How Muscles Contract
by Greg Crowther
This song (originally written for Biology 241 at South Seattle College) builds a model of excitation-contraction coupling, i.e., the key steps by which motor neurons stimulate muscles to contract.
 A motor neuron transmits ACh;
ACh opens sodium channels;
 Sodium causes depolarization;
Depolarization triggers the SR....
 And the SR releases calcium ions,
And the calcium ions bind to troponin,
 And troponin gives tropomyosin a tug,
And tropomyosin accommodates myosin,
 And myosin pulls on the actin, child --
The myosin pulls on the actin.
• MP3 (demo, with Two of a Kind)
• 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) designing kinesthetic movements ("dance moves") to embody it. 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.
(1) What does it mean that "tropomyosin accommodates myosin"?
(2) What does SR stand for?
(3) To depolarize a muscle cell, does sodium move into the cell or out of it?
(4) What does ACh stand for?
(Answers may be found on the answers page.)