Seminal vesicles. Prostate. Bulbo-urethral gland

• Seminal vesicles

  • Pair folded tubular glands that are responsible for producing significant portion of male seminal fluid that combines with sperm to form semes
• Seminal vesicles- relations:

  • Located in pelvis
  • Anterior: prostate and bladder
  • posterior: rectum
  • Medial margins: ampulla of vans deferens
  • Laterally: veins of prostate venous plexus
  • Superior: distal ureter

  
• Structure of seminal vesicle

  • Each seminal vesicle is coiled, tubular gland that when uncoiled measures about 10-15cm in length.
  • Seminal vesicles are enclosed by fibrous capsule and have highly folded mucosal lining, which increases surface area for secretion. A short excretory duct from seminal vesicle combines with ampulla of ductus deferens to form ejaculatory duct

  
• Functions of seminal vesicles

  1. secretion of seminal fluid: produces about 60-70% volume if seminal fluid
  2. Ph regulation: seminal fluid is slightly alkaline which hells neutralize ph of vagina
• Excretory ducts: each seminal vesicles has excretory ducts that joins vans deferens to form ejaculatory duct. Each ejaculatory duct pass through prostate gland and open into protatic uretha

  
• Blood supply of seminal vesicles

  • arterial: inferior vesical and middle rectal artery. ( both are branches of internal iliac)
  • venous: drains into prostatic and vesical venous plexus.
  • Lymphatics: drains into iliac lymph nodes
• Prostate gland


  Collec if tubuloacinar glands embedded in a dense fibromuscukar stroma in which smooth muscle contracts at ejaculation

  • large accessory gland of male reproductive system.
  • Plays role in production of seminal fluid, which nourishes and transports sperm.
• Prostate gland is located in pelvis, inferior to urinary bladder and superior to urogenital diagram . It surrounds prostatic urethra, a portion of urethra that passes through prostate

  
• Anatomical zones of prostate gland

  Prostate gland is subdivided into: 4regions

  1. Peripheral zone: larges, making up about 70% of prostate volume. Located posteriorly, surrounds distal urethra and is the common site for prostate cancer
  2. Central zone: 25% of glands volume. Surrounds ejaculatory ducts as they converge to enter urethra.
  3. Transitional zone: 5% but can expands with age. Located surround proximal urethra
  4. Anterior fibromuscular stroma: dense fibrous tissue and smooth muscle. Does not contain glanddular tissue.

  
• Blood, venous supply and lymphatics of prostate gland

  • Inferior vesicle artery: branch of internal iliac
  • venous: prostatic venous plexus which drain into internal iliac veins
  • lymph: drains into internal + external iliac + sacral lymph nodes.

  Sympathetic: fiber from hypogastric plexus: responsible for contraction of smooth muscle during ejaculation

  Parasympathetic: fiber from splanchnic nerved contribute to regulation of glandular secretion
• Relations of prostate gland

  • Sup: urinary bladder
  • inf: urogenital diagram + pelvic floor
  • Ant: positioned behind pubic symphysis separated by a layer of fat in retropubic space
  • Post: rectum is located behind prostate, and is separated from it by rectovesical septum. This allows prostate to be palpable during digital rectal examination
  • lat: levator ani, pelvic sidewalls

  
• Function of prostate gland

  • Secretio: produces milky fluid that constitutes 39% of semen volume. This fluid contains prostate-specific enzyme + other substances
  • Ejaculation: during ejaculation muscles of the prostate contracts to expel prostatic fluid into urethra where it mix with Seminal vesicle fluid to form semen