EXAMINATION
LECTURE 5 Respiratory Center
THE RESPIRATORY SYSTEM
1 Overview
Anatomy of the Respiratory System
● Bronchopulmonary Segments – functional unit of the lung
● Medulla Oblongata – respiratory center of the body
Conducting Zone ● Parts of the respiratory system that conducts air and is
not involved in gas exchange
Respiratory Zone ● Parts of the respiratory system that is involved in gas
exchange
Dead Space ● Anatomic Dead Space – involved in conducting zone
● Alveolar Dead Space – involved in respiratory zone
● Physiologic Dead Space – anatomic + alveolar d.s.
Chest Radiograph
A. Airways
B. Breathing – The lungs and pleural spaces
C. Circulation – Cardiomediastinal contour
D. Disability – Ex: Fractures
E. Everything else – Ex: Pneumoperitoneum
BASIC MEDICAL PATHOLOGY (LECTURE) | THIRD LONG EXAMINATION 1
, PATHOLO TERM 2, A.Y. 2024-2025
Muscles involved in Breathing
Main Muscle ● Diaphragm; dome-shaped
● During inspiration: intrathoracic pressure falls (becomes
more negative)
● During expiration: intrathoracic pressure increases
(becomes more positive)
Type I Pneumocyte ● 96-98% of surface area
● For gas exchange
Type II Pneumocyte ● Produces surfactant which decreases surface tension
● Dipalmitoylphosphatidylcholine
○ Main component of surfactant
Accessory Muscles ● Used by the body in moments of ‘air hunger’ Respiration
Physiology of the Respiratory System ● AKA ‘breathing’
● Made up of 5 step process
Functions of the Respiratory System 1. Pulmonary Ventilation
2. Gas exchange of O2 and CO2
1. Oxygenates blood coming from the right ventricle of the heart through the 3. Gas transport of O2 and CO2
pulmonary artery 4. Gas exchange of O2 and CO2 between blood in tissue capillaries and cells
2. Vocalization of sounds 5. Cellular respiration
3. Has metabolic capabilities
● Metabolizes vasoactive amines (95% of Serotonin), cytokines, proteins
4. Location of Angiotensin Converting Enzyme (ACE) which helps in blood pressure
regulation
5. Helps in maintenance of the Acid-Base Balance
6. Mucociliary clearance system – prevents and expels foreign objects before reaching
the lungs
7. Humidifies air – dry air can damage the respiratory lining
8. Immune Defense
● Mucosa-Associated Lymphoid Tissue (MALT) are tissues in the immune system
that illustrate adaptive immune response
● Active secretion of IgA by the respiratory lining
Alveoli
● Site of gas exchange
BASIC MEDICAL PATHOLOGY (LECTURE) | THIRD LONG EXAMINATION 2
