You are getting ready to leave the lab You lift your pencil

You are getting ready to leave the lab. You lift your pencil to put it in your book bag. Then, you lift your lab book and place it in your book bag. Which scenario resulted from the stimulation of more motor units? _____ Why? _____ Which would require more neural signals being sent by the nervous system to the muscles of your arms? _____ Why? _____ What concept covered in this lab (threshold, recruitment, or maximum contraction) explains why there are certain objects that are too heavy for you to lift? _____ Explain your reasoning.

Solution

13) @) lifting a book will result from the more number of motor neurons.. As the work of lifting a book is more I means more impulse..

(b) nervous of more work will be book will be more than pen.. The number of muscle fibers within each unit can vary within a particular muscle and even more from muscle to muscle; the muscles that act on the largest body masses have motor units that contain more muscle fibers, whereas smaller muscles contain fewer muscle fibers in each motor unit..