Session 8 - Physiology Of Micturition Flashcards
Name the layers of the bladder wall
- Transitional epithelium
- Lamina Propia
- Submucosa
- Detrusor Muscle
- Adventitia
How many layers make up the detrusor muscle and what are they?
3:
- Inner Longitudinal
- Middle Circular
- Outer Longitudinal
Which of the urethral sphincters is under voluntary control?
External Urethral Sphincter
Describe the parasympathetic innervation of the detrusor muscle
- Pelvic Nerve (S2-4)
- Uses Ach on M3 receptors
- Causes contraction of the muscle
Describe the sympathetic innervation of the detrusor muscle
- Hypogastric nerve (T10-L2)
- Uses NA on Beta 3 receptors
- Causes relaxation
Why are the many folds of the bladder wall crucial to allow efficient filling?
- The folds allow the bladder to distend greatly upon filling
- The pressure does not rise at first as the bladder fills
- hence we don’t need to urinate as soon as the bladder holds some urine
- allows the bladder to act as a storage space for urine
What is stress urinary incontinence?
Involuntary leakage on effort or excretion or on speeding or coughing
What is urge urinary incontinence?
Involuntary leakage, accompanied by or immediately produced by urgency
What is mixed urinary incontinence?
Involuntary leakage, associated with urgency + exertion, effort, sneezing or coughing
What is the general trend of urinary incontinence and age?
Steadily increases with age
Give some risk factors for Urinary incontinence
- Childbirth
- UTI
- Pelvic prolapse
- age
- Smoking and Obesity
- Raised Intra-ab pressure or neurological abnormalities
What examinations would you perform if you suspected urinary incontinence?
- Height and weight
- Ab exam
- Digital Rectal exam
- External Genitalia stress test in females
What investigations might you make if you suspect urinary incontinence?
- Urine dipstick (MANDATORY)
- Bladder diary, frequency-volume charts, post micturition residual volume
- pad tests
- cystoscopy
Give some lifestyle interventions you might suggest to combat urinary incontinence
- Modify fluid intake and weight loss
- Stop smoking and reduce caffeine intake
- avoid constipation
- timed voiding
How does Oxybutynin work to help with Urinary incontinence?
- Acts on muscarinic receptors including M3
- Acts as an Anticholinergic
- Prevents Ach causing detrusor muscle contraction
