Lecture 1.5 Respiratory Conceptual flashies Flashcards
Describe what is happening in the following graph
The compliance of the lung (P/V) is being shown
As pressure increases, the volume increases as well
What are the values of the numbers that are above the dotted line in the 3rd graph?
positive values
What do points A, C, and D represent
The points where there is no airflow
What does the dotten line on the second graph indicate?
The mount of pressure that is needed to overcome the elastic recoil of the lungs
Using the following diagram, describe what is happening at the end of exhalation
Respiratory muscles relaxed
Diaphragm is high in the thoracic cavity
No airflow
Lung elastic recoil pulls the lung inward
Chest wall elastic recoil pulls the chest outward
Tension created by the two opposing forces (lung elastic and chest wall elastic) –>Negative pleural pressure
Using the following diagram, describe what is happening during inspiration
Diaphragm and other muscles of inspiration contract
Decrease in pleural pressure
Negative pleural pressure transmitted to alveoli; drop in pressure
Gas flows across gradient
Lung volume increases; lung elastic recoil increases (solid arrows) and chest wall recoil decreases (open arrows)
Describe the differences that are seen in the pressure and volume in inhalation and exhalation.. what accounts for this?
Due to a surface tension variation with changes in lung volume. In exhalation, the lungs want to get back to normal
What does OABCD respresent in teh following graph?
The work that is necessary to overcome elastic resistance
What does AECF in the following graph represent?
work necessary to overcome nonelastic resistance
What does AECB represent in the following graph?
work necessary to overcome nonelastic resistance during inspiration
What does ABCF represent in the following graph?
work necessary to overcome nonelastic resistance during exhalation (represents stored elastic energy from inspiration)
What does the following graph show? And why
Lungs with reduced compliance
Elastic work of breathing is increased
Pressure-volume curve is shifted to the right; work of breathing is increased
Increase in the trapezoidal area (oAECD)
Describe the following graph… what is significant about the black arrow?
Graph pf the total work, elastic work, and nonelastic work.
The black arrow is the point that most individuals will fall in regards to respiratory rate BECAUSE it is the point in which the sum of those three numbers is the least, so it is the least energy taxing
How do you calcaulate the transpulmonary pressure?
Ptp= Palv-Ppl
5 cm H2O at rest
What component of the respiratory cycle does this graph represent?
volume change
What component of the respiratory cycle does this graph represent?
Alveolar pressure
What component of the respiratory cycle does this graph represent?
Intrapleural pressure
What component of the respiratory cycle does this graph represent?
air flow
What are the following values…
volume
PA
Ppl
Air flow
at REST, between inspiration and expiration
Volume is 0 L
P 0 cm H O A2
PPL is -5 cm H2O
Air is flow is 0 L/s
What is happening to the following components….
volume
PA
Ppl
Air flow
at MID INSPIRATION
Volume is increasing
P is decreasing A
PPL is decreasing
Air is flowing into the lungs
What is happening to the following components….
volume
PA
Ppl
Air flow
at END INSPIRATION
Volume has reached peak increase
Tidal volume, VT = 500 ml
P has returned to zero A
PPL has decreased to -8 cm H2O Air flow has ceased
What is happening to the following components….
Volume
PA
Ppl
Air
IN MID EXHALATION
Volume is decreasing
P rises A
PPL begins to rise
Air exits the lungs
What is happening to the following components….
Volume
PA
Ppl
Air
IN END EXHALATION
Volume has returned to resting
P decreases to zero A
PPL returns to resting
Air has exited the lungs
Describe the volume/pressure relationship at a lower lung volume
The lungs have to work HARD to get an increase in volume because it is harder to stretch the lungs
** less of a slope
Describe the volume/pressure relationship inhalation at normal lung volumes
Once there is a little air in the lungs, a little pressure change will produce a large volume change
Easier to stretch the lungs; a high slope
Describe the Volume/Pressure Relationship Inhalation at High Lung Volumes
As lungs expand towards TLC, it again becomes difficult to stretch
Small pressure change produces small change in volume
