Anatomy of the Cat

by Jacob Reighard; H. S. Jennings

2. Carefully remove the integument about the anus and expose the external sphincter ani muscle ([p. 268], and [Fig. 113], i). Trace it to its origin. Remove the integument of the scrotum and dissect the intercolumnar fascia, the levator scroti muscle ([p. 271], and [Fig. 113], j), the tunica vaginalis communis, and propria ([p. 258]).

3. The testis; the epididymis with great care, especially in uncovering the vasa efferentia; the vas deferens and spermatic cord ([p. 259], and [Figs. 110] and [111]).

4. Follow the cord to the external inguinal ring ([p. 259]) and expose the ring. Dissect off in order from the inguinal canal: (a) The external oblique muscle; (b) the internal oblique muscle; (c) the transversus. In this way the cord is followed with its tunica communis and tunica propria to the internal inguinal ring.

5. Trace the vas deferens ([p. 260], and [Fig. 111]) within the abdominal cavity as far as it can be seen dorsad of the neck of the bladder.

6. The penis ([p. 262], and [Figs. 111] and [113]). Cut the skin along the dorsum of the penis and reflect. Dissect the ligamentum suspensorium penis. Then introduce a bristle into the urethra and remove the integument from the whole penis and identify the corpora cavernosa and corpus spongiosum and the urethra.

7. Remove the fat at the side of the rectum and find the levator ani muscle ([p. 269], and [Fig. 162], 11). Transect and reflect it. The internal sphincter ani ([p. 269], and [Fig. 113], h). Find the external opening of the anal gland ([p. 239]); slit and examine it.

8. Dissect the ischiocavernosus ([p. 269]) and bulbocavernosus ([p. 271]) muscles ([Fig. 113]), and find the bulbus of the corpus cavernosum beneath the former. Cut it free from the ischial ramus.

9. Clean the muscles from the pelvis on the side from which the crus penis is removed, and remove with bone forceps the body of the pubis and the ramus of the ischium. Then trace the neck of the bladder to its junction with the vasa deferentia, and the urethra from that point to the external opening ([Fig. 111]). Study the compressor urethræ muscle ([p. 271], and [Fig. 113], n). Find Cowper’s glands ([p. 261]) and the prostate gland ([Fig. 113]). Dissect the other muscles of the urogenital organs (p[p. 268] to 273, and [Fig. 113]).

10. Slit the urethra on one side throughout its length and find the veru montanum ([p. 261]); the openings of the vasa deferentia ([p. 261]), by bristles passed into the urethra from them; the openings of the prostate gland and the openings of Cowper’s glands.

11. Study the structure of the penis ([p. 262]) by making a cross-section, and that of the glans by making a longitudinal section. Note, if possible, the os penis.