9.3 Male Reproductive Organs

• Male Reproductive Organs Overview

  • Gonads: Testis

    • Function: Produces sperm and secretes male sex hormones.

  • Ducts:

  • Epididymis: Stores sperm.

  • Ductus (Vas) Deferens: Transports sperm from epididymis to ejaculatory duct.

  • Ejaculatory Duct: Connects to the urethra.

  • Urethra: Conducts urine and semen out of the body.

  • Exocrine Glands:

  • Seminal Vesicles: Produce 60% of semen, containing fructose and fibrinogen.

  • Prostate Gland: Produces 30% of semen, responsible for fluid secretion.

  • Bulbourethral Glands: Produce alkaline mucus to lubricate and neutralize urethra.

• Anatomy Layout:

  • The male reproductive organs are located within the scrotum, which contains the testes and associated structures.

  • Important anatomical structures include:

  • Scrotum

  • Epididymis

  • Ductus Deferens

  • Seminal Gland (seminal vesicles)

  • Ejaculatory Duct

  • Prostate

  • Bulbourethral Glands

  • Urethra

  • Penis

• Scrotum
  • contains testis
  • scrotal raphe
  • divided by septum
  • cremaster muscle; dartos muscle
  • scrotal coverings

• Pines

  erectile tissue:
  • paired corpora
  cavernosa
  • corpus
  spongiosum

• Ductus Deferens:

  • Extends from the epididymis to the ejaculatory duct.

  • Located primarily in the spermatic cord; travels through the inguinal canal.

• Blood Supply to Testis:

  • Vascular supply includes:

  • Testicular Artery: Supplies blood to the testis.

  • Pampiniform Plexus: Venous drainage from testis.

  • Cremasteric Artery: Supply to the cremaster muscle.

• Lymphatic Drainage:

  • Primary nodes involved in lymph drainage:

  • Internal iliac nodes

  • External iliac nodes

  • Lumbar nodes

• Nerve Innervation:

  • Sympathetic Nervous System:

  • Innervates the testis and associated glands.

  • Parasympathetic Nervous System:

  • Involved in erection and blood flow regulation.

Testes: Sympathetic nerves
Epididymides: Sympathetic nerves from the coeliac ganglion
Ductus deferens and seminal vesicle: Pelvic plexus
Prostate: Pelvic splanchnic nerves
Penis: Pudendal nerves, Perineal nerves, Posterior scrotal and dorsal nerves
Pelvic splanchnic nerves ( S2 and S3nerves)
Scrotum: Ilioinguinal nerve (L1) Scrotal branches of the perineal nerve

• Functionality of Muscles:

  • Cremaster Muscle: Regulates testicular temperature by raising or lowering the testes.

  • Dartos Muscle: Lowers heat loss by reducing the surface area of the scrotum.

• Prostate Gland:

  • Location: Under the bladder, anterior to the rectum.

  • Age-related hypertrophy can affect urinary flow, as urine passes through the prostatic urethra.

• Ejaculation Process:

  • Sperm produced in testes →

  • Mature in epididymis

  • Transported via vas deferens →

  • Mixed with seminal fluid from seminal vesicles →

  • Pass through ejaculatory duct in prostate →

  • Exit through urethra

  • Vasectomy: Cutting the vas deferens to prevent sperm exit, leading to sterility.

• Key Takeaways:

  • Understanding the anatomy and physiology of male reproductive organs is essential for recognizing reproductive health issues.

  • The interconnectedness of structures is crucial for sperm production, transportation, and ejaculation.