CHAPTER VIII 

 MUSCLE MOVEMENTS 



Structure of Muscle 



EXAMINE the muscles of the leg of a rabbit. They are of 

 various shapes, but are usually larger in the middle than at 

 either end. They are attached at both ends to bones, usually 

 by tendons. Remove a complete muscle from the limb. It can 

 readily be divided longitudinally into bundles, and these can 

 be split into smaller bundles, and these again by means of 

 needles may be frayed out, or teased as it is called, into a 

 number of fibres. 



Striated Muscular Tissue. Muscles which are larger 

 in the middle than at the ends are divided into a belly and 

 two extremities. The .belly is usually free, while the extremi- 

 ties are fixed by tendons, one to one bone and the other to 

 another, the muscle passing over at least one joint. 



The upper attachment or the attachment to the less mov- 

 able bone is called the origin of the muscle, and the lower 

 attachment or that to the more movable bone is called the 

 insertion. Sometimes there is more than one origin, the 

 muscle arising by two or more tendons ; and sometimes the 

 attachment extends down to the belly of the muscle by the 

 muscular fibres being attached to the bone without the inter- 

 vention of tendon. Sometimes also there is more than one 

 insertion. 



The longitudinal bundles into which the whole muscle may 

 be divided are called fasciculi. Each fasciculus is covered 

 with a thin sheath of connective tissue, and the several fasciculi 

 are connected together by connective tissue, which also forms 



