URINARY BLADDER

• URINARY BLADDER
  • features
  • muscular reservoir
    • Detrusor muscles
      • arranged in whorls and spirals
  • lies in anterior part of pelvic cavity
  • size
  • variable in size
    • empty state inside pelvic cavity
    • filled state
      • abdominal cavity
  • shape
    • tetrahedral
      • Apex of bladder
      • Body of bladder
      • Base or Fundus of bladder
      • Neck of bladder
    • 3 surfaces
      • superior
      • right
      • left inferolateral
    • 4 borders
      • 2 lateral
      • 1 anterior
      • 1 posterior
    • full bladder
      • ovoid in shape
      • Apex
      • neck
      • 2 surfaces
  • RELATIONS
    • Apex
      • connected to umbilicus
        • median umbilical ligament
          • obliterated embryonic urachus
    • base
      • Female
        • related to uterine cervix and vagina
      • Male
        • upper part
          • Separated from rectum by
            • rectovesical pouch
    • Neck
      • males
      • females
    • superior surface
      • males
        • covered by peritoneum
        • contact with sigmoid colon
        • coils of terminal ileum
      • females
        • Greater part covered by peritoneum
        • peritoneum from superior surface reflected
          • to isthmus of uterus
          • to form vesicouterine pouch
    • inferolateral surface
      • males
        • related to pubis , puboprostatic ligament
        • retropubic fat , levator Ani
        • obturator internus
      • females
        • pubovesical ligaments instead of puboprostatic
  • ligaments of bladder
    • true ligaments
      • lateral true ligament
      • lateral puboprostatic ligament
      • medial puboprostatic ligament
        • females pubovesical ligament
      • median umbilical ligament
      • posterior ligament of bladder
    • false ligaments
      • median umbilical fold
      • medial umbilical fold
      • lateral false ligament
      • posterior false ligament
  • INTERIOR OR BLADDER
    • small triangular area in lower part of base of bladder
      • smooth
        • Trigone of bladder
          • Apex directed downward and forward
          • base of trigone
            • Interureteric crest / ridge ( bar of Mercier )
              • due to continuation of inner longitudinal muscle coat of
                • two ureters
          • Ureteric orifice
          • Internal urethral orifice
          • a slight elevation on trigone due to prostrate
            • Uvula of bladder or vuvula vesicae
  • Serosa; serous coat
  • Subserosa; subserous layer
  • Muscular layer; muscular coat
    • Trigonal muscles
      • Superficial trigone
      • Deep trigone
    • Detrusor
      • Unstratified part
      • Bladder neck part
      • External longitudinal layer
      • Circular layer
      • Internal longitudinal layer
    • Pubovesicalis
    • Rectovesicalis
    • Vesicoprostaticus
    • Vesicovaginalis
  • Submucosa
  • Mucosa; mucous membrane
  • CAPACITY OF BLADDER
    • 120 - 320 ml

When viewed under a microscope the bladder can be seen to have an inner lining (called epithelium), three layers of muscle fibres, and an outer adventitia.

The inner wall of the bladder is called urothelium, a type of transitional epithelium formed by three to six layers of cells; the cells may become more cuboidal or flatter depending on whether the bladder is empty or full. Additionally, these are lined with a mucous membrane consisting of a surface glycocalyx that protects the cells beneath it from urine. The epithelium lies on a thin basement membrane, and a lamina propria. The mucosal lining also offers a urothelial barrier against the passing of infections.

These layers are surrounded by three layers of muscle fibres arranged as an inner layer of fibres orientated longitudinally, a middle layer of circular fibres, and an outermost layer of longitudinal fibres; these form the detrusor muscle, which can be seen with the naked eye.

The outside of the bladder is protected by a serous membrane called adventitia.