Male Genital System Anatomy

Male Genital System

• The male genital system is divided into external and internal genitalia.

External Genitalia

• Penis
  • Has a fixed root and a body.
  • Root of the penis is made up of three masses of erectile tissue:
    • Bulb of the penis
    • Right and left crura
    • The bulb is in the midline.
    • Each crus is attached to the side of the pubic arch.
    • The bulb continues forward into the body of the penis.
    • The two crura lie side-by-side in the dorsal part of the body.
  • Body of the penis is composed of three cylinders of erectile tissue:
    • Corpora cavernosa
    • Corpus spongiosum
    • The corpus spongiosum expands to form the glans penis.
• Scrotum
  • An outpouching of the lower part of the anterior abdominal wall.
  • Contains the testes, epididymides, and lower ends of the spermatic cords.
  • The wall of the scrotum has three layers:
    • Skin
    • Superficial fascia
    • Spermatic fascia
    • Tunica vaginalis
• Testis
  • A firm, mobile organ located within the scrotum.
  • Surrounded by a tough fibrous capsule called the tunica albuginea.
  • From the inner surface of the capsule are fibrous septa that divide the organ into lobules.
  • Each lobule contains one to three coiled seminiferous tubules.
• Epididymis
  • A firm structure behind the testis.
  • Has a head, body, and tail (inferiorly).
  • Is a coiled tube (approximately 20 ft or 6 m long).
  • Main function is absorption of fluid.
  • May add substances to seminal fluid to nourish maturing sperm.
• Vas Deferens
  • A thick-walled tube (approximately 18 inches or 45 cm long).
  • Arises from the lower end (tail) of the epididymis.
  • Passes through the inguinal canal.
  • Emerges from the deep inguinal ring.
  • Terminal part called the ampulla of the vas deferens.
  • The inferior end of the ampulla narrows and joins the duct of the seminal vesicle to form the ejaculatory duct.

Internal Genitalia

• Seminal Vesicles
  • Two lobulated organs (approximately 2 inches or 5 cm long).
  • Located on the posterior surface of the bladder.
  • The terminal part of the vas deferens is on the medial side of each vesicle.
  • Posteriorly, related to the rectum.
  • Inferiorly, each narrows and joins the vas deferens of the same side to form the ejaculatory duct.
• Ejaculatory Ducts
  • Less than 1 inch (2.5 cm) long.
  • Formed by the union of the vas deferens and the duct of the seminal vesicle.
  • Pierces the posterior surface of the prostate.
  • Opens into the prostatic part of the urethra.
  • Drains seminal fluid into the prostatic urethra.
• Prostate
  • A fibromuscular glandular organ (approximately 1.25 inches or 3 cm long).
  • Located between the neck of the bladder above and the urogenital diaphragm below.
  • Surrounded by a fibrous capsule.
  • The two ejaculatory ducts pierce the upper part of the posterior surface of the prostate.
  • Produces a thin, milky fluid (containing citric acid and acid phosphatase).
  • Added to the seminal fluid during ejaculation.
  • The prostatic secretion is alkaline and helps to neutralize vaginal acidity.
• Urinary Bladder
  • Located immediately behind the pubic bones.
  • Has a strong muscular wall.
  • The empty bladder is pyramidal, with an apex, a base, and a superior and two inferolateral surfaces.
  • Also has a neck.

Explore the intricate anatomy of the male genital system, focusing on the external genitalia including the penis and scrotum. Understand the structure and composition of the penis, highlighting the erectile tissues and the scrotal anatomy. This quiz will enhance your knowledge of male reproductive anatomy.