Vas (ductus) deferens, spermatic cord, seminal vesicles
Feedback

From WikiLectures

Spermatic Cord[edit | edit source]

Definition[edit | edit source]

The spermatic cord is a composite structure consisting of vessels, nerves, and ducts that connect the abdominal cavity to the testes, ensuring their vascular, neural, and reproductive functionality.

Anatomical Course[edit | edit source]

  • Formation: The spermatic cord originates at the deep inguinal ring (the entrance to the inguinal canal).
  • Pathway: It traverses the inguinal canal and emerges through the superficial inguinal ring, descending into the scrotum.
  • Termination: It attaches to the posterior border of the testes within the scrotum.

Fascial Coverings[edit | edit source]

The coverings of the spermatic cord are derived from the layers of the abdominal wall during the descent of the testes:

  1. External Spermatic Fascia: From the aponeurosis of the external oblique muscle.
  2. Cremaster Muscle and Fascia: From the internal oblique muscle and its fascia; the cremaster muscle regulates the temperature of the testes.
  3. Internal Spermatic Fascia: From the transversalis fascia.

Contents[edit | edit source]

  • Vessels:
    • Testicular artery: Branch of the abdominal aorta.
    • Artery to the ductus deferens: Branch of the inferior vesical artery.
    • Cremasteric artery and vein: Branches of the inferior epigastric artery.
    • Pampiniform venous plexus: A network of veins enveloping the testicular artery, facilitating thermoregulation by cooling the arterial blood.
  • Nerves:
    • Genital branch of the genitofemoral nerve: Supplies the cremaster muscle.
    • Autonomic nerves: Sympathetic and parasympathetic innervation for vascular control.
  • Other Structures:
    • Ductus deferens: A muscular tube conveying sperm from the epididymis to the ejaculatory duct.
    • Vestige of the processus vaginalis: A remnant of the peritoneal extension formed during testicular descent.

Ductus (Vas) Deferens[edit | edit source]

Description[edit | edit source]

The ductus deferens is a thick-walled, straight muscular tube that transports sperm from the epididymis to the ejaculatory duct, ensuring efficient sperm delivery during ejaculation.

Structure[edit | edit source]

  • Wall Composition:
    • Inner layer: Longitudinal smooth muscle.
    • Middle layer: Circular smooth muscle.
    • Outer layer: Longitudinal smooth muscle.
  • Mucosa: The lumen is lined with pseudostratified columnar epithelium featuring microvilli, which aid in the absorption and secretion processes.
  • Innervation: Autonomic innervation enables rapid contractions to propel sperm during ejaculation.

Seminal Vesicles[edit | edit source]

Anatomical Position[edit | edit source]

  • Paired, elongated glands measuring approximately 5 cm in length.
  • Located posterior to the bladder fundus, separated from the rectum by the rectovesical pouch and rectoprostatic fascia.
  • The ducts of the seminal vesicles join with the ductus deferens to form the ejaculatory ducts, which open into the prostatic urethra.

Structure[edit | edit source]

Internally, the seminal vesicles exhibit a lobulated honeycomb appearance, lined with pseudostratified columnar epithelium, specialized for secretory functions.

Function[edit | edit source]

The seminal vesicles contribute approximately 70% of the semen’s volume. Their secretions include:

  • Alkaline fluid: Neutralizes the acidic environments of the male urethra and female reproductive tract.
  • Fructose: An energy substrate for spermatozoa motility.
  • Prostaglandins: Modulate the female immune response and enhance sperm motility.
  • Clotting factors: Facilitate retention of sperm within the female reproductive system post-ejaculation.

Vasculature[edit | edit source]

  • Arterial Supply: Branches of the inferior vesical artery, internal pudendal artery, and middle rectal artery (all derived from the internal iliac artery).
  • Venous Drainage: Via veins corresponding to the arterial supply, draining into the internal iliac vein.

Innervation[edit | edit source]

  • Sympathetic: From the hypogastric plexus, crucial for secretion during ejaculation.