Urinary Bladder Anatomy: Layers, Musculature, and Support

The bladder is a distensible, muscular reservoir.

Wall Layers (inner → outer)

• Urothelium (transitional epithelium): Impermeable umbrella cells (plaques) prevent urine absorption; accommodates stretching.
• Lamina propria: Connective tissue, vasculature, nerves.
• Muscularis propria (detrusor muscle): Three smooth‑muscle layers: inner longitudinal, middle circular, outer longitudinal. Contracts for voiding.
• Adventitia/serosa: Connective tissue; peritoneal covering on dome only.

Support

Pelvic floor muscles (levator ani, pubococcygeus) and endopelvic fascia maintain position and continence.

Urothelial integrity and detrusor compliance are essential for storage; coordinated sphincter relaxation and detrusor contraction enable voiding.