Summary ANATOMY OF THE URETHRA AND BLADDER

BLADDER AND URETHRA OBJECTIVES • The urinary bladder is a muscular reservoir of urine, lying in the anterior part of the pelvis. • It is commonly involved in clinical conditions such as retention of urine, cystitis (inflammation of the urinary bladder), calculus, disorder of micturition, and cancer. • Hence, its anatomy is of immense importance to clinicians. LOCATION • The urinary bladder is situated in the anterior part of the lesser pelvis immediately behind the pubic symphysis and in front of rectum in male and uterus in the female . • The location of the urinary bladder varies with the amount of urine it contains and with age. • When the bladder is empty it lies entirely within the lesser pelvis but when it becomes distended with urine, it expands upward and forward into the abdominal cavity. Size and Shape • The size and shape of the urinary bladder vary according to the amount of urine that it contains. • It is tetrahedral in shape when empty and ovoid in shape when distended. Capacity • Normally in adult male the capacity varies from 120 to 320 ml. • The mean capacity is about 220 ml. • 1. An amount of urine beyond 220 ml causes a desire to micturate but the bladder is usually emptied at about 250–300 ml. Cont… • The filling of urine up to 500 ml may be tolerated but beyond this, it causes pain due to tension of its wall. • On collection of urine about 800 ml, the micturition is beyond one’s voluntary control.