Flashcards in Session 8 - Micturition and incontinence Deck (70):
Give the three main parts of the bladder
Give the histological layers of the bladder wall
• Transitional epithelium
• Lamina propria
• Detrusor muscle
What is the body/fundus of the bladder?
• Temporary store of urine
What is the trigone?
• Ureteric orifices and internal urethral orifice are at the angles of a triangle
What is the neck of the bladder?
• Connects the bladder to the urethra
Outline the structure of the detrusor urinae muscle
• Made from a meshwork of muscle fibres in roughly 3 layers
○ Inner longitudinal
○ Middle circular
○ Outer longitundinal
Why does the bladder have three layers of muscle?
• Arrangement of muscle gives the bladder strength regardless of direction it is being stretched in
What is detrusor muscle supplied by?
• Autonomic nervous system, not under voluntary control
Spinal nerve supply is bilateral
What is the internal urethral sphincter?
• Continuation of the detrusor muscle and made of smooth muscle
• Physiological sphincter at the bladder neck
What is a physiological sphincter?
• A sphincter which is indistinguishable from surrounding tissue at autopsy
What is the primary muscle of continence?
• Internal Urethral Sphincter
What is the external urethral sphincter
• Anatomical sphincter
○ Localised circular muscle thickening to facilitate action
What is the external urethral sphincter derived from?
• Pelvic floor muscles
What type of muscle is the external sphincter?
• Skeletal muscle under somatic, voluntary control
• Contracts to constrict urethra and hold in urine
What are the two innervations of the detrusor?
Outline the parasympathetic innervation of the detrusor
• Pelvic nerve (S2-S4)
• Ach - M3 receptors
Outline the sympathetic innervation of the detrusor?
• Hypogastric nerve (T10-L2)
• NA -> B3 receptors
What is the innervation of the internal urethral sphincter?
• Hypogastric nerve (T10 - L2)
• NA -> a1 receptors
• Pelvic nerve
What is the innervation of the external urethral sphincter?
• Pudendal nerve (S2-S4)
• Spinal motor outflow from Onof's nucelus of the ventral horn of the spinal cord
• Ach -> Nicotinic teceptor
What are the four main functions of the nervous system in relation to the bladder?
• Provide sensation of bladder filling and pain
• Allow the bladder to relax and accomodate to increasing volumes of urine
• To initiate and maintain voiding so bladder empties completely, with minimal residual volume
• To provide an integrated regulation of the smooth muscle
and skeletal muscle sphincters of the urethra
What prevents retrograde ejaculation in men?
• Prostatic urethra
Give the nerve roots which control urine storage
• L1 & L2
Give the nerve roots which control bladder voiding
What are the two phases of the bladder?
What occurs in the filling phase?
• The bladder relaxes and accommodates increasing volumes of urine
• The urethral sphincters increase their tone to maintain continence
What volume of urine is usually required to cause the urge to urinate?
What is the overall capacity of the urinary bladder?
• 350 - 750ml
Outline the nervous pathway which is activated once bladder has a volume of >400ml and urge to urinate arises
• Brain micturition centres -> Spinal micturition centres -> parasympathetic neurones -> Pelvic nerve -> Contraction of detrusor muscle -> Rise in intravesicular pressure
What occurs once there is a rise in intravesicular pressure in the bladder?
• Cerebral context makes a concious, executive decision to urinate by reducing sympathetic stimulation to the external urethral sphincter
What causes feeling of pain/temperature in bladder as it reaches 400ml filling?
• Afferent nerves from the bladder wall start to signal the need to void by producing pain/temperature
Outline the nervous pathways which is activated in the filling phase
• Brain continence centres -> Spinal continence centres -> Sympathetic neurones -> Hypogastric nerve
What does an increase of sympathetic stimulation to the bladder cause in the filling phase
• Hypogastric nerve stimulates relaxation of detrusor and contraction of the internal urethral sphincter
• Cerebral cortex makes concious executive decision no to urinate by increasing somatic stimulation to the external urethral sphincter
What three things must occur for bladder not to empty?
• Relaxation of detrusor
• Contraction of internal urethral sphincter
• Contraction of external urethral sphincter
Give four types of urinary incontinence
• Stress Urinary Incontinence
• Urge Urinary incontinence
• Mixed Urinary Incontinence
• Overflow Incontinence
What is stress urinary incontinence?
• Involuntary leakage on effort or exertion, or on sneezing or coughing
What is urge urinary incontinence?
• Involuntary leakage, accompanied by or immediately proceeded by urgencu
What is mixed urinary incontinence?
• Involuntary leakage associated with urgency and exertion, effort, sneezing or coughing
What is overflow incontinence?
• Retention of urine causing the bladder to swell. Can be low pressure and pain free
Which type of urinary incontinence has the highest incidence?
• Stress urinary incontinence
Give three categories of risk factors for urinary incontinence
• Obs and Gyny
Give three obs and gyny risk factors for urinary incontinence
• Pregnancy and childbirth
• Pelvic surgery
• Pelvic prolapse
Give three predisposing risk factors for urinary incontinence
• Family predisposition
• Anatomical abnormality
Give three promoting risk factors for urinary incontinency
• Cognitive impairment
What is an important physiological factor in maintaining continence?
• Support of the urethra by the muscles and ligaments of the pelvic floor are important for the efficiency of the sphincter mechanisms of the urethra that enables continence
Outline history taking from a patient with a history of Urinary incontinence
• Ask to record the amount of fluid they pass for two or three days
• Work out the number of pads that the patient has to use per day to cope with urine leakage
• Assess whether leakage continous or intermittent
• What precipitating factors are present (coughing/sneezing)
What can make urgency and frequency of micturition worse?
• Intravesicular inflammatory conditions due to UTI, stone in the bladder or tumour
How can past medical history assist in the assesment of UTI's?
• Previous surgery of the pelvic floor
• Childbirth can cause sphincter damage
Outline what information must be gathered in a urinary examination
• Abdominal exam to exclude palpable bladder
• Digital rectal examination (DRE)
○ Limited neurological examination
• (Females) External genitalia
(Female) Vaginal exam
What investigations should be done in the case of urinary incontinence?
○ Urine dipstick
• Basic non-invasive urodynamics
○ Frequency volume chart
○ Bladder diary
○ Post micturition residual volume
○ Invasive urodynamics
○ Pad tests
What does management of urinary incontinence depend on?
• Symptoms patients have
• Degree of inconvenience they suffer as a result
• Previous or current treatments
Effects of treatments on other symptoms they may have
Outline conservative management of urinary incontinence
• Modify fluid intake
• Weight loss
• Stop smoking
• Decrease caffeine intake (UUI)
• Avoid constipation
• Timed voiding – fixed schedule
What treatment can be give to patients who fail conservative management but are unsuitable for surgery?
• Indwelling catheter
○ Urethral or suprapubic
• Sheath device
○ Analagous to an adhesive condom attached to a catheter tubing and bag
• Incontinence pads
Give specific management of Stress Urinary Incontinence
• Pelvic floor muscle training
• 8 contractions, 3x a day
• At least 3 months duration
• Void bladder, stop stream ß use those muscles in pelvic floor training
Give specific management of a urge urinary incontinence?
• Bladder training
• Schedule of voiding
○ Void every hour during the day
○ Must not void in between – wait or leak
○ Intervals increased by 15-30 minutes a week until interval of 2-3 hours
• At least 6 weeks of training needed
Give three pharmacological managements of patients with urinary incontinence
What is duloxetine?
• A combined noradrenaline and serotonin uptake inhibitor
• Increases the activity od the external urethral sphincter during the filling phase
• Offered as alternative to surgery
What is an anticholinergic?
• Act on muscarininc receptors, including the M3 receptors that cause the detrusor muscle to contract.
What is a downside of using an anti-cholinergic to treat urinary incontinence?
Many side effects due to effect on muscarinic receptors
Why is botulinim toxin sometimes used?
• A potent buiological neurtoxin that inhibits Ach release. Prevents detrusor muscle contraction as pelvi nerve cannot release Ach to act on the M3 receptors
What are the two main types of surgery in females for urinary incontinence?
• permanent intention
• Temporary intention
Give three types of permanent intention surgery in females
• Low tension vaginal tape
• Open retropubic suspension procedures
• Classic fascial sling procedure
What is low tension vaginal tape?
• Common, minimally invasive surgery
• Success rate of >90%
• Supports mid urethra with a polyprophylene mesh
What is open retropubic suspension procedure?
• Corrects the anatomical position of the proximal urethra and improves urethral support
What is the classic fascial sling procedure?
• Supports urethra and increases bladder outflow resistance
• Involves autologus transplantation of the fascia late or rectus fascia
Give a temporary female treatment for urinary incontinence?
• Intramural bulking agents improve the ability of the urthera to resist abdominal pressur eby improving urethral coaptation. This is achieved by injetions of autologous fat, silicone, collagen or hylauron-dextran polymers
Give two surgical treatments in men for UI
• Artificial urinary sphincter
• Male sling procedure
Outline the insertion of an artificial urinary sphincter in amales
• Treatment for urethral sphincter deficiency
Cuff is a mechanical device that stimulates the action of a normal sphincter to cicrumferntially close the urethra
Give three problems involved in the insertion of an artificial urinary sphincter
What is a male sling procedure?
• Corrects stress urinary incontinence in males
Bone anchored tape attached to urethra