ATI Pathophysiology Practice Exam

What is the average capacity of a normal adult bladder before involuntary micturition typically occurs?

1. 300 mL

2. 450 mL

3. 600 mL

4. 750 mL

The correct answer is: 600 mL

The average capacity of a normal adult bladder before involuntary micturition typically occurs is around 400 to 600 mL. This range reflects the bladder's ability to store urine efficiently until the urge to void becomes significant. At about 300 mL, some individuals might start to feel the need to urinate, but it is not until the bladder stretches to a greater capacity, closer to 450 mL or more, that the sensation becomes more pressing and the reflex to void is triggered. Therefore, 600 mL is at the higher end of this normal range, signifying that while some may feel the urge at lower levels, the bladder can comfortably hold this amount before involuntary micturition is likely to occur. This physiological understanding is vital for grasping normal urinary function and the pathophysiology of urinary disorders.