45 

 THE BLOOD AND LYMPH VASCULAR SYSTEM. 



LABORATORY WORK FOR THE WEEK. 



References : 

 Points for Quiz : 



Laboratory Report : 



Due . 



Obtain from the delivery desk (a) assigned slide, 85 ; (d) 

 paraflSn sections, 83, 84, 86, 92, 94 ; (c) collodion sections, 91, 95 ; 

 (rf) 93, already stained. 



ARTERIES. 



83. Muscular artery. Cow. Transection of the uterine 

 artery. Zenker's fluid (§ 28) ; paraffin ; sections fx. Stain 

 with hematoxylin 30 minutes, picrofuchsin 30 seconds. 



In this preparation identify the three coats forming the walls of 

 arteries and veins, — the intima, media and adventitia ; noting the 

 relative thickness of each. In the intima, recognize the vascular 

 epithelium, the internal elastic membrane, and the subepithelial 

 connective tissue. In the media should be found, plain muscle cells, 

 elastic bands and white connective tissue ; recall the staining reac- 

 tions of picrofuchsin (used for this preparation) with muscle, white 

 and elastic connective tissue. Are there longitudinal muscular 

 bundles present ? Note the relative amounts of white and elastic 

 tissue. In the adventitia, observe the relative amounts and arrange- 

 ment of the white and yellow elastic fibers. Is an external elastic 

 membrane present ? 



84. Elastic artery. Transection of the carotid 

 artery. ; paraffin ; sections yu. Stain with 

 hematoxylin minutes, picrofuchsin seconds. 



Compare this preparation with 83, recognizing the coats, their 

 relative thickness and structure. Especially compare the media in 

 the two preparations, noting the relative amounts of muscle and 

 elastic tissue in each. 



