The urinary bladder is a hollow organ located in the pelvis that stores urine. An empty bladder has a tetrahedral shape while a distended bladder is ovoid. The average bladder capacity is 220 ml and painful sensations start above 450 ml of urine. The bladder parts include the fundus, neck, and trigone, which is a triangular area at the bladder base. Histologically, the bladder contains transitional epithelium, lamina propria, submucosa, detrusor muscle layers, and serosa to store and expel urine in a controlled manner.

1. URINARY
BLADDER
DR.HIRAK DAS

2. URINARY
BLADDER
• A hollow organ that stores urine
• Location:
– Empty bladder: Pelvis
– Distended bladder:
Abdominopelvic
• Shape:
– Empty bladder: Tetrahedral
– Distended bladder: Ovoid
• Capacity
– 220 ml (average)
– Painful sensation start when
amount reach above 450 ml
– Above 800 ml, micturition goes
beyond involuntary control.
– Beyond 1 litre (approx): Bladder
will rupture Anatomical
capacity.

3. PARTS OF AN EMPTY BLADDER:
FUNDUS OR BODY
– Apex
– Base
– 3 surfaces:
• Superior surface
• 2 Inferolateral Surface
– 4 Borders:
• Anterior
• Posterior
• 2 Lateral
 NECK

4. PARTS OF AN DISTENDED BLADDER:
• 4 SURFACES:
– Anteroinferior surface
– Posterosuperior surface
– 2 lateral surfaces
• NECK
• Trigone
– Triangular area on inner aspect of base of bladder

5. Histological
structures
• Mucosa
– Thrown into folds.
– Folds disappear in
distended bladder
– Epithelium
• Transitional epithelium
• Urine proof
– Lamina propria
• Submucosa
• Muscular layer
– Detrusor
• Outer longitudinal
• Middle circular
• Inner longitudinal
– Trigone
• Serosa/Adventitia