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Testis, Epididymis, and Spermatic Cord: Gross Anatomy
- Anatomy of the Testes: Gross appearance, vascular supply, innvervation, spermatic cord.
- Anatomy of the Testes: Histology, Spermatogenesis.
- Anatomy of the Testes: Male Hormones (Testosteron, LH, FSH, Inhibin).
References: (Benninghoff, 1993).
Gross Anatomy of the Testis
The testes are paired organs in the scrotum, 4 × 3 × 2.5 cm, 20–25 ml volume. The testicles have a strong organ capsule (tunica albuginea testis). The testicular parenchyma is composed of 250–350 lobules, which drain through the mediastinum testis to the epididymis. The lobules are separated by connective tissue septa (Septula testis) originating from the mediastinum testis. A lobule of the testis consists of one or several seminiferous tubules, which end and start at the rete testis.
Anatomy of the Epididymis
The epididymis is 5–10 mm thick and extends from the upper to the caudal pole of the testis. The epididymis can be divided into caput, corpus, and cauda. A thin capsule and the serosa of the tunica vaginalis cover the epididymis.
8–10 efferent ducts transport the sperm from the rete testis into the epididymal duct (ductus epididymidis). The epididymis consists mostly of the coiled epididymal duct, which passes into the ductus deferens at the cauda of the epididymis [fig. cross section of the testis and epididymis].
Anatomy of the Scrotum
The following structures enclose the contents of the scrotum, from outside to inside: scrotal skin, tunica dartos, the tunica vaginalis testis lamina parietalis provides the serous cavity for the testis (cavum serosum testis). The tunica vaginalis testis lamina visceralis is the serous covering of the testicle. The strong tunica albuginea surrounds the testicular tissue.
Residual structures of testicular development:
The appendix testis (hydatid of Morgagni) and appendix epididymis are remnants of testicular embryology (Müllerian duct), also called testicular appendages.
Spermatic Cord and Vascular Supply of the Testis
The vas deferens (ductus deferens) connects the epididymis with the urethra. Shortly before the prostate, the vas deferens enlarges to the Ampulla ductus deferens. The union of the vas deferens and the duct of the seminal vesicle forms the ejaculatory duct. The ejaculatory ducts pass through the prostate and empty at the Colliculus seminalis in the urethra.
The following structures accompany the ductus deferens from the abdomen to the testis in the spermatic cord [Fig. male external genitals]:
Ductus deferens (vas deferens):
The ductus deferens connects the epididymis to the urethra.
Arteries of the spermatic cord:
Testicular artery (from the aorta), deferential artery (from the internal iliac artery), and cremasteric artery (from the inferior epigastric artery).
Veins of the spermatic cord:
The pampiniform plexus (venous plexus in the spermatic cord) forms the testicular vein and empties into the renal vein (left side) or vena cava (right side).
The lymphatic vessels of the testis drain via the spermatic cord to the paraaortic lymph nodes. Testicular tumors metastasize first to this lymph node station. The lymphatic vessels of the scrotum drain to the inguinal lymph nodes.
Nerves of the spermatic cord:
Sympathetic nerves originate from paraaortic ganglia (T10--L1) and the parasympathetic nerves originate from S2--4. Afferent innervation mediates pain, efferent innervation controls the vessels and to some (unknown) extend the testicular and epididymal functions.
Ramus genitalis from the genitofemoral nerve: originates from the lumbar plexus (L1–2) and passes through the inguinal canal. It supplies the scrotal skin, cremasteric muscle and tunica dartos.
Ilioinguinal nerve: originates from the lumbar plexus (L1) and supplies the scrotal skin, penis, groin, and medial thigh.
The hull of the spermatic cord:
Following structures enclose the contents of the spermatic cord, from outside to inside: scrotal skin, tunica dartos, external spermatic fascia, cremasteric muscle, and internal spermatic fascia.
|Erection of the Penis||Index||Testis Histology|
Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
ReferencesBenninghoff 1993 BENNINGHOFF, A.: Makroskopische Anatomie, Embryologie und Histologie des Menschen.
München; Wien; Baltimore : Urban und Schwarzenberg, 1993
Deutsche Version: Anatomie der Hoden.