View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector HISTOLOGY AND CYTOCHEMISTRY OF HUMAN SKIN. XIV. THE BLOOD SUPPLY OF THE CUTANEOUS GLANDS* RICHARD A. ELLIS, PH.D., WILLIAM MONTAGNA, Pn.D. AND HERBERT FANGER, M.D. Although the general blood supply to the skinout clearly against a nearly colorless background. has been mapped out in some detail (1), the exactIn thick frozen sections the entire capillary plexus vascular patterns of the human cutaneous ap-surrounding the cutaneous glands can frequently pendages need clarification. Other authors havebe seen as they emerge from their parent arteriole used injection methods, silver impregnation, and(Figs. 3, 6, 8). The endothelium of the arterioles benzidine to demonstrate the blood vessels of thehas practically no alkaline phosphatase activity, skin. None of these methods is completely satis-but enzyme activity becomes increasingly strong factory or practical in all cases. We have found,near the emergence of the capillaries and is in- however, that the capillaries supplying the skintense in the final capillary loops (9). Although it and the cutaneous appendages can be easilyis difficult to positively identify the arterioles and visualized in frozen sections with the azo-dyevenules in these preparations, recent observations technic for alkaline phosphatase (Fig. 1). Thisin our laboratory on the localization of phos- method is superior to the others used. It is simple,phorylase activity in human skin make the identi- quasi-specific, and demonstrates clearly even col-fication of arterioles easy, since the smooth mus- lapsed or blocked capillaries. Using this techniccle cells around them are rich in this enzyme (Fig. Montagna and Ellis (9) have studied the vascular2). The arterioles demonstrated with the phos- patterns surrounding active and quiescent humanphorylase technic are identical with the larger hair follicles, and are now studying the effects ofvessels visualized with the alkaline phosphatase aging on the vascularity of the skin. The currenttechnic (Figs. 2, 8). report presents only our observations on the The vascular bed around each of the three blood vessels of the sweat glands and sebaceoustypes of cutaneous glands will be described glands. separately. These descriptions are a general sum- mation of all the material studied, but a few MATERIALS AND METHODS vascular changes that occur during aging are This investigation is based on 77 specimens ofalso briefly reported. These will be dealt with in skin removed during surgery and from cadaversdetail in another paper. dead not longer than four hours. Specimens taken The patterns of the blood vessels of the skin from all the representative regions of the bodyhave been reviewed in general terms by Horst- were obtained from 34 subjects, aged 9 months tomann (5). He states that the vascular nets around 78 years. All of the tissues were presumablythe hair follicles and sebaceous glands originate as normal. side branches from any level of the candelabra The technic for the demonstration of alkalinearterias. These arteries spring from the deeper phosphatase activity in frozen sections is thatdermal plexuses and go straight to the surface, outlined by Gomori (4). The particular way inwhere they branch out at once, giving the ap- which the method is handled has been describedpearance of an inverted candelabrum. The eccrine by Montagna and Ellis (9) and is used in thissweat glands are vascularized by branches from study without modification. both the candelabra arteries and the cutaneous plexus. Horstmann (5) gives no information on OBSERVATIONS the blood vessels of the apocrine sweat glands, or Human skin has so little alkaline phosphataseon the relationships between the cutaneous glands activity that the endothelium of capillaries standsand their capillaries. *Fromthe Department of Biology, Brown THE SEBACEOUS GLANDS University and Department of Pathology, Rhode Island Hospital, Providence, Rhode Island. The small sebaceous glands, such as those This work was supported in part by a grant fromfound in the scalp of young people, are invested the United States Public Health Service, RG 2125 C7 with a network of capillaries that generally arises Received for publication October 9, 1957. from one of the arterioles associated with vascular 137 138 THEJOURNAL OF INVESTIGATIVE DERMATOLOGY nets of the hair follicles (Fig. 3). The nets aroundis accompanied by one or more capillaries or ar- each glandular acinus is formed by the bifurcationterioles that wind loosely about it as it courses of capillary twigs and by cross-shunts betweentoward the epidermis (Fig. 1). These vessels are the capillaries. The capillaries assunìe more intri-all connected by cross-shunts that form a loose cate patterns around the larger and more complexplexus or lattice along the duct. The straight sebaccous glands. More or less evenly spacedvessels branch at the level of the subpapillary vessels follow the contours of the gland; theyplexus and send capillary loops underneath the penetrate the delicate septa of connective tissueepidermis. These vessels outline a cone around that separate the lobes and lobules of the glandthe epidermis that surrounds the eccrine sweat (Fig. 4); in some tissue sections the vessels seemgland unit. Near the surface of the skin the eecrine to be penetrating the sebaceous acini or lyingduct may also be supplied with capillary branches within the sebaceous gland. In specimens of skinfrom the arcades of vessels that lie under the from aged subjects, the capillaries supplying aepidermis. single sebaceous gland may be derived from a Although obvious changes occur in the sweat number of arterioles. In bald scalp, together withducts during ageing, the vascular beds around the retrograde metamorphosis of the hair folliclesthem remain almost unaltered. to vellus types, the schaceous glands undergo a prodigious increase in size. The follicles of vellus APOCRINE 5WEAT GLANn5 hairs are supplied by a vestige of capillary nets, As examples of apoerine sweat glands we have while the sebaceous glands seem to usurp theexamined the axillary organ and the external capillaries that were once around the largerauditory meatus. In the secretory coils of these parent follicle (Fig. 5). With ageing there is anglands a considerable amount of alkaline phos- increasing disorganization of the blood vascularphatase activity is concentrated mostly in the system of the skin and these changes are reflectedmyoepithelial cells. The ducts of these glands in the vascularization of the sebaceous glands. have no enzyme activity. The capillaries supplying apocrine sweat glands ECCEINE SWEAT GLANn5 emerge from arterioles that are often seen in these Human eccrine sweat glands consist of threepreparations. The capillaries form elaborate sys- segments: (1) a glomerate deep portion consistingtems of loops and interconnecting branches, hi- of the secretory coil and the coiled duct; (2) afurcations and cross-shunts around the tubules straight dermal sweat duct; and (3) a spiral(Fig. 8). These vessels adhere to the surfaces of within the epidermis called the epidermal sweatthe tubules but they are never seen penetrating duct unit. The deeper coils of the glomerate parttheir surface. There is no apparent difference in of the glands are the secretory portions, rich inthe blood supply to the dilated or the constricted alkaline phosphatase activity; the superficial coilssegments of the tubules; each is supplied with an are a part of the duct and are lacking in phospha-equal number of capillaries. A few capillaries tase (Figs. 1, 6). Myoepithelial cells, which con-follow the duct of the apocrine gland to its junc- tain small amounts of alkaline phosphatase, in-tion with the pilary canal. vest only the secretory coil. The capillaries that surround the secretory and CIRCULATORY RELATIONSHIPS the coiled portion of the dermal sweat gland duct Although they are seldom observed in skin frequently originate from the same vessel (Fig.specimens of young subjects, capillaries that con- 6); in large eecrine glands, however, the capil-nect the vascular beds of the various structures of laries may arise from several arterioles. In thethe skin are frequently seen in adults, and are scrotum, where the ecerine sweat glands arecommon in the aged. Capillaries joining the loosely coiled, the capillaries can be seen followingvascular system of eecrine sweat glands with the different loops of the tubule, and giving offthose around vellus hair follicles are often seen branches and shunts connecting the vessels(Fig. 9). Interconnecting capillaries are always around adjacent loops (Fig. 7). In tightly coiledpresent between the sebaeeous gland and the tubules, as for example in the arm (Fig. 1), orhair follicle, or between the sebaceous gland and axilla, this pattern is compressed and multiplied.the apocrine sweat glands. Vessels that are pri- The straight portion of the dermal sweat ductmarily associated with the epidermis often invest HISTOLOGY AND CYTOCHEMISTRY OF HUMAN SKIN. XIV 139 the terminal portion of the duets of eeerine sweatalso been studied by Eichner (3), using a silver glands or hair follicles. The exception is found inimpregnation method and iron hematoxylin, but the axilla, where regardless of the fact that thehis results were less satisfactory than ours. Re nests of eccrine and apocrine sweat glands arefound in the upper part of the knot of the gland crowded together, their individual capillary bedsan arteriole that runs