A STUDY OF BLOOD MANUFACTURE 



83 



Two other pairs of glands, the sub-max'il-la-ry (Latin 

 sub = beneath + maxilla = jawbone), and the sub-lin'gual 

 (Latin sub = beneath + lingua = tongue), lie in the muscu- 

 lar floor of the mouth cavity, and the ducts from these 

 glands open in the floor of the mouth under the tongue. 



Microscopic Structure of Salivary Glands. Each of the 

 salivary glands, when dissected and examined with the 

 microscope, reminds one of a 

 bunch of grapes, and for this 

 reason this type of gland is 

 called rac'e-mose (Latin race- 

 mosus = full of clusters). The 

 principal duct of the gland 

 may be compared to the main 

 stem of the grape cluster, and 

 connected with this duct are 

 the small ductules (Latin duc- 

 tus= pipe + ulus = little) which 

 answer to the small grape 

 stems. At the end of the 

 ductules are the tiny hollow 

 spheres or gland recesses (re- 

 sembling grapes in form), the 

 cells of which secrete the sa- 

 liva. All parts of the gland 

 are surrounded and held to- 

 gether by fibers of connective 



tissue. Blood vessels bring to the gland cells the raw mate- 

 rials from which the saliva is produced. The workings of 

 the gland are largely controlled by nerve fibers that run 

 from the brain. 



In brief, then, the essential elements of the salivary glands, 

 or of any other glands, are the special gland cells, the blood 

 vessels, and the nerves. 



Uses of Saliva. (1) The saliva aids the mucus in keeping 

 the mouth moist, and thus we are enabled to talk easily. 



FIG. 28. Dissection to show the 

 Salivary Glands. 



a = sublingual gland. 

 b = submaxillary gland, 

 c = parotid gland. 

 d = ducts from sublingual and sub- 

 maxillary glands. 

 e = duct from parotid gland. 



