SECRETING GLANDS 



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Secreting Glands. The secreting glands present, amid manifold 

 diversities of form and composition, a general plan of structure; but all are 

 constructed with particular regard to the arrangement of the cells which has 

 just been described. 



Secreting glands are classified according to certain structural types, as: 

 i. The simple tubular gland, A, figure 247, examples of which are furnished 

 by the follicles of Lieberkiihn, and the tubular peptic glands of the stomach. 



FIG. 247. -Plans of Extension of Secreting Membrane by Inversion or Recession in the Forms of 

 Cavities. A, Simple glands, viz., g, straight tube; h, sac; i, coiled tube. B, Multilocular crypts: 

 k, of tubular form; /, saccular. C, Racemose or saccular compound gland : m, entire gland, show- 

 ing branched duct and lobular structure; n, a lobule, detached with o, branch of duct proceeding 

 from it. D, Compound tubular gland. (Sharpey.) 



They are simple tubes of mucous membrane, the walls of which are lined with 

 secreting cells arranged as an epithelium. To the same class may be referred 

 the elongated and tortuous sudoriferous glands. 



2. The compound tubular glands, D, figure 247, form another division. 

 These consist of main gland tubes, which divide and subdivide. Each gland 

 may be made up of the subdivisions of one or more main tubes. The ulti- 



