FISDAP Airway Exam
Respiratory System: Ventilation and
Respiration
I. Anatomy of the Airway
A. Upper Airway Structures
Nose: Initial entry point for air.
Mouth: Alternative entry point for air.
Tongue: Can obstruct the airway if not properly positioned.
Jaw: Supports the tongue and influences airway patency.
Pharynx: Passageway for both air and food, divided into:
o Nasopharynx: Connects the nasal cavity to the oropharynx.
o Oropharynx: Connects the oral cavity to the laryngopharynx.
o Laryngopharynx: Connects the oropharynx to the larynx and
esophagus.
Larynx (Voice Box): Contains the vocal cords and is a key landmark
dividing the upper and lower airways.
B. Lower Airway Structures
Larynx:
o Thyroid Cartilage (Adam's Apple): Anterior prominence.
o Cricothyroid Membrane: Important landmark for emergency airway
access.
o Cricoid Cartilage: Ring-shaped cartilage inferior to the thyroid
cartilage.
Trachea (Windpipe): Cartilaginous tube extending from the larynx to the
bronchi.
Bronchi: The trachea branches into the right and left main bronchi, which
enter the lungs.
o The right bronchus is generally shorter, wider, and more vertical
than the left.
Bronchioles: Smaller airways branching from the bronchi within the lungs.
Alveoli: Tiny air sacs where gas exchange occurs.
,C. Structures Involved in Ventilation
Air passes through the following structures during ventilation:
1. Atmosphere
2. Nose
3. Nasopharyngeal Space / Oropharyngeal Space (if mouth breathing)
4. Pharynx
5. Larynx
6. Trachea
7. Bronchi
8. Bronchioles
9. Alveoli
D. Anatomy of the Lungs
Lobes:
o Right Lung: Has three lobes.
o Left Lung: Has two lobes.
Pleura: Membranes surrounding the lungs:
o Visceral Pleura: Lines the surface of the lungs.
o Parietal Pleura: Lines the inner surface of the thoracic cavity.
o Pleural Space: The potential space between the visceral and parietal
pleura, containing a small amount of lubricating fluid.
E. Other Important Structures
Glottis: The opening between the vocal cords, the narrowest part of the
adult airway. Contains defense reflexes to protect the lower airway.
Carina: The point where the trachea bifurcates into the left and right main
bronchi.
Mediastinum: The space between the lungs, containing the heart, great
vessels, esophagus, trachea, major bronchi, and nerves.
II. Physiology of Respiration and Ventilation
A. Ventilation vs. Respiration
Ventilation: The mechanical process of moving air into and out of the
lungs (air movement).
, Respiration: The physiological process of gas exchange at two levels:
o External Respiration: Exchange of O2 and CO2 between the alveoli
and the blood in the pulmonary capillaries.
o Internal Respiration: Exchange of O2 and CO2 between the
systemic capillaries and the cells of the body.
Purpose of Respiration:
Provides O2 to cells for metabolic processes.
Removes waste products, primarily CO2.
Helps regulate the pH of the blood.
B. Function of Nasal Passages and Nasopharynx
The primary purpose is to warm and humidify the air as it passes through,
preparing it for the lower airways.
C. Muscles Involved in Breathing
Inhalation (Active Process):
o Diaphragm: The primary muscle of respiration; contraction increases
the volume of the thoracic cavity.
o Intercostal Muscles: Muscles between the ribs that assist in
expanding the chest cavity.
o Cervical Muscles (Neck): Accessory muscles used during labored
breathing.
o Abdominal Muscles: Can assist in forced inhalation.
o Pectoral Muscles: Can assist in forced inhalation.
Exhalation (Passive Process in Normal Breathing): Results from the
relaxation of the diaphragm and intercostal muscles, causing the thoracic
cavity to decrease in volume. Active exhalation involves the abdominal
muscles.
D. Pressure Dynamics in Ventilation
Air moves into the lungs because of negative pressure created within the thoracic
cavity when the diaphragm contracts and the chest expands. This pressure
difference between the atmosphere and the alveoli drives airflow.
E. Control of Breathing
Respiratory System: Ventilation and
Respiration
I. Anatomy of the Airway
A. Upper Airway Structures
Nose: Initial entry point for air.
Mouth: Alternative entry point for air.
Tongue: Can obstruct the airway if not properly positioned.
Jaw: Supports the tongue and influences airway patency.
Pharynx: Passageway for both air and food, divided into:
o Nasopharynx: Connects the nasal cavity to the oropharynx.
o Oropharynx: Connects the oral cavity to the laryngopharynx.
o Laryngopharynx: Connects the oropharynx to the larynx and
esophagus.
Larynx (Voice Box): Contains the vocal cords and is a key landmark
dividing the upper and lower airways.
B. Lower Airway Structures
Larynx:
o Thyroid Cartilage (Adam's Apple): Anterior prominence.
o Cricothyroid Membrane: Important landmark for emergency airway
access.
o Cricoid Cartilage: Ring-shaped cartilage inferior to the thyroid
cartilage.
Trachea (Windpipe): Cartilaginous tube extending from the larynx to the
bronchi.
Bronchi: The trachea branches into the right and left main bronchi, which
enter the lungs.
o The right bronchus is generally shorter, wider, and more vertical
than the left.
Bronchioles: Smaller airways branching from the bronchi within the lungs.
Alveoli: Tiny air sacs where gas exchange occurs.
,C. Structures Involved in Ventilation
Air passes through the following structures during ventilation:
1. Atmosphere
2. Nose
3. Nasopharyngeal Space / Oropharyngeal Space (if mouth breathing)
4. Pharynx
5. Larynx
6. Trachea
7. Bronchi
8. Bronchioles
9. Alveoli
D. Anatomy of the Lungs
Lobes:
o Right Lung: Has three lobes.
o Left Lung: Has two lobes.
Pleura: Membranes surrounding the lungs:
o Visceral Pleura: Lines the surface of the lungs.
o Parietal Pleura: Lines the inner surface of the thoracic cavity.
o Pleural Space: The potential space between the visceral and parietal
pleura, containing a small amount of lubricating fluid.
E. Other Important Structures
Glottis: The opening between the vocal cords, the narrowest part of the
adult airway. Contains defense reflexes to protect the lower airway.
Carina: The point where the trachea bifurcates into the left and right main
bronchi.
Mediastinum: The space between the lungs, containing the heart, great
vessels, esophagus, trachea, major bronchi, and nerves.
II. Physiology of Respiration and Ventilation
A. Ventilation vs. Respiration
Ventilation: The mechanical process of moving air into and out of the
lungs (air movement).
, Respiration: The physiological process of gas exchange at two levels:
o External Respiration: Exchange of O2 and CO2 between the alveoli
and the blood in the pulmonary capillaries.
o Internal Respiration: Exchange of O2 and CO2 between the
systemic capillaries and the cells of the body.
Purpose of Respiration:
Provides O2 to cells for metabolic processes.
Removes waste products, primarily CO2.
Helps regulate the pH of the blood.
B. Function of Nasal Passages and Nasopharynx
The primary purpose is to warm and humidify the air as it passes through,
preparing it for the lower airways.
C. Muscles Involved in Breathing
Inhalation (Active Process):
o Diaphragm: The primary muscle of respiration; contraction increases
the volume of the thoracic cavity.
o Intercostal Muscles: Muscles between the ribs that assist in
expanding the chest cavity.
o Cervical Muscles (Neck): Accessory muscles used during labored
breathing.
o Abdominal Muscles: Can assist in forced inhalation.
o Pectoral Muscles: Can assist in forced inhalation.
Exhalation (Passive Process in Normal Breathing): Results from the
relaxation of the diaphragm and intercostal muscles, causing the thoracic
cavity to decrease in volume. Active exhalation involves the abdominal
muscles.
D. Pressure Dynamics in Ventilation
Air moves into the lungs because of negative pressure created within the thoracic
cavity when the diaphragm contracts and the chest expands. This pressure
difference between the atmosphere and the alveoli drives airflow.
E. Control of Breathing
