Chapter 32, Problem 30A

Summary Introduction

To compare:

Cardiac muscle, smooth muscle and fast-twitch muscle.

Introduction:

Fast-twitch muscles are a kind of twitch muscles whereas the cardiac and smooth muscles are the types of vertebrate muscle tissue.

Explanation of Solution

Cardiac muscle or myocardium is a type of vertebrate muscle. They constitute the tissue of the heart wall and control its contraction. They keep the pumping of the heart by involuntary movements which is done with the help of pacemaker cells.

Smooth muscle is a type of vertebrate muscle tissue, used for applying pressure to organs. It is formed of sheets of smooth cells. Other proteins support the fibers of actin and myosin running throughout the cell. They are found in the walls of hollow organs as in the stomach, uterus, intestine, etc.

Out of the two twitch muscles, fast-twitch muscles are the ones that help with the sudden bursts of energy required in some activities like sprinting and jumping.

Conclusion

Fast-twitch muscle is a twitch muscle, whereas the cardiac and smooth muscles are vertebrate muscle tissue. So fast-twitch muscle is the one that doesn’t belong with the others.