Normal physiology and pathophysiology of the lower urinary tract

Table of Contents

1. Introduction
2. Bladder Filling
3. Voiding
4. Pathophysiology of micturition
5. Impact of bladder symptoms and urinary incontinence
6. Summary
7. References

Pathophysiology of micturition

Urinary symptoms may relate to problems of storage, bladder emptying, post-micturition symptoms or a combination of these.

Urinary Signs and Symptoms (adapted from Abrams et al, 2002)

Storage symptoms

- Increased daytime frequency (> 8 times per day)

- Nocturia: waking once or more at night to void.

- Urgency: a sudden compelling desire to pass urine which is difficult to defer.

- Urinary incontinence

Emptying symptoms

- Slow, split or intermittent stream

- Hesitancy

- Straining

- High post-void residual

- Terminal dribble: a prolonged final part of micturition, when the flow has slowed.

Post-micturition symptoms (experienced immediately after micturition)

- Feeling of incomplete emptying

- Post Micturition Dribble: the involuntary loss of urine immediately after finishing passing urine.

Task 3

1

Referring to the diagram above - Urinary Signs and Symptoms - in your experience, which type of bladder symptoms are most likely to necessitate catheterisation? Click 'Check Answer' when you've finished. Emptying symptoms are most likely to necessitate catheterisation. Problems with bladder storage or emptying often result in urinary incontinence.

Task 4

2	Give a definition of Urinary Incontinence (UI). Click 'Check Answer' when you've finished. There are many definitions of UI cited in the literature, but the key feature in all of them is that the urine loss is "involuntary".

The International Continence Society (ICS) defines urinary incontinence as "the complaint of any involuntary leakage of urine" (Abrams et al, 2002; p168).

There are a number of identified types of urinary incontinence (Abrams et al, 2002) (Table 2). Select the empty cells on the right of the table to find out more.

Table 1: Types of urinary incontinence

Task 5

3	Referring to table 1, what type of urinary incontinence is most likely to lead to catheterisation? Click 'Check Answer' when you've finished. Overflow Incontinence, which is often the result of acute or chronic urinary retention.

The different types of urinary incontinence are symptoms of an underlying problem and have a variety of different causes (Table 2).

Table 2: Common types of urinary incontinence and their common causes (Adapted from Wells et al, 2011)