Female Lower Urinary Tract Flashcards
What is the detrusor muscle?
The smooth muscle wall of the bladder
Capacity of the bladder?
500ml
When do you first feel the urge to void (ml)?
200ml
Which types of nerves aid voiding?
Parasympathetic
Which types of nerves prevent voiding?
Sympathetic
What is the voiding reflex?
Afferent fibres respond to bladder wall distension and pass to spinal cord
Efferent parasympathetic fibres pass back to the detrusor muscle and cause contraction and enable opening of bladder neck
Efferent sympathetic fibres to the detrusor are inhibited
At what level is the ‘micturition reflex’ controlled?
The pons
What is continence dependent on?
The pressure in the urethra being greater than that in the bladder
What influences bladder pressure?
Detrusor pressure and intra-abdominal pressure
What influences urethral pressure?
Inherent urethral muscle tone External pressure (pelvic floor) Intra-abdominal pressure
Does bladder pressure increase as it fills?
No because the detrusor muscle expands
Why does coughing not normally cause incontinence?
Coughing increases abdominal pressure but transmits it equally to the bladder and upper urethra because both lie within the abdomen
When does micturition occur?
When bladder pressure exceeds urethral pressure
How is micturition achieved?
Voluntarily by a simultaneous drop in urethral pressure (partly due to pelvic floor relaxation) and an increase in bladder pressure due to detrusor muscle contraction
What are the 2 causes of female incontinence?
Uncontrolled increases in detrusor pressure increasing bladder pressure beyond that of the normal urethra
Increased intra-abdominal pressure transmitted to the bladder but not the urethra, because the upper urethra neck has slipped from the abdomen
What is the most common cause of uncontrolled increases in detrusor pressure?
‘Overactive bladder’ (OAB) or urinary urge incontinence
Most common cause of increased intra-abdominal pressure?
Urinary stress incontinence
Urinary incontinence definition?
Involuntary urine leakage, which can be divided broadly into stress incontinence and urge incontinence
Daytime frequency definition?
Number of times a woman voids during waking hours. Normally between 4 to 7. Increased daytime frequency is defined as occurring when a patient perceives that she voids too often by day
Nocturia definition?
Waking at night one or more times to void. Up to the age of 70 years, more than 1 void is considered abnormal
Nocturnal enuresis definition?
Urinary incontinence occurring at night
Urgency definition?
Sudden compelling desire to pass urine, which is difficult to defer. Most frequently secondary to detrusor overactivity, although inflammatory bladder conditions such as cystitis may present with this
Where is bladder pain felt?
Suprapubically or retropubically
When does bladder pain typically occur?
Occurs with bladder filling and is relieved by emptying
What is bladder pain indicative of?
Intravesical pathology e.g. interstitial cystitis or malignancy
Urethral pain is felt where?
The urethra
Dysuria definition?
Pain experienced in the bladder or urethra on passing urine, frequently associated with UTIs
Haematuria definition?
Presence of blood in the urine. EIther microscopic or macroscopic (frank)
Always significant and warrants further Ix
Ix of the urinary tract?
Urine dipstick tests Urinary diary Postmicturition US or catheterisation Urodynamic studies, cystometry Ultrasound Abdominal x-rays CT urogram Methylene dye test Cystoscopy
What do urine dips test for?
Blood, glucose, protein leucocytes, nitrites
What do nitrites in urine indicate and what should be done?
Presence of infection; send urine sample to microscopy and culture
What does glycosuria suggest?
Diabetes
What does haematuria suggest?
Bladder carcinoma or calculi
What do postmicturition US or catheterisation do?
Exclude chronic retention of urine
What are Urodynamic studies, cystometry?
Necessary prior to surgery for stress incontinence or for women whose overactive bladder Sx do not respond to medical therapy
Cystometry directly measures, via a catheter, the bladder (vesical) pressure whilst bladder is filled and provoked with coughing. Pressure transducer is also placed in rectum (or vagina) to measure abdo pressure
What does US exclude?
Incomplete bladder emptying, checks for congenital abnormalities, calculi (solid particles in urinary system) and tumours and detects cortical scarring of kidneys
What does abdo x-ray diagnose?
Foreign bodies and calculi
What does CT test?
Using contrast, integrity and route of ureter are examined
What does methylene dye test test?
Blue dye is inserted into bladder. Leakage from places other than the urethra e.g. fistulae can be seen
What does cystoscopy exclude?
Tumours Stones Fistulae Interstitial cystitis BUT gives no indication of bladder performance
