45. In the first place, the structure of the spine known, for this knowledge is requisite in many diseases. Wherefore, on the side turned to the belly (the anterior?) the vertebrae are in a regular line, and are united together by a pulpy and nervous band of connection, originating from the cartilages, and extending to the spinal marrow.
There are certain other nervous cords which decussate, are attached (to the vertebrae?), and are extended from both sides of them. But we will describe in another work the connections of the veins and arteries, their numbers, their qualities, their origin, their functional offices in particular parts, in what sort of sheaths the spinal marrow is inclosed, where they arise, where they terminate, how they communicate, and what their uses. On the opposite side (behind?) the vertebrae are connected together by a ginglymoid articulation. Common cords (nerves?) are extended to all parts, both those within and without. There is an osseous process from the posterior part of all and each of the vertebra, whether greater or smaller; and upon these processes there are cartilaginous epiphyses, and from them arise nervous productions (ligaments?), akin to the external nerves (tonoi). The ribs are united to them, having their heads inclined rather to the inside than the out, and every one of them is articulated with the vertebrae; and the ribs in man are very curved, and, as it were, arched. The space between the ribs and the processes of the vertebrae is filled on both sides by muscles, which arise from the neck and extend to the loins (?). The spine, longitudinally, is a straight line slightly curved; from the os sacrum to the great vertebra which is connected with the articulation of the femur, the spine inclines backward, for the bladder, the organs of generation, and the loose portion of the rectum, are situated there.
From this, to the attachment of the diaphragm, the spine inclines inward, and this portion alone, from the internal parts, gives origin to muscles, which are called psoae. From this to the great vertebra (seventh cervical?) which is above the tops of the shoulders, it is convex behind lengthways; but it is more in appearance than it really is, for the spinous processes are highest in the middle, and less so above and below. The region of the neck is convex before.
