30 



VETERINARY STUDIES 



side of the body, and also one or more opposing muscles on its 

 own side. 



The belly of a muscle has a rich blood supply ; the tendon has 

 very little. 



A muscle produces motion by pulling upon some bone which 

 acts as a lever with the fulcrum at a joint. 



The muscle fibers may attach directly to the bone, or indirectly 

 through tendon fibers. The connection between the muscle 

 fiber and the tendon fiber is by insertion of the conical point of 



Fig. 16. — ^^"oluntary Muscle. {M. H. E.) 



1. Action of Muscle in Producing Motion. Muscle does its work by 

 shortening its belly. A, A, bones; B, B, tendons; C, belly of muscle; E, 

 articulation (joint). 



2. Muscle in Cross Section. Showing "bundle of bundles" arrangement 

 of the fibers. Dots represent single fibers. 



3. Diagram of Simj^le Muscle. B, B, tendons; C, belly (lean meat). 



the muscle fiber into a conical cavity at the end of the tendon 

 fiber. 



Structure. — The voluntary muscle consists of bundles of 

 bundled fibers ; each individual fiber has its own delicate sheath. 

 A number of fibers are inclosed within a common connective 

 tissue sheath and constitute a minute bundle. A number of 

 these bundles are in turn wrapped within a connective tissue 

 sheath, forming a larger bundle. These larger bundles may in 

 turn be wrapped by means of another connective tissue sheath 

 into a still larger bundle. 



The voluntary muscle fiber is long, threadlike, marked by 

 cross stripes which are very close together, and may end in 

 tendon fiber. These muscle fibers are about 1/1500 of an inch 

 wide, but may be very long — one inch or less. 



