SWEAT GLANDS 



399 



fat. The product is eliminated through intra- and intercellular secretory 

 capillaries. It is ordinarily a fatty fluid for oiling the skin, but it becomes 

 the watery sweat under the influence of the nerves. The gland cells are 

 not destroyed by either form of activity. The secretory tubule is sur- 

 rounded by a distinct basement membrane, within which there is a row 

 of small longitudinally elongated cells described as muscle fibers. They 

 do not form a complete membrane, and they appear as a continuation of 

 the basal layer of cells of the ducts. 



Sweat glands are distributed over the entire skin, except that of the 

 glans and the inner layer of the praeputium penis. They are most numer- 

 ous in the palms and soles. In the axilla there are branched sweat glands 

 and large forms with 30 mm. of coiled tube. They acquire their large size 

 at puberty and have been considered as sexual "odoriferous" glands. In 

 the vicinity of the anus there are also branched sweat glands, together 

 with the large unbranched "circum-anal glands." 



A. Duct in 

 cross section. 



Nuclei of Muscle 

 gland cells, fibers. 



Membrana propria. 

 Cuticula. 



Muscle fibers 



B. Columnar epithelium 

 from the coiled tubule. 



C. Surface view 

 of the coiled tubule. 



D. Low epithelium from 

 a coiled tubule. 



Membrana propria. 



Muscle fibers. 



Muscle nucleus. 

 Cuticula. 



>.-^\l*/ Membrana propria 

 Muscle fiber. 



E. Cross section of 

 coiled tubule. 



FIG. 411. A-D, FROM A SECTION OF THE SKIN OF THE AXILLA; E, FROM THE FINGER TIP OF A MAN OF 

 TWENTY-THREE YEARS. X 230. E is not a true cross section. 



VESSELS AND NERVES or THE SKIN. 



The arteries proceed from a network above the fascia, and branch as 

 they ascend toward the surface of the skin. Their branches anastomose, 

 forming a cutaneous plexus in the lower portion of the corium. From 

 this plexus branches extend to the lobules of fat and to the coils of the 

 sweat glands, about which they form "baskets" of capillaries. Other 

 branches pass to the superficial part of the corium where they again anas- 

 tomose, forming a subpapillary plexus, before sending terminal arteries 

 into the papillae. The subpapillary plexus sends branches also to the 

 sebaceous glands and hair sheaths, but the papilla of a hair receives an 

 independent artery. The veins which receive the blood from the super- 

 ficial capillaries form a plexus immediately beneath the papillae, and 

 sometimes another just below the first and connected with it. The veins 

 from these plexuses accompany the arteries and the ducts of the sweat 



