The diaphragm in man : a record of our present knowledge of its development, relationships, structure, and mode of action / by J.F. Halls Dally.

Dally, John Frederick Halls, 1877-1944.

Date:: [1908?]

Credit: The diaphragm in man : a record of our present knowledge of its development, relationships, structure, and mode of action / by J.F. Halls Dally. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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$1^4 The I)iaj)hra(jm in ]\[an. system of modified veins which liave no connection with the connective-tissue spaces or large serous cavities. Notwith- standing that the openings “are far from representing per- manently open channels of communication between the serous cavities and the vessels ” in places, probably, nothing is interposed beyond the endothelium of the lymphatic on the one side, and the endothelium of the serous cavity on the other. Muscatello (^®) believes that leucocytes, after ingesting particles, force their way through the membrane, being imme- diately followed by a rush of free particles, which continues until the space again closes. Muscatello’s opinions are con- firmed by the experiments of MacCallum with particles of carmine and Indian ink. This observer describes two endo- thelial layers with very thin basement membrane between, the lymphatics at these points being dilated into lacuna3. He assigns the chief role in the transmission of particles to the phagocytes—chiefly polynuclear leucocytes—and a lesser part to the pumping action of the diaphragm, which is said to force particles between the lining cells from the peritoneal cavity to the lymphatic lacunae. The experiments of Buxton and Torrey show that absorption from the peritoneal cavity takes place mainly by the anterior mediastinal route, most if not all of the conveyed particles lodging in the anterior medias- tinal lymph nodes, of which the most prominent and constant are an upper pair (often three) situated in the first intercostal space. Other lower, less important pairs often are found in the third or fourth intercostal spaces. These nodes act as filters for the diaphragmatic lymph vessels which drain the peritoneal cavity. “ Large bacilli, such as anthrax, can be absorbed through the diaphragm of a guinea-pig and reach the anterior mediastinal nodes in fifteen minutes or less” (^“). Staphylococci and typhoid bacilli can also readily be absorbed through the diaphragm. The lymphatics of the crura drain into the lumbar glands. ]i\—The Means of Suppoht of the DiAniiiAGM. These may be divided into superior or thoracic, and inferior or abdominal:— A. Siq^erior or Thoracic Supports of the Diaj)hrarjm.—The peri- cardium, as the name denotes, is the sac which surrounds the heart. Yet this office of investment is but one of the two distinct functions respectively corresponding to its two component layers. By its internal serous layer it is reflected upon the heart, and, diminishing friction by means of its apposed smooth and lubricated visceral and$