Lecture 14: Pulmonary Function Tests (Exam III) Flashcards
Where on the PFT graph below does N2 start to show up on our nitrogen meter?
What is the partial pressure of nitrogen in room air?
560mmHg
What test is depicted in the graph below?
Nitrogen washout test
What should a normal nitrogen concentration in the atmosphere be?
75 - 80 %
What percentage nitrogen should a healthy 20 y/o have at 3 minutes into a nitrogen washout test?
2.5% in 3 min
What is a normal reading on a nitrogen washout test?
2.5% in less than 7 min
What is an abnormal reading on a nitrogen washout test?
2.5% in greater than 7 min
Which of the two nitrogen washout tests below displays an abnormal and uneven air distribution?
Right graph
How might VD be estimated from the graph below?
VD = phase I + ½(phase II)
What lung volume comprises the entirety of phase I in the figure below?
VD (Anatomical Dead Space)
What lung volume(s) comprise phase II in the figure below?
Phase II = Transitional Phase = VD + VA air
Where is air coming from in phase III in the figure below?
What is the nitrogen concentration of this air?
- All areas of the lungs
- [N₂] ≈ 20%
What phase in a closing capacity/volume test is the longest for healthy people?
Phase III
What causes the sharp upswing noted in Phase IV in the figure below?
Lung base small airways start to collapse so [N₂] starts to increase.
In what area of the graph below will we notice excessive compliance?
At what lung volume does inspiration start when conducting a closing volume/capacity test?
RV
What is indicated by 1 in the figure below?
Closing Volume
What is indicated by 2 in the figure below?
Residual Volume
What is indicated by 3 in the figure below?
Closing Capacity
What is indicated by 4 in the figure below?
Vital Capacity