Male Reproductive System

Male Reproductive System

Testes and Epididymis

• Location: Scrotum
• Structure: Paired reproductive glands that produce sperm and male hormones
• Covered by: Tunica Vaginalis (visceral layer) and Tunica Albuginea (tough fibrous outer surface)

Vas Deferens, Seminal Vesicles, and Ejaculatory Ducts

• Vas Deferens:
  • Continuation of the Epididymis
  • Thick muscular wall and small lumen
  • Begins at the inferior pole of the testes and ascends posterior to the testis medial to the epididymis
  • Primary component of the spermatic cord
  • Penetrates the anterior abdominal wall via inguinal canal
• Seminal Vesicles:
  • Elongated structure that lies between the fundus of the bladder and the rectum
  • Place obliquely superior to the prostate
  • Do not store sperm
  • Secretion: thick alkaline fluid, fructose, and coagulating agent
• Ejaculatory Ducts:
  • Formed by the union of the seminal glands and ductus deferens
  • Formed near the neck of the bladder
  • Run through the posterior part of the prostate and along either side of the prostatic utricle
  • Converge to open on the seminal colliculus by tiny apertures

Prostate Gland

• Location: Largest accessory gland in the male reproductive system
• Structure: Surrounds the prostatic urethra
• Composition: Two-thirds glandular and one-third fibromuscular
• Relationships:
  • Base: closely related to the base of the bladder
  • Apex: in contact with fascia on the superior aspect of the urethral sphincter and deep perineal muscles
  • Anterior surface: muscular, separated from the pubic symphysis by retroperitoneal fat in the retropubic space
  • Posterior surface: related to the ampulla of the rectum
  • Inferolateral surface: related to levator ani muscle

Prostate Gland: Lobes

• Isthmus: lies anterior to the urethra, fibromuscular, and represents a superior continuation of the external urethral sphincter muscle to the neck of the bladder
• Right and left lobes: separated posteriorly by a central shallow longitudinal furrow, and separated anteriorly by the isthmus

Prostate Gland: Zones

• Not explicitly mentioned in the text

Prostate Gland: Blood Supply, Nerve Innervation, and Lymphatic Drainage

• Arterial supply: branches of the internal iliac artery, inferior vesical arteries, internal pudendal arteries, and middle rectal arteries
• Venous drainage: veins join the prostatic venous plexus, which drains into the internal iliac veins
• Lymphatic drainage: drains into the internal iliac nodes and sacral lymph nodes

Bulbo-Urethral Glands

• Location: posterolateral to the intermediate part of the urethra, largely embedded within the external urethral sphincter
• Structure: two pea-sized glands
• Function: mucous-like secretion
• Ducts: pass through the perineal membrane with the intermediate urethra and open through many apertures in the proximal part of the spongy urethra in the bulb of the penis

Scrotum

• Structure: cutaneous sac consisting of two layers: pigmented skin and dartos fascia
• Divided internally by the septum of the scrotum, which is a continuation of the dartos fascia
• Scrotal raphe: a cutaneous ridge marking the line of fusion of the embryonic labioscrotal swellings

Scrotum: Blood Supply, Nerve Innervation, and Lymphatic Drainage

• Arterial supply: posterior scrotal branches of the perineal artery, anterior scrotal branches of the deep external pudendal artery, and cremasteric artery
• Venous drainage: accompanies the arteries
• Lymphatic drainage: drains into the superficial inguinal lymph nodes

Penis

• Structure: consists of thin skin, connective tissue, blood vessels, lymphatics, fascia, corpora, and the spongy urethra
• Parts: root, body, and glans
• Ligaments: suspensory ligament and fundiform ligament

Penis: Internal Structure

• Composed of three cylindrical cavernous bodies: paired corpora cavernosa and corpus spongiosum
• Cavernous bodies: each covered with fibrous capsule called the tunica albuginea, and covered with deep fascia of the penis (Buck fascia)

Penis: Blood Supply, Nerve Innervation, and Lymphatic Drainage

• Arterial supply: dorsal arteries of the penis, deep arteries of the penis, and arteries of the bulb of the penis
• Venous drainage: deep dorsal vein of the penis, which joins the prostatic venous plexus
• Lymphatic drainage: drains into the superficial external pudendal vein

Mechanism of Erection and Ejaculation

• Erection: occurs when the corpora cavernosa and corpus spongiosum become engorged with blood at the arterial pressure, causing the erectile bodies to become turgid and elevate the penis
• Ejaculation: results from the closure of the internal urethral sphincter at the neck of the urinary bladder, contraction of the urethral muscles, and contraction of the bulbospongiosus muscles