QUESTION: Your horse is powered by three muscle types:

1. the heart’s cardiac muscle;

2. smooth muscle lining internal organs and driving involuntary actions, such as movement of food through the intestines; and

3. skeletal, or voluntary, muscle attaching primarily to bones to move body parts under direction of the central nervous system.

Which muscle predominates in your horse’s body, and approximately how much of his total weight does it account for?

Pop Quiz Answer

3. Skeletal muscle makes up 45 percent of your horse’s body weight, far more even than the bones. In addition to powering locomotion and movement, these strong, blood-rich, elastic structures protect the skeleton by distributing force and absorbing shock.