Human body system
1. Compare the reaction times for voluntary vs. involuntary activation of the quadriceps muscle. What might account for the observed differences in reaction times? Outline what has to occur in the body for each reaction to occur. Refer to your drawing from Step 24. Information from the flow chart you created in Activity 2.2.1 might also be helpful.
The involuntary activation of the quadriceps muscle was faster than voluntary time; the reason could be that when you had to hear the sound for the voluntary activation you had to process the sound than process kicking. This would take longer than automatically kicking with the involuntary activation. In the body an impulse nerve signal had to be sent to the object reacting in this case kicking your leg.
2. How does your reaction time to the voluntary action of your quadriceps compare with your reaction time to the simple reaction task in Project 2.2.3? The task in this lab involved hearing a sound and reacting with your foot. The task in Project 2.2.3 involved seeing a signal and reacting with your finger. What do reaction times tell you about how these signals are processed?
The two reaction times compare by both processing information than reacting either with your finger or with kicking your foot. They both were pretty close times because you are doing close to the same thing. 3. Assume the speed of a nerve impulse is 100 m/s. How does this compare to the speed of electricity in a copper wire (approximately 3.00 x 108 m/s)? What does this tell you about the flow of electrons in a wire compared to the movement of ions in a membrane?
Electricity in a copper wire is faster than nerve impulse, this could be because an atom is bigger than an electron, and since electrons are smaller they can get through faster. In the wire there is just electrons flowing but in the nerve membrane there are proteins opening and closing which makes the nerve impulses move slower. 4. What do you think is the evolutionary significance of reflexes? Use an example to explain your reasoning.
The evolutionary significance of reflexes is that the spinal cord takes care of the reflexes making reacting time faster and quicker for you to do. 5.Suggest two ways that reflex reactions help maintain homoeostasis in the human body.
One way reflexes help maintain homoeostasis is if your cold your body tells you to move to somewhere warm or get a blanket. Another way is when the body detects changes in external/internal environment; the receptor will generate a nerve impulse to the coordination center and then make a response through effector. This is a reflex arc. 6. Explain how the accelerometer and the EMG electrodes work together to generate data on response time. How does the LabVIEW program help you analyze this data?
The accelerometer and the EMG electrodes worked together by 7. Using data from your reflex experiment, calculate the speed at which a stimulus traveled from the patellar tendon to the spinal cord and back to the quadriceps muscle (complete reflex arc). To do this, you must estimate the distance traveled. Using a cloth tape measure, measure the distance in cm from the mark on the patellar tendon to the spinal cord at waist level (straight across from the small of your back -see the figure on the next page). Multiply the distance by two to obtain the total distance traveled in the reflex arc. Once this value has been obtained, divide by the average time from the patellar reflex trial and divide by 100 to obtain the speed in m/s, at which the stimulus traveled. Show your work.
8. Nerve impulses have been found to travel as fast as 100 m/s. What could account for the difference between your answer to Question 7 and this value obtained by researchers?