40 



cut ends, due to the transected fibrillae, and the muscle nuclei entad 

 of the sarcolemma. Can you recognize areas of Cohnheim ? The 

 transections of the fibers are of different sizes. This may or may 

 not mean a difference in the caliber of the fibers. Why ? Compare 

 with 61. You may be shown transections stained with iron hema- 

 toxylin in which the fibrillae are better differentiated. 



CARDIAC MUSCLE. 



68. Muscle cells. Isolated in caustic 

 potash dissociator ( 14) ; now in glycerin. Place a small drop of 

 the glycerin containing the cells upon the slide ; cover carefully ; 

 seal with shellac. 



Study the preparation, examining many cells and noting the 

 shape, the position of the nucleus or nuclei, the trans-striations, the 

 relation of the cells to each other, and their processes. 



69. Transection of myocardium. Human auricle or ven- 

 . tricle. Assigned for study. Miiller's fluid ; paraffin ; sections 



10 /*. Stained with hematoxylin and picrofuchsin. 



Observe the shape and relation of the cells, the muscle columns 

 and fibrillae, and the position of the nucleus ; compare with the 

 transections of plain and striated muscle (61, 67). You may be 

 shown transections and longisections of cardiac muscle stained with 

 iron hematoxylin, in which the fibrillae and cross-striations are bet- 

 TOPICS FOR QUIZ loth Week. 



THE MUSCULAR TISSUES ; THE MUSCULAR SYSTEM. 



1. Muscular tissues, variety and characteristics of each ? 



2. Plain muscle cells, structure? <^ 



3. Compare the muscle in an artery and that in the intestine. 



4. Name five regions of distribution of plain muscle. 



5. Give relative length and width of muscle cells in arteries. 



6. Compare plain muscle in transections and in longisections. 



7. How, distinguish plain muscle from connective tissue? 



8. Stilted muscle ; structure of a muscle fiber, considering sarcolemma, 

 muscle nuclei, sarcoplasm and fibrils? 



9. Give the structure of the fibrillae and the various discs. 



10. What is the structure of a skeletal muscle, fasciculi, epi- peri- and endo- 

 mysium. 



11. What is the position of muscle nuclei in mammalian and immammalian 

 muscle ? Best determined by transactions. 



