Lymphatic System

In the thorax are found intercostal glands (fig. 2), near the vertebral column draining the back of the thoracic walls and pleura; internal mammary glands, draining the front of the same parts as well as the inner part of the breast and the upper part of the abdominal wall; diaphragmatic glands, draining that struc ture and the convex surface of the liver ; anterior, middle, posterior and superior mediastinal glands, draining the contents of those cavities. The bronchial glands, draining the lungs, have already been referred to.

In the abdomen and pelvis the glands are usually grouped round the large arteries and are divided into visceral and parietal. Among the visceral are the gastric glands, draining the stomach (these are divided into coronary, subpyloric and retropyloric groups) ; the splenic glands at the hilum of the spleen, draining that organ, the tail of the pancreas and the fundus of the stom ach; the hepatic glands in the small omentum, draining the lower surface and deep parts of the liver; the pancreatic glands, behind the lesser sac of the peritoneum, draining the head and body of the pancreas; the superior mesenteric glands, from one to two hundred in number, lying in the mesentery and receiving the lacteals ; the ileo-caecal glands, draining the caecum, one of which is known as the appendicular gland and drains the vermiform ap pendix and right ovary; the colic glands along the right and mid dle colic arteries, draining the ascending and transverse colon; the inferior mesenteric glands in the course of that artery, drain ing the descending iliac and pelvic colons; the rectal glands, be hind the rectum, draining its upper part.

Among the parietal glands are the

external iliac glands, divided into a lateral and mesial set (fig. 2), and receiving the inguinal efferent vessels and lymphatics from the bladder, prostate, cervix uteri, upper part of the vagina, glans penis vel clitoridis and urethra. The supra and infra-umbilical glands receive the deep lymphatics of the abdominal wall, the former communicating with the liver, the latter with the bladder. From the latter, vessels pass to the epigastric gland lying in front of the termination of the external iliac artery. The internal iliac glands (fig. 2) are situated close to the branches of this artery and drain the rectum, vagina, prostate, urethra, buttock and perinaeum. Common iliac

glands lie around that artery and receive afferents from the ex ternal and internal iliac glands as well as a few from the pelvic viscera. (For further details of the pelvic glands see "Seventh Report of the Committee of Collective Investigation," Journ. Anat. and Phys., xxxii. 164.) The aortic glands are grouped all round the length of the aorta, and are divided into pre-, retro- and lateral aortic groups, all of which communicate freely. The upper preaortic glands are massed round the coeliac axis, and receive afferents from the gastric, hepatic, splenic and pancreatic glands; they are known as coeliac glands. The lateral aortic glands drain the kidney, adrenal, testis, ovary, fundus of uterus and lateral abdominal walls. In the upper extremity a few small glands are sometimes found near the deep arteries of the forearm. At the bend of the elbow are the ante-cubital glands (fig. I) and just above the internal condyle, one or two supra-trochlear glands (fig.

I). The

axillary glands (fig. I) are divided into four sets : (I) External, along the axillary vessels, draining the greater part of the arm; (2) anterior, behind the lower border of the pectoralis major muscle, draining the surface of the thorax including the breast and upper part of the abdomen; (3) posterior along the subscapular artery, draining the back and side of the trunk as low as the umbilical zone ; (4) superior or infra-clavicular glands, receiving the efferents of the former groups as well as lymphatics accompanying the cephalic vein. In the lower limb all the super ficial lymphatics pass up to the groin, where there are two sets of glands arranged like a T. The superficial femoral glands are the vertical ones, and are grouped round the internal saphenous vein; they are very large, drain the surface of the leg, and are usually in two parallel rows. The inguinal glands form the crossbar of the T (fig. I), and drain part of the buttock, the surface of the ab domen below the umbilicus and the surface of the genital organs. The deep lymphatics of the leg drain into the anterior tibial gland on that artery, the popliteal glands in that space, and the deep femoral glands surrounding the common femoral vein.