PCOL 838 PULMONARY E2 EXAM 2025
QUESTIONS AND ANSWERS
What are parts of the respiratory zone?
The conducting zone
- nose, pharynx, larynx, trachea, bronchi, and bronchioles
The respiratory zone
- respiratory bronchioles, alveolar ducts, and alveoli
What part in lungs does allow gas exchange between the lungs and the blood?
alveoli
main airways (bronchi) branch off into smaller and smaller passageways the smallest, called
bronchioles, lead to tiny air sacs (alveoli).
What are the two principal physiologic roles of the lungs?
1. To make oxygen available to tissues for metabolism
2. To remove the main byproduct of that metabolism
3. Fluid homeostasis
4. Host defense.
What mechanism do the pulmonary arteries have for matching alveolar perfusion with
ventilation?
Hypoxic pulmonary vasoconstriction (HPV) is a homeostatic mechanism for matching of
regional perfusion and ventilation in the lung.
1. ↓ alveolar PO2 = reflex vasoconstriction of pulmonary arterioles, diverting blood to better
oxygenated lung segments.
2. ↑ alveolar PO2 = vasodilation of pulmonary arterioles.
1 @COPYRIGHT THESTAR 2025/2026
, What are the roles of the connective tissue and surfactant systems in lung function?
The connective tissue fibers are highly organized collagen and elastic structures.
Surfactant is a complex material produced by type II alveolar cells (multiple phospholipids and
specific associated proteins), enhancing anatomic stability of alveoli and reducing surface
tension to prevent the collapse of alveoli with a reduction of alveolar volume during
expiration.
Visceral Pleura covers the outer
surface of lungs and connective tissue fibers and surfactant serve to maintain the anatomic
integrity of visceral pleura.
Surfactant
a complex material produced by type II alveolar cells (multiple phospholipids and specific
associated proteins), enhancing anatomic stability of alveoli and reducing surface
tension to prevent the collapse of alveoli with a reduction of alveolar volume during
expiration.
What is a Diaphragm?
the principal bellows muscle for ventilation under normal conditions
" Upon inhalation, diaphragm contracts and flattens and chest cavity enlarges, creating a
vacuum, which pulls air into the lungs.
" Upon exhalation, diaphragm relaxes and returns to its domelike shape, and air is forced out of
the lungs.
Airway resistance
Opposition to flow caused by the forces of friction (the ratio of driving pressure to the rate of
air flow)
Resistance to flow in airways depends on type of air flow (laminar or turbulent), the
dimensions (diameter) of airway, and surface tension of fluid lining alveoli (surfactant).
What are the major sites of resistance to airflow in the lungs?
Trachea and bronchus actually provide greater resistance to flow than do the more numerous
small airways (e.g., terminal bronchiole).
What are the different roles of the pulmonary and bronchial arteries?
" Pulmonary arteries supply 99% of deoxygenated blood from heart at low pressure → to lungs
and participate in gas exchange at alveolar capillary membrane.
2 @COPYRIGHT THESTAR 2025/2026
QUESTIONS AND ANSWERS
What are parts of the respiratory zone?
The conducting zone
- nose, pharynx, larynx, trachea, bronchi, and bronchioles
The respiratory zone
- respiratory bronchioles, alveolar ducts, and alveoli
What part in lungs does allow gas exchange between the lungs and the blood?
alveoli
main airways (bronchi) branch off into smaller and smaller passageways the smallest, called
bronchioles, lead to tiny air sacs (alveoli).
What are the two principal physiologic roles of the lungs?
1. To make oxygen available to tissues for metabolism
2. To remove the main byproduct of that metabolism
3. Fluid homeostasis
4. Host defense.
What mechanism do the pulmonary arteries have for matching alveolar perfusion with
ventilation?
Hypoxic pulmonary vasoconstriction (HPV) is a homeostatic mechanism for matching of
regional perfusion and ventilation in the lung.
1. ↓ alveolar PO2 = reflex vasoconstriction of pulmonary arterioles, diverting blood to better
oxygenated lung segments.
2. ↑ alveolar PO2 = vasodilation of pulmonary arterioles.
1 @COPYRIGHT THESTAR 2025/2026
, What are the roles of the connective tissue and surfactant systems in lung function?
The connective tissue fibers are highly organized collagen and elastic structures.
Surfactant is a complex material produced by type II alveolar cells (multiple phospholipids and
specific associated proteins), enhancing anatomic stability of alveoli and reducing surface
tension to prevent the collapse of alveoli with a reduction of alveolar volume during
expiration.
Visceral Pleura covers the outer
surface of lungs and connective tissue fibers and surfactant serve to maintain the anatomic
integrity of visceral pleura.
Surfactant
a complex material produced by type II alveolar cells (multiple phospholipids and specific
associated proteins), enhancing anatomic stability of alveoli and reducing surface
tension to prevent the collapse of alveoli with a reduction of alveolar volume during
expiration.
What is a Diaphragm?
the principal bellows muscle for ventilation under normal conditions
" Upon inhalation, diaphragm contracts and flattens and chest cavity enlarges, creating a
vacuum, which pulls air into the lungs.
" Upon exhalation, diaphragm relaxes and returns to its domelike shape, and air is forced out of
the lungs.
Airway resistance
Opposition to flow caused by the forces of friction (the ratio of driving pressure to the rate of
air flow)
Resistance to flow in airways depends on type of air flow (laminar or turbulent), the
dimensions (diameter) of airway, and surface tension of fluid lining alveoli (surfactant).
What are the major sites of resistance to airflow in the lungs?
Trachea and bronchus actually provide greater resistance to flow than do the more numerous
small airways (e.g., terminal bronchiole).
What are the different roles of the pulmonary and bronchial arteries?
" Pulmonary arteries supply 99% of deoxygenated blood from heart at low pressure → to lungs
and participate in gas exchange at alveolar capillary membrane.
2 @COPYRIGHT THESTAR 2025/2026
