STUDY OF THE MUSCLEB. 63 



2. Place the tips of the fingers of the left hand 



at the lower end of the belly of the right 

 biceps muscle and the thumb at its up- 

 per end. Flex and extend the right fore- 

 arm several times. What change takes 

 place in the length of the muscle ? 



3. Enumerate, therefore, three changes you 



have found to take place in the belly of 

 a muscle when it contracts. 



4. Roll the sleeve above the biceps muscle. 



Let the arm hang free, and with a tape- 

 measure get the circumference of the 

 upper arm around the middle of the belly 

 of the biceps muscle. Flex the forearm 

 as strongly as you can and then deter- 

 mine the circumference. What is the 

 amount of increase in size ? 



5. With the thumb and forefinger of the left 



hand grasp the tendon at the lower end 

 of the right biceps muscle; rotate the 

 right forearm. To which of the bones 

 of the forearm, therefore, is the biceps 

 attached? Point out on the skeleton 

 the rough prominence where the tendon 

 is attached to this bone. 



6. (Dem.) Demonstrate on the shoulder-blade 



the point of attachment of each of the 

 two upper tendons of the biceps. 



7. Which tendon (upper or lower) of the bi- 



ceps moves the more when you lift a 

 book? Which end is, therefore, origin, 

 and which insertion? Locate the belly 



