HISTOLOGICAL STUDIES 



45 



(Note in the three classes of connective tissue that the 

 intercellular portion is the important part in support. The 

 importance of the cells becomes clear when it is understood 

 that this intercellular matrix is produced by them.) 



XXVII. MUSCULAR TISSUE (OPTIONAL). 



Apparatus. Prepared slides of striated and non-striated muscle, 

 compound microscope. 



Directions. A. Non-striated. Note the long, spindle- 

 shaped cells, the elongated nucleus, and the homogeneous 

 protoplasm filling the whole 

 cell. Note, further, how 

 these cells interlace. (They FlG - 19. A Non-striated Muscle Ceil: n, 



nucleus. 



are held together by a ho- 

 mogeneous cement substance.) Note the absence of any 

 stria tion, or striping. Draw several of these cells under 

 the high power, locating all the parts mentioned above. 



B. Striated. Examine a single fiber with the high power. 

 Note the broad, dim, transverse strise 

 and the narrow, light, transverse strise. 

 The broad stria is called anisotropic or 

 doubly refracting, contractile sarcoplasm. 

 The narrow stria is called isotropic or 

 singly refracting sarcoplasm. Note also the 

 more or less dim longitudinal striation. 

 Over the whole of the fiber is stretched the 

 transparent sarcolemma, or cell wall. Some- 

 where on the fiber may be found also sev- 

 eral nuclei. Draw and locate all these parts of the muscle 

 cell. (Sarcoplasm is merely another name for the protoplasm 

 of a muscle cell.) 



FIG. 20. Portions of 

 Striated Muscle 

 Fibers. (The figure 

 shows the striae and 

 the nuclei.) 



