Читать книгу King's Applied Anatomy of the Abdomen and Pelvis of Domestic Mammals - Geoff Skerritt - Страница 28

Figure 1.11 Ventral view of inguinal canal of the pig. The left side of the diagram shows the superimposition of the superficial inguinal ring almost directly upon the vaginal ring in this species.

Figure 1.12 Lateral view of the inguinal canal of the horse. A window has been cut from the pelvic part of the tendon of the external abdominal oblique muscle immediately adjoining the superficial inguinal ring. This exposes that part of the internal oblique abdominal muscle which forms the medial (deep) wall of the inguinal canal.

The inguinal canal is a potential space extending between the superficial and deep inguinal rings. The canal does not have a surrounding wall. The external opening (superficial inguinal ring) is a slit in the aponeurosis thereby dividing it into two parts, an abdominal part (cranially) and a pelvic part (caudally).

Species variations: The deep inguinal ring is different in the pig from that in the horse due to the different extent to which the internal oblique abdominal muscle inserts caudally. In the horse the deep inguinal ring is small, being bordered caudally by the inguinal ligament and cranially by the caudal edge of the internal oblique muscle (Figure 1.12) In the pig the deep inguinal ring is larger, bordered caudally by the inguinal ligament, cranially by the caudal edge of the internal abdominal oblique muscle and medially by the lateral border of the rectus abdominal muscle and the prepubic tendon (Figure 1.11). In the other domestic animals, the anatomy of the inguinal ring is between the horse and the pig but tends to be closer to the latter.

In the male foetus of all species an outpouching of parietal peritoneum, the vaginal process (Figure 16.6), enters the inguinal canal. The gubernaculum (see Section 16.9) develops from mesenchyme partly within the inguinal canal and joins the testes to the scrotum. In the adult male the inguinal canal contains the vaginal tunic, the cremaster muscle and the spermatic cord in addition to the external pudendal artery and vein, the inguinal lymph vessels and nerves. In the adult female it is only in the bitch that a rudimentary vaginal process extends through the inguinal canal.