muscle twitch

Practical Report
Human Biology/Physiology

Name:

Student ID:

Please include the recorded charts along with this report. Charts may be copied to MS Power Point.

Exercise 1: The effects of nerve stimulation

A. Describe briefly what you have done for this section (maximum 100 words).

B. What are the observations that you have made? (maximum 150 words)

The experiment was carried out by using the amplitudes as low as 0.00mA to locate the twitching. But volunteer was not able to feel any twitch response from the amplitude of 0.00mA to 6.5mA. But to be close to accurate we located the twitch response by using the amplitude of 10.0mA.

Exercise 2: Twitch response and recruitment

A. Describe briefly what you have done for this section (maximum 100 words).

B. What are the observations that you have made? (maximum 150 words)

C. Please provide answers to the following questions.
1. Did you get a measurable twitch with a stimulus of 0 mA?
There was no measurable twitch obtained with a stimulus of 0mA

2. What was the smallest current required to produce a contraction (the threshold current)?
According to Table 1.1, the smallest current required to produce a contraction was 6.5mA

3. What was the smallest current required to produce the maximum (largest) contraction?

4. What happened to the number of fibers contracting as the current was raised from threshold to that required to produce a maximal contraction?
5. Why does varying the stimulus strength affect the twitch force?

D. Please fill-in the following Table and provide the stimulus response’s graf:

Table . The effects of varying stimulus strength on twitch force.
Stimulus
Response
Stimulus
Response
Stimulus
Response
0.0 mA 0.00mV
7.0 mA 26.57mV
14.0 mA

0.5 mA 0.00mV
7.5 mA 26.10mV
14.5 mA

1.0 mA 0.00mV
8.0 mA 27.55mV
15.0 mA

1.5 mA 0.00mV
8.5 mA 28.34mV
15.5 mA

2.0 mA