Henry Gray (18251861). Anatomy of the Human Body. 1918.
The external spermatic artery is a branch of the inferior epigastric artery. It accompanies the spermatic cord and supplies the coverings of the cord, anastomosing with the internal spermatic artery.
The artery of the ductus deferens, a branch of the superior vesical, is a long, slender vessel, which accompanies the ductus deferens, ramifying upon its coats, and anastomosing with the internal spermatic artery near the testis.
FIG. 1146 The spermatic cord in the inguinal canal. (Poirier and Charpy.) (See enlarged image)
The spermatic veins(Fig. 1147) emerge from the back of the testis, and receive tributaries from the epididymis: they unite and form a convoluted plexus, the plexus pampiniformis, which forms the chief mass of the cord; the vessels composing this plexus are very numerous, and ascend along the cord in front of the ductus deferens; below the subcutaneous inguinal ring they unite to form three or four veins, which pass along the inguinal canal, and, entering the abdomen through the abdominal inguinal ring, coalesce to form two veins. These again unite to form a single vein, which opens on the right side into the inferior vena cava, at an acute angle, and on the left side into the left renal vein, at a right angle.
The lymphatic vessels are described on page 713.
The nerves are the spermatic plexus from the sympathetic, joined by filaments from the pelvic plexus which accompany the artery of the ductus deferens.
The scrotum forms an admirable covering for the protection of the testes. These bodies, lying suspended and loose in the cavity of the scrotum and surrounded by serous membrane, are capable of great mobility, and can therefore easily slip about within the scrotum and thus avoid injuries from blows or squeezes. The skin of the scrotum is very elastic and capable of great distension, and on account of the looseness and amount of subcutaneous tissue, the scrotum becomes greatly enlarged in cases of edema, to which this part is especially liable as a result of its dependent position.
The Testes are suspended in the scrotum by the spermatic cords, the left testis hanging somewhat lower than its fellow. The average dimensions of the testis are from 4 to 5 cm. in length, 2.5 cm. in breadth, and 3 cm. in the antero-posterior diameter; its weight varies from 10.5 to 14 gm. Each testis is of an oval form (Fig. 1148), compressed laterally, and having an oblique position in the scrotum; the upper extremity is directed forward and a little lateralward; the lower, backward and a little medialward; the anterior convex border looks forward and downward, the posterior or straight border, to which the cord is attached, backward and upward.