MAMMARY GLANDS. 



249 



mary, and there is generally a large vessel 

 entering the pectoral or costal surface of the 

 breast and sending its branches through the 

 gland to meet the others upon the surface of 

 the organ. The branches from the axillary are 

 given off by the superior and long thoracic 

 arteries ; those from the internal mammary are 

 either derived directly from that vessel or from 

 its intercostal branches. " The arteries upon 

 the cutaneous surface of the breast are lodged 

 in the festoons formed by the ligamenta sus- 

 pensoria, and proceed to the nipple. There 

 their extreme branches pass each other at the 

 base of the nipple. They send branches for- 

 wards from the base to the apex of the nipple, 

 which are parallel to each other and divide into 

 very minute branches which supply the papillae 

 and the ducts. They also send branches from 

 the base of the nipple backwards into the 

 gland at its centre, and they freely anastomose 

 with those arteries which enter the back of the 

 gland, and they then distribute their ramifica- 

 tions to its substance." 



Veins. " The branches of the veins arising 

 from the nipple pass from its papillae in parallel 

 branches to its base, and then form radii to an 

 ellipse behind the areola at its margin." Their 

 minute divisions in the papillae with the cor- 

 responding divisions of the artery constitute 

 the erectile tissues. From the ellipsis of veins 

 four principal branches proceed, beside others 

 which are less important : these are distri- 

 buted on the fore part of the breast, forming a 

 net-work by their free anastomoses. 



They terminate, 1st, by two large branches 

 in the axillary vein, and by several branches in 

 the vein accompanying the arteria thoracica 

 longa; 2d, in the cephalic; 3d, in the internal 

 mammary vein by branches which pass between 

 either the first and second or the second and 

 third ribs: 4th, by a deep-seated vein which 

 enters the fourth mammary intercostal vein ; 

 5th, a plexus of veins passes over the clavicle 

 to terminate in the external jugular and sub- 

 clavian veins. 



Nerves. These are derived from the dorsal 

 division of the spinal cord. The third dorsal 

 nerve descends upon the vessels which are distri- 

 buted to the nipple and gland, the fourth and 

 fifth are distributed directly to the breast, and 

 the sixth sends some filaments upon the extre- 

 mities of those arteries which have passed the 

 nipple, but which send branches into the gland. 

 It also receives a supply from the grand sym- 

 pathetic nerve. 



Absorbents. These vessels are described by 

 Sir Astley Cooper as follows : ' 



" These vessels always exist in great numbers 

 in the breast, and when the gland is in a state 

 of lactation they are readily injected and 

 demonstrated. 



" They are divided into a superficial and 

 deep-seated order. The first are cutaneous 

 and are most connected with the nipple and 

 the mucous glands of the skin, arid the second 

 arise from the interior of the glandular and 

 secretory structure of the mamma. 



" The superficial arise from the nipple, 



and they pass principally upon the surface of 

 the gland, behind the skin, on its axillary 

 side. 



" In my injections I find them as follows : 



" First, they pass upon and then under the 



superficial fascia, and between it and the 



aponeurosis of the pectoral muscle. They are 



next continued over the intercostal muscles. 



" Here they enter the absorbent or cribriform 

 opening, or sometimes there are two openings 

 in the fascia axillae, as it there passes from the 

 edge of the pectoralis major to that of the teres 

 major and latissimus dorsi muscles, and which 

 fascia shuts up and forms the floor of the 

 axilla. 



" Having passed through this fascia into the 

 axilla they enter the first set of axillary absorb- 

 ent glands, and form a considerable plexus of 

 absorbent vessels between them. 



" They then rather descend to the third and 

 fourth ribs to enter another set of absorbent 

 glands, which are placed between the third and 

 fourth ribs and second and third intercostal 

 spaces, and they then ascend to the second 

 rib. 



" Here they form a large and elaborate 

 plexus upon the axillary vein, from one to two 

 inches below the clavicle, and reaching the first 

 rib they again enter absorbent glands. 



" 1-rom these glands, situated upon the first 

 rib, an absorbent trunk is formed, of the size of 

 a large crow-quill, which is placed close to the 

 inner side of the axillary vein and between the 

 first rib and the clavicle, and this absorbent 

 trunk terminates at the angle formed between 

 the right jugular and right subclavian vein, 

 where the absorbents of the right arm and those 

 of the right side of the neck also end in the 

 veins. 



" There is an opening formed for this vessel 

 under the costo-clavicular ligament with a 

 distinct margin on each side. 



" The place of termination of the absorbents 

 in the vein is a little above and behind a line 

 drawn from the middle of the clavicle above 

 the first rib. 



" On the left side the absorbents of the 

 breast form a similar absorbent trunk, which 

 terminates at the angle of the left jugular and 

 subclavian veins, at which angle the thoracic 

 duct also ends. 



" Besides this course of the absorbents from 

 the breast and through the axilla there are 

 other absorbent vessels which pass behind the 

 axillary vein, artery, and axillary plexus of 

 nerves to join the absorbents of the arm. They 

 also pass through several absorbent glands, and 

 ascending before the axillary plexus of nerves, 

 they mount behind the clavicle and before the 

 axillary bloodvessels, to terminate on each side 

 at the angle of the jugular and subclavian 

 veins. 



" Thus there are two courses of the absorbents 

 from the breast through the axilla; one internal 

 to the bloodvessels and between them and the 

 ribs ; the other, which is more external, joins 

 the absorbents of the arm, and passing behind 

 the vessels and nerves of the arm, then crosses 



