Structure and function of lower urinary tract Flashcards
What is the structure of the lower urinary tract?
Includes bladder wall, detrusor muscle, stroma, and urothelium
The lower urinary tract is responsible for urine storage and elimination.
What are lower urinary tract symptoms (LUTS)?
Symptoms related to bladder function, including storage and voiding issues
LUTS can affect quality of life and may indicate underlying conditions.
What is the function of the detrusor muscle?
Responsible for bladder contraction during micturition
The detrusor muscle is smooth muscle arranged in bundles.
What is the role of the urothelium?
Functions as a barrier and involved in afferent signaling
The urothelium is a multilayered epithelium with umbrella cells.
What is the lamina propria?
A layer of connective tissue supporting the urothelium
It is involved in the communication between the urothelium and detrusor.
What is the function of the bladder as a compliant reservoir?
Stores urine while maintaining constant pressure despite volume increase
The bladder’s visco-elastic properties allow for this function.
What triggers afferent neurons to sense bladder fullness?
Increase in wall tension during bladder filling
This signals to the brainstem and higher centers about the bladder state.
What is volitional micturition?
The voluntary act of voiding urine
It involves coordination of detrusor contraction and urethral relaxation.
What is the role of the pontine micturition center?
Modulates the spino-bulbar reflex for micturition
Barrington’s nucleus is a key area for this modulation.
What is the significance of wall tension in micturition?
Rises to trigger afferent signals to the pontine micturition center
This initiates a positive feedback loop for bladder contraction.
What neurotransmitter is primarily involved in excitatory neurotransmission for bladder function?
Acetylcholine (Ach)
Cholinergic signaling is crucial for detrusor contraction.
What role does nitric oxide play in bladder function?
Facilitates relaxation of the bladder neck and external urethral sphincter
This relaxation is essential for normal voiding.
True or False: GABA and glycine are excitatory neurotransmitters in bladder activity.
False
GABA and glycine act as inhibitory neurotransmitters.
What happens during spinal cord injury at S2-S3?
Loss of central inhibition leading to reflex voiding
This affects the pelvic parasympathetic nerves and pudendal nerve.
Fill in the blank: The bladder is highly _______ to accommodate varying volumes of urine.
compliant
Compliance allows for bladder pressure to remain stable.
What are the components of the bladder wall?
- Urothelium
- Detrusor muscle
- Stroma
- Adventitia/Serosa
Each component plays a role in bladder function and structure.
How often does the normal person urinate?
4-5 times per day, depending on input
How much urine does the normal person pass in one void?
300-400mls
What initiates voiding when the bladder contains approximately 300mls?
Social convenience
What is the purpose of a Frequency/Volume Chart?
To collect urinary habits data from the patient
What does a Bladder Diary monitor?
Input and Output
What are STORAGE LUTS?
- Urgency
- Frequency
- Nocturia
- Urinary incontinence (UI)
What are VOIDING LUTS?
- Hesitancy
- Poor flow
- Intermittency
- Terminal dribbling
- Frequency
- Nocturia
What is polyuria and what conditions should be considered?
Increased urinary production; consider DM/DI and excess fluid intake
What is nocturia?
Nocturnal frequency of urination, normal is <2 times per night
What factors can contribute to nocturnal polyuria?
- Ageing bladder
- Bladder outlet obstruction (BOO)
- Dietary habits
What does decreased force of micturition indicate?
Usually secondary to bladder outlet obstruction or underactive bladder
Define hesitancy in urinary function.
Delay in start of micturition
What is the definition of incontinence?
Involuntary loss of urine that is a social or hygienic problem and is objectively demonstrable
What is urge incontinence (UUI)?
Involuntary loss of urine associated with a strong desire to void
What is stress incontinence (SUI)?
Involuntary loss of urine when intra-abdominal pressure rises without detrusor contraction
What is the purpose of taking a history and urinary chart in assessment?
To gather information on urinary symptoms
What does the International Prostate Symptom Score (IPSS) consist of?
7 questions regarding urinary symptoms and a quality of life score
What scores indicate mild, moderate, and severe symptoms on the IPSS?
- 0-7: Mild
- 8-19: Moderate
- 20-35: Severe
What is the function of a UroFlowMeter?
Measures urine flow rate
What do pressure transducers measure during urodynamic assessment?
Pressure from bladder and rectum during filling and voiding
Fill in the blank: Nocturnal polyuria is defined as the production of more than ______ of 24-hour urine output between midnight and 0800.
one third
What is the significance of the bladder diary?
It is the most informative chart for monitoring urinary habits
What is the effect of ageing on renal concentrating ability?
Decreases with age, leading to increased urine production at night
What is the normal volume infused in the lower urinary tract?
400ml
What are the two main phases of urinary function?
Filling phase and Voiding phase
What is the diagnosis when there are no unstable contractions during filling?
Bladder outlet obstruction
What symptoms indicate bladder outlet obstruction?
Very high pressure and low flow during voiding, symptoms of outflow obstruction
What condition is described as ‘The bladder is an unreliable witness’?
Bladder outlet obstruction
What are the management options for Over-active bladder?
- Lifestyle changes
- Anti-muscarinics (Solifenacin, Fesoterodine, Oxybutynin)
- Selective β-3 adrenoreceptor agonist (Mirabegron)
- Intradetrusor Botox
What is the management for Stress Incontinence?
- Pelvic floor exercises
- Weight loss
- Surgery (autologous rectus abdominis sling, artificial sphincter)
What medical therapies are used for Bladder Outlet Obstruction?
- Alpha-blockers (Tamsulosin)
- 5ARI (Finasteride)
- Surgery (TURP, laser prostatectomy)
Fill in the blank: Symptoms of outflow obstruction may lead to _______.
Bladder failure
What is a potential consequence of chronic retention?
Renal failure
What are the key objectives in the study of the lower urinary tract?
- Structure of lower urinary tract
- Normal function
- Normal neurophysiology
- Lower urinary tract symptoms (LUTS)
- Assessment of LUTS
- Management of LUTS
True or False: Storage symptoms may come first before voiding symptoms.
True
What is the relationship between detrusor decompensation and urinary symptoms?
Detrusor decompensation can lead to residual urine and chronic retention.
What does the term ‘unstable’ refer to in the context of urinary function?
Unstable refers to unpredictable contractions during the filling phase.
