OUR BODIES AND HOW WE LIVE 



67. The General Build of Voluntary Muscles. The vol- 

 untary muscles, although they seem to be solid masses of 

 red meat, really consist of separate bundles of flesh held 

 together by a very thin web of connective tissue, not 

 unlike the thinnest of tissue paper. Each bundle of flesh 

 is a muscle with its own set of blood vessels and nerves, 

 and is inclosed in its own sheath of connective tissue. 



68. How the Voluntary Muscles look under the Micro- 

 scope. If the tiniest bit of a voluntary muscle be examined 

 with the microscope, it is found to consist of bundles (fas- 

 ciculi) of separate fibers arranged side by side. Each sepa- 

 rate fiber is inclosed 

 in an elastic sheath 

 (sarcolemma) . 



These tiny fibers 

 are seen to be marked 

 crosswise with dark 

 stripes, and to be sepa- 

 rated at each stripe 

 into disks. 



On account of the 

 cross markings on the 

 fibers these muscles 

 are often called striped 

 or striated muscles 



}6. Blood Vessels in a Piece of Striped /Figs. 34 and 35). 



69. The Involun- 

 tary Muscles. The 

 involuntary muscles consist of ribbon-shaped bands which 

 surround hollow tubes or cavities in the body. They are 

 never attached to bony levers nor are they furnished with 

 tendons, as are the voluntary muscles. 



FIG. 



Muscle as seen under the Microscope. 

 Magnified 340 times. 



