Muscle Inquiry

Part 1: Muscle Fatigue

Anyone who has performed strenuous exercise knows that muscle can soon begin to ache or show fatigue. In this activity you will examine how quickly some of your muscles begin to tire.

Rest your elbow on the desk so that the palm of your hand is facing toward you . Open and close your hand forcefully as many times as you can in 30 seconds. Repeat for more times, each time recording your results in the data table.

Stand up. Hold your textbook in your hand with your arm positioned straight down at your side. Keeping your arm straight, lift the book to shoulder height, then lower it. Count the number of times you can raise and lower your arm in 30 seconds. Repeat four more times and record your results in the data table. Calculate your average number of fists and lifts.

trial / number of fists made / number of arm lifts
1
2
3
4
5

AVERAGE FISTS: ______AVERAGE LIFTS: ______

Obtain “AVERAGE” results for 9 other classmates of the same sex. On the graph below, graph these results using different colored pencils (or use different patterns) to distinguish the “fists” and “lifts”.

person # / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9
average fists
average lifts

Part 2: Muscle Tissue/Cells

In the space below, sketch striated and heart muscle tissue. Make sure you take your time to accurately sketch what you see. Label individual cells in each, and label the striations that you cell in the striated muscle tissue. Make sure you label what slide it is and the total magnification.

Slide: ______Slide: ______

Total magnification: ______Total magnification: ______

Part 3: Muscle Pairs: Triceps/Biceps

At this station meter sticks represents bones and irrigation tubing represents muscles. The muscles are held to the bone by tape. The tape represents tendons. At station 9 shows the triceps. Contract the triceps, making sure the notch at the end of the radius/ulna stays at the corner of the humerus. Draw the triceps muscle contracting and draw and arrow showing the direction of the radius/ulna movement. Be sure to accurately draw where the muscle is attached to both bones. Do the same thing for station #10 and the biceps. (note the diagrams below show the starting position of the bones).