54 



ANATOMY AND PHYSIOLOGY FOR NURSES 



The muscles are capable of shortening when irritated 

 mechanically or by nerve-stimulus, this property being 

 called "muscular contractility or irritability." 



When a muscle is attached to bone or cartilage, the 

 fibers terminate in broad, blunt extremities upon the 



FIG. 30. Voluntary muscle: A, Three voluntary fibers in long sections : 

 a, Three voluntary muscle-fibers ; b, nuclei of same ; c, fibrous tissue be- 

 tween the fibers (endomysium) ; d t fibers separated into sarcostyles. B, 

 Fiber (diagrammatic): a, Dark band; b, light band; c, median line of 

 Hensen ; d, membrane of Krause ; e, sarcolemma ; f, nucleus. C: a, Light 

 band ; 6, dark band ; c, contracting elements ; d, row of dots composing the 

 membrane of Krause ; e, slight narrowing of contracting element aiding in 

 production of median line of Hensen (Leroy). 



periosteum or perichondrium, and do not come into direct 

 relation with the osseous or cartilaginous tissue. When 

 muscles are connected with the skin, they either lie. as a 

 flattened layer beneath it, or are connected with its areo- 

 lar tissue by larger or smaller bundles of fibers, as in the 

 muscles of the face. 



