The general relations which the larger vessels of the inguino-femoral region bear to each other and to the superficies, may be referred to in PLATE 27, with practical advantage. The umbilicus, A, indicates pretty generally the level at which the aorta bifurcates on the forepart of the lumbar vertebrae. In the erect, and even in the recumbent posture, the aorta may (especially in emaciated subjects) be felt pulsating under the pressure of the hand; for the vertebrae bear forward the vessel to a level nearly equal with, C C, the anterior superior spinous processes of the iliac bones. If a gunshot were to pass through the abdomen, transversely, from these points, and through B, it would penetrate the aorta at its bifurcation. The line A B coincides with the linea alba. The oblique lines, A D, A D,* indicate the course of the iliac vessels. The point D marks the situation where the spermatic vessels enter the abdomen; and also where the epigastric artery is given off from the external iliac. The most convenient line of incision that can be made for reaching the situation of either of the iliac arteries, is that which ranges from C, the iliac spine, to D, the point where the spermatic cord enters the abdomen. The direct line drawn between D and G marks the course of the femoral artery, and this ranges along the outer border, E, of the saphenous opening.
DESCRIPTION OF PLATE 27.
A. The umbilicus.
B. The upper margin of the pubic symphysis.
C. The anterior superior spine of the left iliac bone. C*, the situation iof the corresponding part on the right side.
D. The point where, in this subject, the cord manifested itself beneath ithe fibres of the external oblique muscle. D*, a corresponding part on ithe opposite side.
E. The saphenous opening in the fascia lata, receiving e, the saphenous ivein.
F. The lax and pendulous cord, which in this case, overlies the upper ipart of the saphenous opening.
G. Lymphatic glands lying on the fascia lata in the neighbourhood of the isaphenous opening.
H. The fleshy part of the external oblique muscle.