Vas (ductus) deferens, spermatic cord, seminal vesicles
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:
- External Spermatic Fascia: From the aponeurosis of the external oblique muscle.
- Cremaster Muscle and Fascia: From the internal oblique muscle and its fascia; the cremaster muscle regulates the temperature of the testes.
- 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.