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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