228 ANATOMY AND PHYSIOLOGY 



of the nipple and areola of the two sides communicate with each 

 other. 



SUMMARY AND FUNCTIONS 



The right lymphatic duct gathers lymph from the right upper 

 extremity, right head, neck, thorax and thoracic viscera, and the 

 upper surface of the liver. 



The thoracic duct gathers lymph from all other parts of the 

 body that is, the left side above the diaphragm, and all parts 

 below the diaphragm, except the upper surface of the liver. The 

 two ducts empty into the two subclavian veins, and thus the lymph 

 joins the blood current. 



The Flow of the Lymph Stream. This is maintained by the 

 same forces which are concerned in the flow of blood in the veins 

 (i) the aspiration of the thorax; (2) the intermittent pressure and 

 relaxation of surrounding muscles throughout the body; (3) the 

 constantly lowering resistance in front of the stream as the vessels 

 grow larger; (4) probably by the action of muscle-fibers in the walls 

 of lymph vessels and the assistance of the numerous valves, by 

 which they hold what they receive, never allowing the stream to 

 fall back. Add to these general forces the special influence of 

 the peristaltic movements of the alimentary tract; these must 

 cause a rhythmic closing and opening of the lymph vessels which 

 are the most active of any in the body, and in consequence, a large 

 volume of lymph containing the products of digestion, is set in 

 motion. 



Clinical notes. Certain conditions of disease in an organ or tissue are 

 followed by enlargement of the nearest glands which receive lymph from that 

 part. If the disease be not arrested, the glands next in order will suffer, and 

 the next, and the next. 



Disease of the mammary gland will cause swelling, first, of the superficial 

 glands under the border of the pectoral muscle, and later of the deep axillary 

 and clavicular glands. Mediastinal glands are sometimes affected when the 

 upper portion of the gland is diseased. 



Disease of the tonsils will affect the submaxillary and cervical glands. 



Disease of the pharynx, the cervical glands. 



Disease of the larynx will affect the cervical glands, and may affect the 

 mediastinal and bronchial glands. 



Disease of the upper extremity will cause swelling of the axillary glands. 



Disease of the lower extremity will affect the saphenous group and the 

 inguinal. 



