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Show 1904.] CIRCULATORY SYSTEM IX THE OPIIIDIA. 349 transverse trunks with the fat-body ; posteriorly to the ovum the longitudinal artery of the fat-body is fed by branches of the oviducal artery. It is important to notice that anteriorly the three longitudinal arteries, which have just been referred to, spring from separate branches of the superior mesenteric*. What should be, so to speak, the ovarian artery is, as usual, the first artery after the superior mesenteric to spring from the aorta. The arrangement of the arteries and veins in this region of the body is illustrated in the accompanying drawing (text-fig. 68, p. 348). The ovarian artery, as w e must call it, runs straight towards the middle of the suprarenal body. Arrived at the edge of that body it divides into two branches, of which the anterior forms the longitudinal vessel of the ovary and almost immediately gives off a stout branch to the fat-body. The posterior branch supplies the oviduct, to which it gives off four branches, of which, as has been already mentioned, the first is the stoutest. The next visceral artery to arise from the aorta is the oviducal artery-of course, of the anterior oviduct. It passes slightly backwards after its origin and then runs forward to near the last of the oviducal branches of the ovarian artery; it then gives off a minute branch which is continuous with the longitudinal system of the ovary and bends sharply back pursuing a posterior course. Immediately after bending it gives off an artery to the fat-body, at least another arteriole to the ovarian longitudinal artery, and divides into two equally sized oviducal branches. Nearer to its point of origin from the aorta, the oviducal artery gives off two branches to the more posterior region of the oviduct. The first of these gives off an artery to the fat-body before dividing into two branches ; the second does not give off such an artery. After the oviducal artery the aorta gives off two vessels situated exactly opposite to each other. The right-hand one of these runs parallel with the oviducal artery and actually emits one or two arterioles which convey blood to the oviduct. The main trunk, however, supplies the fat-body. There are other trunks supplying the anterior oviduct which will be dealt with in the order of their origin from the aorta f. The next trunk to be considered is the second ovarian artery. This artery in many ways repeats the conditions observable in the anterior ovarian artery. It arises from the aorta exactly opposite to the fat-body artery just described, than which it is of course much stouter. Arrived at the edge of the suprarenal body it divides into an anterior and posterior trunk ; the former is the longitudinally running ovarian artery which gives off numerous small branches to the ovary itself, as well as a number of large trunks to the oviduct. The posterior branch repeats almost exactly the conditions observable in the oviduct of the anterior ovary. It gives off one branch immediately, which is soon followed by three others ; there are thus four in all, as with the anterior oviduct. The main difference is that none of these * See the description of that artery, p. 347. f In connection with the renal arteries : see p. 350. |
