the posterior border of the testis. Each border ends above in the tremity, and below in the inferior extremity of the testis. Owing to an the long axis of the gland, the superior extremity of the testis lies on erior and lateral plane than the inferior extremity. ymis.—The epididymis is a somewhat crescentic structure, which is curved posterior border of the testis and overlaps to some extent the posterior lateral surface of that organ. The superior, somewhat swollen part of 'mis, is called the caput epididymidis or head, and overhangs the superior testis, to which it is directly connected by numerous emerging ducts, by tissue, and by the serous covering of the organ. The inferior and smaller led the cauda epididymidis or tail, and is attached by loose areolar tissue serous covering to the inferior end of the testis. The intermediate part, or corpus epididymidis, is applied against, but is separated from, the art of the lateral surface of the testis by an involution of the serous f the organ, which forms an intervening pocket termed the sinus epiO.T. digital fossa). in mass of the epididymis is composed of an irregularly twisted canal, epididymidis, which forms the first part of the duct of the testis. sessile, or pedunculated, bodies are often found attached to the head of the or to the superior end of the testis. These are called appendices of the and testis (0.T. hydatids of Morgagni), and have a developmental interest. : body which lies on the superior end of the testis represents the free end of ct in the embryo and the fimbriated end of the uterine tube of the female ; it essile. Above the head of the epididymis, and in front of the lower part of tic cord, there may also be present a small rudimentary body called the This is rarely seen in the adult, and is best marked in young children. Vaginalis.—The cavity within which the testis and epididymis are lined by a smooth serous membrane — the tunica vaginalis — which in appearance and structure neum, from which it is origind. The cavity is considerably Lobules of - Spermatic cord an the contained structures, epididymis ads not only down to a lower the testis, but also reaches to a higher level than the Efferent he sac, or cavity, tapers as dnctules Appendix ed upwards, and above the Body of testis epididymis he testis the funiculus speror spermatic cord bulges Sinus of epididymis into its posterior part. The ginalis lines the cavity for s, and is reflected from the wall of the scrotal chamber testis and epididymis, giving ng to each. The part of the e lining the cavity is called a parietalis or parietal portion nica vaginalis, while the part the testis and epididymis is ne lamina visceralis or visceral FIG. 1004.- LEFT TESTIS AND EPIDIDYMIS. Between the lateral surface A part of the tunica vaginalis has been removed in order to show the ductuli efferentes and lobuli epididymidis. Cestis and the body of the is, the visceral part of the tunica vaginalis dips in and lines a narrow called the sinus epididymidis (O.T. digital fossa). The entrance to the sinus 1 above and below by short crescentic folds of the tunica vaginalis, which 2 the testis to the head and tail of the epididymis. These folds are spoken superior and inferior ligaments of the epididymis . In three positions the of the testis receives no covering from the tunica vaginalis-superiorly proaches Eb where the globus major is attached, inferiorly where the cauda epididymidis is in contact, and posteriorly where the blood-vessels and nerves enter the organ from ecididymis tb the funiculus spermaticus or spermatic cord. tich constitu Structure of the Testis and Epididymis.—Beneath the serous tunica vaginalis candymis. the testis is invested by an external coat, composed of dense white inelastic fibrous s to begin tissue called the tunica albuginea, from the deep surface of which a number of slender fibrous bands or septa dip into the gland. These—the septula testis-im In most perfectly divide the organ into a number of wedge-shaped parts called lobuli testis thuis ma (Fig. 1005). All the septa end posteriorly in å mass of fibrous tissue which is i one of Tunica albuginea directly continuous with the tunica alSeptula testis buginea, and which projects forwards into Minuto < the testis along its posterior border. This med by a cil structure receives the name of mediastinum ze ductus aei testis, or corpus Highmori, and is traversed under stra by an exceedingly complicated network of ter strat D fine canals, into which the minute tubules bra The which compose the substance proper of the such thick ez testis open. The mediastinum is also pierced by the arteries, veins, and lymph vessels of the testis. These vessels enter the posterior Vessels as Sesuppe zes border of the organ, and traversing the manch of the mediastinum, spread out on the fibrous septa which radiate towards all parts of the deep surface of the tunica albuginea. In this way Ductus deferens Body of epididymis a delicate network of vessels (tunica vasculosa) is formed on the deep surface of the tunica albuginea and on the sides of the septa. The mediastinum, the septa, and the tunica albuginea form a framework enclosing a number of imperfectly isolated spaces which are filled by a loosely packed substance of a light brown colour called the parenchyma testis. The parenchyma is composed of enormous numbers of much-convoluted seminiferous tubules, called tubuli seminiferi contorti, and completely fills up the intervals between the septa. The minute tubules look like fine threads to the unaided eye, and are but loosely held together by a small amount of connective tissue. Usually three or four tubules are found in each lobule of the gland, and the total number Z in the testis has been estimated at about 600. The seminiferous tubules, after a course of about two feet in length, pass towards the mediastinum testis and unite at acute angles, to form a smaller number of slender tubes which run a straight course. These latter are called tubuli seminiferi recti, and open into a complicated network of fine canals situated in the substance of the mediastinum, called the rete testis. The tubules are much more twisted and convoluted in the cortical part of the gland, near the tunica vaginalis, than in the region of the mediastinum, and often give off side branches which, according to some observers, may effect anastomoses between the tubules. It appears doubtful, however, if the semini The neres ferous tubules of the testis do really anastomose. Microscopic sections show that the walls of the seminiferous tubules are composed of a basement membrane and of an epithelial lining, formed of several layers of cells. e testis commu Certain cells of this epithelium are, in the adult, constantly undergoing transformation into spermatozoa, and the appearance of the tubules in section varies much, according to age and to the greater or less activity of the epithelial cells. The secretion of the seminiferous tubules is carried through the tubuli seminiferi recti into the rete testis, and leaves the latter, to reach the canal of the epididymis, through from fifteen to twenty minute tubules called ductuli efferentes testis or efferent ductules. These latter pierce the tunica albuginea and enter the caput epididymidis where it is in direct contact with the superior extremity of the testis. Each efferent ductule is at first straight, but soon becomes much convoluted, and forms a little conical mass of twisted tubule, called img cours Papiniforms aortic a Serent fibres 3 of the due The lymphar lymph-g The ductus of the epididy after a course prostatic or fir evoluted, an Placed in the the epididymis (O.T. conus vasculosus). Within the head of the the little canals finally open into the single much-convoluted tube tutes the chief bulk of the epididymis, and is called the duct of the This canal, which is not less than 19 or 20 feet in length, may be in in the head of the epididymis, and to end, after an extraordinarily irse, at the tail by becoming the ductus deferens (Fig. 1006). cases one or more slender convoluted diverticula from the duct of the epibe found near its lower end. These receive the name of ductuli aberrantes, them which is very constantly present often measures a foot or more in Structure. The duct of the epididymis and the efferent ductules are ciliated epithelium, the cilia of which maintain a constant current towards deferens. The duct of the epididymis possesses a muscular coat composed of tratum of transversely and an um of longitudinally directed e wall, at first thin, becomes ker as the ductus epididymidis speriaticus Ductus ---deferens the ductus deferens. Head of epididymis and Nerves of the Testis.- The plied by the internal spermaticartery, the aorta. This slender vessel, after uctus erens Appendix of testis Head of epididymis Cut edge of tunicavaginalis Duct of epididymis of dymis FIG, 1006. and epididymis. FIG. 1007.-LEFT TESTIS AND EPIDIDYMIS VIEWED FROM BEHIND, showing the ductus epididymidis and the first part of the ductus deferens. course, reaches the posterior border of the testis, where it breaks up into branches enter the mediastinum testis, and are distributed along the septa and on the deep surface tunica albuginea. e veins issuing from the posterior border of the testis form a dense plexus, called the plexus niformis, which finally pours its blood through the spermatic vein, on the right side, into the or vena cava ; on the left side the spermatic vein joins the left renal vein. e nerves for the testis accompany the internal spermatic artery, and are derived through ortic and renal plexuses from the tenth thoracic segment of the spinal medulla. The at fibres from the epididymis appear to reach the spinal medulla through the posterior of the eleventh and twelfth thoracic and first lumbar nerves. The arteries and nerves of estis communicate with those on the lower part of the ductus deferens, namely, with the y of the ductus deferens and with twigs from the hypogastric plexus. The lymph-vessels of the testis pass upwards in the spermatic funiculus, and end in the par lymph-glands. DUCTUS DEFERENS. The ductus deferens (0.T. vas deferens) is the direct continuation of the duct he epididymis. Beginning at the inferior extremity of the epididymis, it ends, er a course of nearly 18 inches, by opening as the ejaculatory duct into the static or first part of the urethra. "The duct in parts of its course is somewhat voluted, and the actual distance traversed by it is not more than 12 inches. aced in the first instance outside the abdominal cavity, the ductus deferens ascends superior iliac structures of within the scrotum towards the lower part of the anterior abdominal wall, which it to the abdom structure so formed is termed the funiculus spermaticus or spermatic cord. The ductus deferens, together with the accompanying vessels and nerves, now passes of the ingus through the abdominal wall in an oblique passage, to which the name canalis etique al inguinalis is applied. Within the abdomen the duct lies immediately beneath the ackward peritoneum, and soon crossing over the pelvic brim, it enters the pelvis minor, on cued ten da the side wall of which it proceeds backwards towards the base of the bladder. Here, zierally u P near the median plane, the ductus deferens is joined by the duct of the correspond- the inter Median umbilical ligament (urachus) Urinary bladder se inguina Plica vesicalis transversa Paravesical peritoneal fossa Trigonum femorale Obliterated umbilical artery External Inferior iliac vessels epigastric artery Internal spermatic artery Ureter External iliac artery Hypogastric artery Rectum Sacro-genital fold of the ductus deferens is well seen. The oils of 3 zastric its ing vesicula seminalis, and the ejaculatory duct, thus formed, having traversed the prostate, opens into the urethra. At first the ductus deferens, like the canal from which it takes its origin, is very tortuous, but soon increasing in thickness, the duct becomes less twisted, and passes upwards along the medial side of the epididymis, behind the testis, to enter the spermatic funiculus (Fig. 1007). Its course is now almost vertically upwards towards the pubic tubercle, near which, crossing the medial part of the inguinal ligament [Pouparti], the duct enters the inguinal canal by the subcutaneous inguinal ring (Fig. 1017). Of the structures composing the funiculus spermaticus the duct is the most posterior, and it can be readily distinguished, even in the undissected subject, by its hard firm feel, when it is taken between the finger and thumb.In the inguinal canal the ductus deferens is directed laterally, upwards, and a little backwards to the abdominal inguinal ring, where, at a point half an inch above the inguinal ligament, and midway between the symphysis pubis and the anterior direction of ni upwards, be pubic tuber In this part of pensels, and th between these elvis minor th Etially, in th peritoneum, the ita course the nk the umbilic and (4) the ur or iliac spine, it enters the abdomen. The distance between the point where rd enters the inguinal canal to the point where it leaves it to enter the en is about one and a half inches. While passing from the subcutaneous abdominal inguinal ring the ductus deferens, together with the other cres of the funiculus spermaticus, rests upon the upper grooved surface inguinal ligament, and is placed behind the aponeurosis of the external and some of the lower fibres of the internal oblique muscle. From before -rds the duct rests, in the first instance, upon the falx aponeurotica or conendon of the internal oblique and transversus abdominis muscles, and farther y upon the fascia transversalis. Above the funiculus are some arching fibres nternal oblique muscle which enter the falx. As the ductus deferens leaves uinal canal by the abdominal inguinal ring, it turns round the inferior Branches of hypogastric artery Right ureter Nerve cord from hypogastric plexus ferior istric rtery Eacro-genital fold Vesical arteries Ductus deferens Paravesical peritoneal fossa Fig. 1009.-MEDIAN SECTION OF THE PELVIS IN AN ADULT MALE. small intestine and colon which lay within the pelvis have been lifted out in order to give a view of the side wall of the pelvic cavity. artery on its lateral and posterior aspect. Completely changing the of its course, the duct now runs for a short distance backwards, medially, ards, beneath the peritoneum, to a point one and a half to two inches from tubercle, where it crosses the ilio-pectineal line and enters the pelvis minor. art of its course the duct usually lies at first in front of the external iliac nd then in the floor of a little triangular fossa, the trigonum femorale, these vessels and the pelvic brim (Fig. 1009). On the side wall of the aor the ductus deferens is continued backwards, and a little downwards and in the direction of the ischial spine, and lies immediately external to the m, through which it can usually be seen shining. In the pelvic part of the ductus deferens crosses on the medial side of (1) the obliterated part mbilical artery, (2) the obturator nerve and vessels, (3) the vesical vessels, he ureter (Fig. 1009). |
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