Online Lab: Muscle Function

Muscle Functions:

1. Place your fingers along the angle of your jaw just in front of your ear. Grit your teeth and observe what happens to the hardness of the muscles in your check. They move up towards your ear and protrude out.

2. With the thumb and little finger of one hand, span the opposite arm's biceps from the elbow to as close to the shoulder as possible. Bend the arm and observe the change in the length of the muscle. The muscle goes from lose to tight.

3. Wrap a strip of paper around your upper arm and mark the circumference of your arm on the paper. Clench your fist tightly and mark the new circumference on the paper. Observe what happens to the circumference of the muscle. The muscle gets bigger.

Effects of Temperature on muscle action:
Normal: 48
Ice Water: 29

Effect of fatigue on muscle action
# of squeezes in 20 seconds
1 40
2 41
3 42
4 32
5 31
6 31
7 22
8 22
9 19
10 12

What are the three changes you observed in a muscle while it is working? The three changes that I notice by doing the lab is that it once your mucsle gets tired it unable to go as fast as it did.

What effects did the cold temperature have on the action of your hand muscle? When your hand muscle get colder it makes it harder for it to go as fast as it did when it was at your normal temperature.