Ageing 7: Renal & Urological Flashcards
(16 cards)
Describe neuronal control of micturition, including nerves and corresponding nerve roots
- Parasympathetic (ACh) via pelvic nerve to contract detrusor; S2-S4
- Sympathetic (NA; why not A?) to IUS and destrusor via hypogastric nerve (H=Hypogastric=Hold on); T12-L2
- Somatic via pudendal nerve (ACh loss); S2-S4
When is the micturition reflex triggered vs when does it actually propagate?
- Triggered in response to bladder stretch
- In inappropriate circumstances, inhibitory neural input from the PMC stops the reflex
- Only triggered when there’s stretch && no cortical inhibition
Which receptors does ACh act on in the external urethral sphincter vs detrusor muscle + how to remember?
- Detrusor = M3
- EUS = nicotinic
(We take in nicotine voluntarily, but don’t voluntarily want to build muscle; too hard)
Where is the decision to urinate made? How is this transmitted from central to peripheral nerves?
- Decision is made if the forebrain
- Travels to pons, where is deactivates pontine continence centre and activates pontine micturition centre
- This then results in relaxation of sphincters (inhibition of somatic + sympa) and contraction of detrusor (parasympa)
Recall the classification of LUTS
- Voiding (straining, weak flow, incomplete emptying)
- Storage (urgency, overflow incontinence, nocturia, incontinence)
Difference in LUTS patterns between men and women
- Storage LUTS (except incontinence) approx equal
- Incontinence more common in women (pregnancy + shorter urethra)
- Voiding symptoms more common in men (prostate)
Which type of LUTS is more commonly associated with systemic disease? What system diseases are they?
- Storage symptoms more commonly associated
- Assoc with cardiometabolic disease, OSA, depression, and inflammatory disorders
Fundamental pathophysiology of storage LUTS (+ useful analogy for memory)
- Like hypertension of the bladder
- Caused by decreased bladder wall compliance, increase contractility at lower volumes
- Assoc w/ systemic conditions
Fundamental pathiphysiology(?ies) of voiding LUTS
- Detrusor underactivity OR bladder outlet obstruction
- Most commonly a max due to BPH
Causes of storage LUTS
- Heart failure (why?)
- T2DM (why?)
- Diabetes insipidus (why?)
- Bladder tumours
Which factors determine whether or not LUTS remit?
- Decreased abdo fat mass
- Decreased psychological stress
- Being married
- Lower blood pressure
- Treating obstructive sleep apnoea
- Increased physical activity
What changes to the kidneys occur during aging?
- Decreased renal mass (↓ nephron number)
- Reduced renal flow (↓ compliance, ↓ vascular stiffness)
- Reduced GFR
- Altered electrolyte metabolism (↑ risk of disturbance)
- Reduced renal autoregulation (WIT?)
BPH Pathophys/symptoms
- Pathophys: increase in cell number in the prostate driven by hormones such as DHT
- Symptoms: voiding symptoms (weak stream, incomplete voiding, dribbling)
How to determine if BPH is predominant cause of LUTS
- DRE (is it enlarged)
- Neuro exam (conditions such as CHF, T2DM, or diabetes insipidus that could explain symptoms?)
- Bladder diary to determine if weak stream (↑ likelihood of weak stream in this instance)
Medical vs surgical treatment of BPH. When do we choose which?
- Medical: alpha blockers (why?), 5 alpha reductase inhibs
- Surgical: TURP (WIT?), laser enucleation, stents
- Medical indicated when affecting quality of life, and surgical indicated mostly when medical fails/severe cases
Risks of medical vs surgical treatment of BPH
- Medical: cardio effects (alpha blockers; why?), sexual dysfunction (both drugs; why?)
- Surgical: sexual dysfunction
