EFFECTS OF MUSCtTLAR EXERCISE* 



treme parts, and in the veins from the latter towards 

 the heart, with greater force and velocity than before. 

 This will be better understood on 

 examining the annexed engraving 

 of the blood-vessels of the arm, 

 . copied "Trom Fyfe's Anatomy. 

 The letters A, B, C, D, E, repre- 

 sent the principal muscles of the 

 arm; and F, G, H, I, K, M, N, 

 those of the forearm ; but as the 

 preparation is dried, and the mus- 

 cles consequently much shrunk, 

 they do not appear in their natural 

 situation. The letters in italics 

 refer to the humeral artery, which 

 is seen dividing at the elbow into 

 two branches. The one, called 

 the radial artery, passes on the 

 outer side of the forearm towards 

 the thumb, and is the branch in 

 which the pulse is generally felt ; 

 the other, called the ulnar^ passes 

 along the inner side of the fore- 

 arm. 



In the natural state, these blood- 

 vessels are covered and protected 

 in almost their whole course by 

 the adjacent muscles. In conse- 

 quence of this position, the mus- 

 cles cannot contract without at 

 the same time compressing the blood-vessels, and 

 propelling their contents. The assistance afforded 

 to the circulation of the blood by this arrangement 

 is familiarly exemplified in the operation of blood- 

 letting from the arm. When the blood stops or 

 flows slowly, it is customary to put a ball or other 

 hard body into the hand of the patient, and desire him 

 to squeeze and roll it about. The success of this 

 action depends simply on the muscles of the arm 



