NUR968 Pulmonary Physiology Part 1
Test With Complete Solution
Why is the mediastinum slightly displaced to the left? - ANSWER Because of
the heart
True or false: The left lung represents 45% of total lung volume & the right
lung represents 55% of total lung volume - ANSWER True
Anatomically, the mediastinum contains all chest structures EXCEPT what? -
ANSWER Except the lungs
Where are the lungs located? - ANSWER In the pleural cavity
Are the lungs attached to the chest wall? - ANSWER No, the lungs are not
attached to the chest wall & in fact, float within the chest cavity
What is the only area where the lungs are in a "fixed" position? - ANSWER
The hilum
Mediastinum - Anesthetic Significance:
In blunt force trauma, the mediastinal & pleural structures continue to travel
until they are forced to stop. Because the hilum is a fixed structure, this is
often a point where __ occur (aorta, pulmonary vessels, vena cava, bronchi) -
ANSWER Tears
What keeps the lungs inflated? - ANSWER The pleura
"The glue"
What does the pleura do? - ANSWER Protect & cushion the lungs
,Two thin linings or membranes that do this
What is the pleural lining that covers the lungs? - ANSWER Visceral pleura
What is the pleural lining that covers the chest wall? - ANSWER Parietal
pleura
Between the two pleural linings there is a small amount (a few mL) of fluid.
What does this do? - ANSWER It lubricates the surface of the linings
-So the two surfaces glide smoothly over one another (decreases friction &
inflammation)
-The lungs are thus held in place in the thoracic cavity & yet can move freely
What does intrapleural pressure refer to? What is another name for it? -
ANSWER Refers to the pressure inside the pleural cavity
-Also known as the intrathoracic pressure
Is normal breathing negative or positive pressure? - ANSWER Negative
pressure
In normal, quiet breathing, this pressure is slightly below atmospheric
pressure
What are the 3 things that contribute to the negative intrathoracic pressure?
- ANSWER 1. The elasticity of the lungs
2. The elasticity of the thoracic cavity
3. The surface tension created by alveolar fluid
When there is a breach in the pleural space & AIR accumulates, what is this
called? What about when BLOOD accumulates? - ANSWER Air =
,Pneumothorax
Blood = Hemothorax
What zones are the lungs divided into? (2) - ANSWER 1. Conducting zone
2. Respiratory zone
Is the conducting zone involved in air exchange with the blood? - ANSWER
No
Carries air but is not involved in air exchange with blood
What structures does the conducting zone include? These contain what? (3) -
ANSWER Includes the trachea, bronchi & bronchioles
Contain:
1. Cilia
2. Cartilage (not the bronchioles)
3. Smooth muscle
Is the respiratory zone involved in air exchange with the blood? - ANSWER
Yes
Exchange O2 & CO2 here
What structures does the respiratory zone include? These contain what? (3) -
ANSWER Includes the respiratory bronchioles, alveolar ducts, & alveolar sacs
Contain:
1. Alveolar ducts & alveolar sacs have no cilia (respiratory bronchioles do)
2. No cartilage
, 3. Bronchioles & alveolar ducts have some smooth muscle (alveolar sacs do
not)
What does cartilage do? - ANSWER Helps prevent tracheal/bronchial collapse
So why is the respiratory zone more prone to smooth muscle constriction &
collapse? - ANSWER Since it lacks cartilage
General Anatomy - Lung Tissue
Type: Conductive
Function: Bulk gas movement
Structure: __ to __ - ANSWER Type: Conductive
Function: Bulk gas movement
Structure: Trachea to terminal bronchioles
General Anatomy - Lung Tissue
Type: Transitional
Function: Bulk gas movement
Structure: __ - ANSWER Type: Transitional
Function: Bulk gas movement
Structure: Respiratory bronchioles
General Anatomy - Lung Tissue
Type: Transitional
Function: Limited gas exchange
Test With Complete Solution
Why is the mediastinum slightly displaced to the left? - ANSWER Because of
the heart
True or false: The left lung represents 45% of total lung volume & the right
lung represents 55% of total lung volume - ANSWER True
Anatomically, the mediastinum contains all chest structures EXCEPT what? -
ANSWER Except the lungs
Where are the lungs located? - ANSWER In the pleural cavity
Are the lungs attached to the chest wall? - ANSWER No, the lungs are not
attached to the chest wall & in fact, float within the chest cavity
What is the only area where the lungs are in a "fixed" position? - ANSWER
The hilum
Mediastinum - Anesthetic Significance:
In blunt force trauma, the mediastinal & pleural structures continue to travel
until they are forced to stop. Because the hilum is a fixed structure, this is
often a point where __ occur (aorta, pulmonary vessels, vena cava, bronchi) -
ANSWER Tears
What keeps the lungs inflated? - ANSWER The pleura
"The glue"
What does the pleura do? - ANSWER Protect & cushion the lungs
,Two thin linings or membranes that do this
What is the pleural lining that covers the lungs? - ANSWER Visceral pleura
What is the pleural lining that covers the chest wall? - ANSWER Parietal
pleura
Between the two pleural linings there is a small amount (a few mL) of fluid.
What does this do? - ANSWER It lubricates the surface of the linings
-So the two surfaces glide smoothly over one another (decreases friction &
inflammation)
-The lungs are thus held in place in the thoracic cavity & yet can move freely
What does intrapleural pressure refer to? What is another name for it? -
ANSWER Refers to the pressure inside the pleural cavity
-Also known as the intrathoracic pressure
Is normal breathing negative or positive pressure? - ANSWER Negative
pressure
In normal, quiet breathing, this pressure is slightly below atmospheric
pressure
What are the 3 things that contribute to the negative intrathoracic pressure?
- ANSWER 1. The elasticity of the lungs
2. The elasticity of the thoracic cavity
3. The surface tension created by alveolar fluid
When there is a breach in the pleural space & AIR accumulates, what is this
called? What about when BLOOD accumulates? - ANSWER Air =
,Pneumothorax
Blood = Hemothorax
What zones are the lungs divided into? (2) - ANSWER 1. Conducting zone
2. Respiratory zone
Is the conducting zone involved in air exchange with the blood? - ANSWER
No
Carries air but is not involved in air exchange with blood
What structures does the conducting zone include? These contain what? (3) -
ANSWER Includes the trachea, bronchi & bronchioles
Contain:
1. Cilia
2. Cartilage (not the bronchioles)
3. Smooth muscle
Is the respiratory zone involved in air exchange with the blood? - ANSWER
Yes
Exchange O2 & CO2 here
What structures does the respiratory zone include? These contain what? (3) -
ANSWER Includes the respiratory bronchioles, alveolar ducts, & alveolar sacs
Contain:
1. Alveolar ducts & alveolar sacs have no cilia (respiratory bronchioles do)
2. No cartilage
, 3. Bronchioles & alveolar ducts have some smooth muscle (alveolar sacs do
not)
What does cartilage do? - ANSWER Helps prevent tracheal/bronchial collapse
So why is the respiratory zone more prone to smooth muscle constriction &
collapse? - ANSWER Since it lacks cartilage
General Anatomy - Lung Tissue
Type: Conductive
Function: Bulk gas movement
Structure: __ to __ - ANSWER Type: Conductive
Function: Bulk gas movement
Structure: Trachea to terminal bronchioles
General Anatomy - Lung Tissue
Type: Transitional
Function: Bulk gas movement
Structure: __ - ANSWER Type: Transitional
Function: Bulk gas movement
Structure: Respiratory bronchioles
General Anatomy - Lung Tissue
Type: Transitional
Function: Limited gas exchange
