Subcutaneous cellular tissue.—On raising the integuments a layer of cellular substance is observed, not containing much fat. It is strong, coarse, and filamentous, and adheres to the skin more than to the muscles. In passing a seton in the neck we pinch it up with the skin, and transfix it without touching the muscles, which could not be wounded with impunity. Along the middle line this fascia is more con nected to the deeper parts than it is on either side, and especially in the dorsal region.
This cellular tissue is frequently the seat of post-mortem congestions and effusions arising from the gravitation of the fluids to so depen dent a position; hence we generally find it either very vascular or infiltrated with fluid, in a state quite resembling anasarca.
A very fine layer of cellular tissue, under neath this again, closely adheres to the mus cular fibre, and a good deal of motion may take place between these two layers.
The arteries which supply the skin and fascia in the neck are branches of the occipital, the cervicalis profunda, and the transversalis colli, to which the vertebral and transversalis humeri may contribute a little. In the dorsal region the posterior scapular and the dorsal branches of the intercostals principally supply these parts ; and in the lumbar region we have the posterior branches -- of the lumbar arteries. None of these approach the skin in their undi vided state, so that superficial wounds here can never be followed by troublesome haemorrhage. In the fascia we generally find a vein, described by Godman of Philadelphia under the name of the dorsal azygos. It arises at the lower part of the back by irregular roots, runs up single for some time along the middle line, and then divides into two branches, one of which pierces each trapezius, and enters into the transversalis colli vein. It is small and of
little importance. The other veins are not of sufficient size to deserve particular notice ; they are found in company with the arteries.
nerves of this region are the posterior branches of all the spinal nerves. The cervical and brachial plexuses also send some filaments ; but its nervous supply is, like its vascular, very scanty.
Lymphatics. —The lymphatics, too, are not so numerous as elsewhere. We trace them running to the cervical, axillary, and inguinal glands, according to their proximity to these. With the exception of two or three on the cer vical portion of the trapezius, lymphatic glands are not met with here.
The back is peculiarly subject to anthrax in debilitated constitutions, and in some cases the tumour acquires great magnitude. It some times happens that several anthraxes occur in succession, until a large portion of the integu ments and fascia is destroyed, and the patient sinks under the disease. Pressure is frequently the exciting cause. By pressure the vessels are so obstructed that the vitality of the part is impaired, and its organization is too low to enable it to recover from the deadening effects, especially if the constitution be previously in jured. Ilere too we often meet with furunculi they are most common in the nape of the neck. Fistula in the lumbar region, depending on diseased kidney, sometimes present themselves. There is no peculiarity in the cutaneous or other diseases to which it is liable in common with other regions.