Prostate Diseases

18 Prostate Diseases

Basic Anatomy

image

Pelvic Cavity, Bladder, and Prostate

Prostate Proper

• Largest accessory gland of the male genital tract
• Partly glandular, partly fibromuscular
• Glandular growth and maturation controlled by testosterone, which is converted to dihydrotestosterone (DHT) by 5-alpha reductase
• Peri-urethral transition zone of the parenchyma: <10% of the stroma
• Peripheral zone of the gland: ~70% of the normal gland
• Smooth musculature of the prostate: part of the involuntary sphincter of the bladder
• Normal: walnut sized, ~20 g
• 5 “traditional” lobes
image Anterior (isthmus): largely muscular, sphincteric (see later)
image Middle: lies between urethra and ejaculatory ducts
image Posterior (inferoposterior): posterior to urethra and ejaculatory ducts, palpable (see later)
image Left and right lateral: form the majority of the prostate
• Middle lobe: most common site of benign prostatic hyperplasia (BPH), process arising in the periurethral transitional zone
• Anatomical parts: base, apex, four surfaces
image Base: vesicular surface, related to the base of the bladder
image Apex: inferior point, related to superior fascia of the urogenital diaphragm
image Anterior surface: retropubic, with largely transverse musculature, forms a rhabdosphincter (hemisphincter)
image Posterior surface: triangular, rests on ampulla of the rectum, palpable
image Inferolateral surfaces: resting on levator ani muscles and fascia
• Supported anteriorly by puboprostatic ligaments, central portions of the pubococcygeus, part of the levator ani muscles (anterior pelvic diaphragm)
• Supported inferiorly by the urogenital diaphragm (transversus perinei muscle and fascia), through which the urethra passes
• Bulbourethral (Cowper’s) glands
image Lie inferior and adjacent to the prostatic apex, within the urogenital diaphragm
image Provide mucus secretion for penile urethra

Prostatic Capsule(s)

• Prostatic (true) capsule: thin, dense, fibrous connective tissue enclosing parenchyma and surrounded by—
• False capsule: prostatic sheath, derived from inferior, endopelvic fascia
image Sheath is continuous inferiorly with superior fascia of urogenital diaphragm.
image Posterior sheath is part of the rectovesical septum.
• Prostatic venous plexus lies between prostatic capsule and surrounding sheath.

Prostatic Ducts and Urethra

• Multiple small prostatic ductules penetrate wall of prostatic urethra.
• Seminal colliculus (verumontanum) in posterior urethral wall marks location of paired ejaculatory ducts draining ductus deferens and seminal vesicles.
• Prostatic utriculus: small midline invagination in dome of colliculus, marks remnant of embryonic male paramesonephric (müllerian) ducts (“male uterus”)

Related posts:

  1. Uterus and Adnexal Diseases
  2. Pancreatic Diseases
  3. Pelvic Fractures
  4. Liver Diseases

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Aug 12, 2016 | Posted by in ANATOMY | Comments Off on Prostate Diseases

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