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
(pp. 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.
C. _Female Urogenital Organs_ (p. 263, and Fig. 112). The kidney and its
ducts and the bladder are like those of the male (p. 255), except the
neck of the bladder, which will be seen in dissecting the uterus and
vagina.
_a._ Without cutting anything examine--
1. The ovaries (p. 264); the ligaments of the ovary (p. 264, and Fig.
112).