270 



PHYSIOLOGY AND HEALTH. 



Fm. LIII. 



Some are circular, as those that close the mouth and eye, 

 (Fig. LIT. 6, e.) The heart has no attachments ; it is sus- 

 pended in the chest, and acts only on its contents. The 

 muscular coat of the ossophagus, stomach, and alimentary 

 canal surrounds these organs, and, by its contractions, it 

 forces their contents onward. 



625. The muscles are not placed 

 directly between the bones which are 

 to be moved, this would make the 

 joints clumsy, but at some little dis- 

 tance, and attached directly at one 

 end to one bone, and then generall-y 

 fastened to a tendon or cord which 

 moves over the joint to the other bone. 

 The muscle that bends the elbow (Fig. 

 LIV. d) is placed entirely on the front 

 part of the upper arm. The upper end 

 of this is fixed to the upper bone, but no 

 part of the muscle touches the lower 

 'arm. A cord passes from the lower 

 end, over the elbow-joint, to the lower 

 arm. So, also, the muscles that move 

 the hand, the knee, the foot, &,c. 

 Sometimes the muscle is placed at a 

 considerable distance from the bone 

 to be moved. The muscles of the 

 fingers are placed, not on the hand, 

 nor even on the wrist, but on the 

 fore-arm, (Fig. LIII. , a, a;) and 

 the long cords or tendons (b, b, b) 

 can be easily felt as they pass along 

 the lower part of the fore-arm, and 



over the wrist, and over the hand to 



a, a, a. The fleshy parts 



of the muscles. tne fingers. By a similar arrange- 



b, b, b. Tendons of these ment, the toes are moved by muscles 

 muscles passing over the situated on the leg. The cords pass 

 wrist to the hand and fin- through groO ves or pulleys at the 



