Cardiac Output & Pulmonary Ventilation

by Greg Crowther

Cardiac output is the rate at which blood is pumped by the heart; pulmonary ventilation (or minute ventilation) is the rate at which air is taken in by the respiratory system. This jingle, originally written for Biology 352 at UW-Bothell, compares the equations for calculating these two rates. Parallels in the two equations are emphasized by the parallels in the verses, with only a few words changed between the cardiac output verses and the pulmonary ventilation verses; compare verse 1 with verse 2, and verse 3 with verse 4. You can choose among these verses according to your learning goals; for example, if you are focusing solely on respiration, you can focus on verses 3 and 4.

[Intro]
For quantitation
Of circulation
And respiration,
We have equations!

[Verse 1]
Volume moved per beat
Times number of beats per minute
Equals volume of blood per minute;
That’s all this equation has in it!

[Verse 2]
Volume moved per breath
Times number of breaths per minute
Equals volume of air per minute;
That’s all this equation has in it!

[Verse 3]
Volume moved per beat
Equals end-diastolic volume
Minus end-systolic volume;
Now find some examples and solve 'em!

[Verse 4]
Volume moved per breath
Equals end-inspiratory volume
Minus end-expiratory volume;
Now find some examples and solve 'em!

• MP3 (demo)

• music video

• sheet music (with melody play-back)

Songs like this one can be used during class meetings and/or in homework assignments. Either way, the song will be most impactful if students DO something with it, as opposed to just listening.

An initial, simple follow-up activity could be to answer the study questions below. A more extensive interaction with the song might entail (A) learning to sing it, using an audio file and/or sheet music as a guide, and/or (B) illustrating it with pictures, bodily poses, and/or bodily movements. The latter activity could begin with students identifying the most important or most challenging content of the song, and deciding how to illustrate that particular content.

Depending on the learning goals, some verses of this song may be omitted. For example, a "cardiovascular-only" version would use verses 1 and 3, while a "respiration-only" version would use verses 2 and 4. The current MP3 demo file and video cover verses 1 and 2.

(1) The terms cardiac output, stroke volume, heart rate, pulmonary ventilation, tidal volume, and respiration rate are not included in the jingle’s lyrics, but their definitions ARE included. Which definitions go with which terms?

(2) Which term in the pulmonary ventilation equation is the respiratory equivalent of stroke volume? Which term is the respiratory equivalent of heart rate?

(3) How do these variables change when you start performing aerobic exercise?

(4) At one particular moment in time, Cardi P has a cardiac output of 10 liters per minute and a pulmonary ventilation of 10 liters per minute. Is this just coincidental, or should these numbers generally match each other?

(5) Verse 3 refers to end-diastolic volume and end-systolic volume. What are diastole and systole, respectively?

(6) One component of the pulmonary ventilation equation is respiration rate in breaths per minute. What is a typical respiration rate for a resting adult human?

(7) Considering the specific content covered by this song, is there anything important that is missing, unclear, or misleading? If so, what?

(Answers may be found on the answers page.)