Injuries and disease of the lymphatic system / by S. Messenger Bradley.

  • Samuel Messenger Bradley
Date:
1879
Catalogue details

Licence: Public Domain Mark

Credit: Injuries and disease of the lymphatic system / by S. Messenger Bradley. Source: Wellcome Collection.

    15/184 page 3
    head of a pin, others being equal in size to a filbert; they also vary in- size at different periods of life, being relatively largest in early life and smallest in old age. Their number varies likewise, sometimes as many as 700 have been counted, at others very much fewer are found. Some few are solitary, but the greater number are collected into groups ; they lie along the vessels of the neck, chest, and abdomen; a great number are found in the mesentery, a few smaller ones on the scalp, and congeries of considerable size in the axilla and groin, and to a less extent in the ham and elbow. The walls of the lymphatic vessels are so thin that the lymph can be seen through, and constrictions are observable at frequent intervals, which indicate the situation of valves, which like the valves of veins, are formed by two semilunar reduplications of the lining membrane. Structure of the lymphatic trunlis.—The lymphatic trunks closely resemble the veins in structure, but are thinner, and possess a more complicated arrangement of muscular fibres, which interlace very freely, like the fibres of the heart, and an endothelial lining, which differs from that of veins in presenting undulating serrated edges. We have, however, the three coats as in veins, the endothelial lining resting on a thin elastic layer, a middle muscular, and an external tunic of connective tissue. It was at one time believed that the blood-vessels com- municated directly with the lymphatics, because an injection often passed from the former into the latter, but it is now ascertained that no such communication exists, although the connection is so very close that the injection would readily make its way by slight rupture from one to the other. In the mesentery of the dog for instance we find lymphatic sheaths enveloping the blood-vessels, the vessels not being directly bathed in lymph, but surrounded with the lymph sheath, as the heart is with the pericardium, or the intestines with the peritoneum. Lymphatic capillaries.—Tlhe lymphatic capillaries, which are very numerous in the skin, in aponeuroses, on the surface of muscles and tendons, in the pericardium, pleura, diaphrao-m and all mucous membranes, possess no muscular fibres
    digitised image 1
    digitised image 2
    digitised image 3