566 



DISEASES OF THE MAMMARY GLANDS. 



VlCa 



G-.HM. 



sinus, is extremely rich in elastic filn-es, enabling the organ to inidergo 



great changes in volume without injury. 



Vessels.— The mammae are supplied by two great arteries, the 



mammary arteries, which are given off from the prepubic arteries, pass 



into the inguinal canal, and penetrate the gland hy its upper, deep face. 



Each principal lateral artery divides into two trunks, one for the 



anterior, the other for the posterior quarter. 



The veins which collect the blood from the mammae form two 



systems, the first accompanying the mammary arteries, the second, 



more superficial, 

 J -g giving rise to the 



anterior sub- 

 abdominal mam- 

 mary veins. The 

 arterio- venous 

 plexus of the 

 udder, which re- 

 presents the vas- 

 cular pedicle of the 

 organ, penetrates 

 the gland, near a 

 line dividing the 

 posterior and 

 middle thirds of 

 the upper surface, 

 an inch or so in 

 front of the mam- 

 mary lymphatic 

 gland. 



Lymphatics.— 

 On either side of 

 the middle line lies 



an extremely rich lymphatic plexus, the origin of which is to be found 



near the ends of the teats and in the peri-acinous spaces. 



The superficial collecting vessels are dispersed under the skin, 



perforate the fibrous sheath towards the base of the teat, and anastomose 



with one another on the surface of the gland, the anastomosis being 



most intimate between those of the same quarter, finally emptying 



separately by two large trunks into the retro-mammary lymphatic gland 



of the same side. 



The vessels of the anterior quarter enter the l^anphatic gland at 



its most anterior point ; those Of the posterior quarter join it a little 



below. 



Fig. 237. — Schema showing the structure and organisation of 

 the udder. Antero-posterior section showing the arrange- 

 ment of the anterior and posterior quarters and the teats, 

 skin, transverse partition, etc. GEM, Eetro-mammary 

 lymph gland ; Ljj. lymphatics of the posterior quarter ; 

 La, lymphatics of the anterior quarter ; LE, efferent lym- 

 phatics ; AM, mammary artery ; VM, mammary vein ; 

 VMrt, anterior mammary vein (subcutaneous abdominal 

 vein) ; C, transverse inter-mammary septum. 



