GU Flashcards
What anatomical structures make up the lower urinary tract?
Bladder -> bladder neck -> prostate gland -> urethra and urethral sphincter.
Give 4 functions of the lower urinary tract.
- Storage of urine.
- Converts the continuous process of excretion to an intermittent, controlled and volitional process.
- Prevents leakage of stored urine.
- Allows rapid, low pressure voiding.
Is the detrusor muscle relaxed or contracted during storage?
Relaxed.
Is the detrusor muscle relaxed or contracted during voiding?
Contracted.
Is the urethral sphincter relaxed or contracted during storage?
Contracted.
Is the urethral sphincter relaxed or contracted during voiding?
Relaxed.
What type of epithelium lines the bladder?
Urothelium (transitional epithelium) - pseudo-stratified.
Describe the physiology of micturition.
The bladder fills and stretch receptors are stimulated. Afferent impulses stimulate parasympathetic action of detrusor muscle; it contracts. The urethral sphincters relax; this is mediated by inhibition of the neurones to them. The PAG is stimulated.
What are lower urinary tract symptoms (LUTS) in men > 50 likely to be due to?
Benign prostatic enlargement.
LUTS: give 3 symptoms of storage problems.
- Frequency.
- Urgency.
- Nocturia.
LUTS: give 4 symptoms of voiding problems.
- Straining.
- Hesitancy.
- Incomplete emptying.
- Poor flow.
What might dysuria suggest?
Inflammation.
What investigations might you do on someone who presents with LUTS.
- Urinary tests e.g. dipstick.
- Urinary flow: maximum flow rate and residual volume are important.
- Symptom assessment: international prostate scoring system.
- Blood tests e.g. PSA, U+E.
Give 3 causes of nocturnal polyuria.
- Habitual.
- Congestive cardiac failure.
- Sleep apnea.
Describe the treatment for someone who presents with mild LUTS.
Reassurance, watch and wait.
Describe the treatment for someone who presents with moderate LUTS.
- Fluid management, avoid caffeine.
- Bladder drill.
Give 2 pharmacological therapies used in the treatment of moderate to severe LUTS.
- Alpha-1-blockers e.g. tamulosin.
- 5-alpha-reductase-inhibitors.
How do alpha-1-blockers work in the management of LUTS?
They cause vasodilation and so reduced resistance to bladder outflow.
Give 2 potential side effects of tamulosin.
Tamulosin is an alpha-1-blocker used in the treatment of LUTS. 2 side effects include hypotension and retrograde ejaculation.
How do 5-alpha-reductase-inhibitors work in the management of LUTS?
They inhibit the conversion of testosterone to dihydrotestosterone and so reduce prostate size.
Give a surgical treatment for BPE.
TURP.
Give 5 potential consequences of untreated LUTS.
- Bladder calculi (stones).
- UTI.
- Urinary incontinence.
- Reduced QOL.
- Acute urinary retention.
Give 3 symptoms of acute urinary retention.
- PAINFUL!
- Sudden onset.
- > 500ml of urine in bladder.
Name a rare but serious cause of acute urinary retention.
Spinal cord compression.
What investigations might you do in someone with acute urinary retention?
- Clinical examination: palpable bladder?
- MRI.
- Bloods.
- Neurological tests; could be a sign of spinal cord compression e.g. pain in back, loss of anal reflex, leg weakness.
Describe the treatment for someone with acute urinary retention.
Reassurance, catheterise, pain relief.
What nerve fibres do cavernous nerves carry?
Parasympathetic: S2-4.
Sympathetic: T11-L2.
Describe the physiology of an erection.
- Parasympathetic stimulation.
- Arteriolar dilation.
- Smooth muscle relaxation.
- Testosterone.
What chemical compound is responsible for the smooth muscle relaxation that is required for an erection?
Nitric oxide (NO). It causes a fall in cytoplasmic calcium -> smooth muscle relaxation.
What are the 2 main causes of erectile dysfunction?
- Organic e.g. vasculogenic, neurogenic, hormonal, anatomical.
- Psychogenic.
Give 3 characteristics of psychogenic erectile dysfunction.
- Sudden.
- Situational.
- Younger males affected.
Give 4 risk factors for erectile dysfunction.
- Obesity.
- Lack of exercise.
- Smoking.
- Diabetes mellitus.
What is the non-pharmacological management of erectile dysfunction?
- Lose weight, stop smoking.
- Education and counselling of patient and partner.
What is the first line pharmacological management of erectile dysfunction?
Phosphodiesterase inhibitors e.g. viagra, cialis. They cause vasodilation and so increase arterial blood flow to the penis.
What is the second line pharmacological management of erectile dysfunction?
- Intracavernous injections.
- Vacuum devices.
What is the third line pharmacological management of erectile dysfunction?
Penile prosthesis implantation.
What is priapism?
Prolonged erection, lasting for >4 hours.
What is a potential consequence of priapism?
Permanent ischaemic damage.
Where might a transitional cell carcinoma arise?
- Bladder (50%).
- Ureter.
- Renal pelvis.
Describe the epidemiology of transitional cell carcinoma.
- M:F = 3:1.
- Age > 40 y/o.
Give 5 risk factors for transitional cell carcinoma.
- SMOKING.
- Occupational exposure e.g. working in rubber factories (aromatic amines).
- Increasing age.
- Male gender.
- Family history.
Give 5 symptoms of transitional cell carcinoma.
- PAINLESS HAEMATURIA.
- Frequency.
- Urgency.
- Dysuria.
- Urinary tract obstruction.
Give 5 investigations that you might do in someone who you suspect has transitional cell carcinoma.
- Urine dipstick.
- Blood tests.
- Flexible cystoscopy = diagnostic.
- Imaging of upper urinary tract e.g. CT IVU.
- TURBT.
Give 2 potential risks of flexible cystoscopy.
- UTI’s.
- Problems passing urine.
Why would you want to image the upper urinary tract of someone with transitional cell carcinoma?
You image the UUT to confirm that there is no other TCC elsewhere in the urinary tract.
CT IVU, USS and XR can be used.
Why might you do a trans-urethral resection of bladder tumour (TURBT) in someone with TCC?
For histological and staging analysis.
What staging system is used for TCC?
TNM staging.
Describe the treatment for non-muscle invasive bladder cancer (CIS, Ta, T1).
- TURBT.
- Chemotherapy to reduce the risk of recurrence and progression to muscle invasion.
Describe the treatment for muscle invasive bladder cancer (T2, T3).
- Radical cystectomy = gold standard.
- +/- neo-adjuvant chemotherapy.
- Radical radiotherapy if not fit/unwilling to undergo cystectomy.
Describe the treatment for T4 TCC (invasion beyond the bladder).
- Palliative chemo/radiotherapy.
- Chronic catheterisation for pain.
Name a helminth that can cause squamous cell carcinoma of the bladder.
Schistosomiasis.
Give 5 functions of the kidney.
- Filters and excretes waste products from the blood.
- Regulates BP.
- Retains albumin.
- Reabsorption of Na, Cl, K, glucose, H2O, amino acids.
- Synthesises EPO.
- Converts 1-hydroxyvitaminD to 1,25-dihydroxyvitaminD.
Write an equation for GFR.
(Um X urine flow rate) / Pm.
- Um = concentration of marker substance in urine.
- Pm = concentration of marker substance in plasma.
What would you expect a typical GFR to be?
120ml/min.
Give an example of a marker substance used for estimating GFR.
Creatinine.
Estimating GFR: Give 3 essential features of a marker substance.
- Not metabolised.
- Freely filtered.
- Not reabsorbed/secreted.
Name a drug that can inhibit creatinine secretion. What is the affect of this on GFR?
Trimethoprim.
Serum creatinine rises and so kidney function (GFR) appears worse.
What is the affect on GFR of afferent arteriole vasoconstriction?
Decreased GFR.
What is the affect on GFR of efferent arteriole vasoconstriction?
Increased GFR.
Where in the nephron does the bulk of reabsorption occur?
At the proximal convoluted tubule.
What 7 things are reabsorbed at the PCT?
- Sodium.
- Chlorine.
- Potassium.
- Glucose.
- Water.
- Amino acids.
- Bicarbonate.
What is Fanconi syndrome?
Failure of the nephron to reabsorb essential ions. Sugar, amino acids and bicarbonate are therefore present in the urine.
Give 2 signs of Fanconi syndrome.
- Sugar in the urine.
- Acidotic due to bicarbonate in the urine.
- Rickets/osteomalacia.
Give 2 causes of Fanconi syndrome.
- Myeloma.
- Cystinosis.
What is the function of the counter current multiplication system?
It generates a hypertonic medullary interstitium for H2O reabsorption. Na+ moves out of the ascending limb which increases the medullary osmolality, H2O follows.
Which part of the loop of henle is permeable to H2O?
The descending limb is permeable to H2O.
Describe tubuloglomerular feedback.
Macula densa cells of the DCT lie between the AA and EA. They detect NaCl and use this as an indicator of GFR.
Macula densa cells detect a raised NaCl. What is the response?
AA constriction.
Macula densa cells detect a reduced NaCl. What is the response?
Renin secretion.
What 2 cell types are found in the nephron collecting duct?
Principal and intercalated cells.
What hormone is responsible for regulating sodium reabsorption?
Aldosterone.
Why might aldosterone secretion lead to hypokalaemia?
Aldosterone secretion leads to increased sodium reabsorption. Sodium reabsorption leads to increased potassium secretion and therefore hypokalaemia.
What is the affect of NSAIDs on the afferent arteriole of glomeruli?
NSAIDs inhibit prostaglandins and so lead to AA vasoconstriction = reduced GFR.
NSAIDs lead to a reduced GFR. Why?
NSAIDs inhibit prostaglandins and so lead to afferent arteriole vasoconstriction -> reduced GFR.
What is the affect of ACEi on the efferent arteriole of glomeruli?
ACEi cause EA vasodilation = reduced GFR.
Name 2 factors that govern renal potassium.
- Na+.
- Aldosterone.
What ion is responsible for volume control?
Sodium!
Name 2 hormones that increase sodium reabsorption.
- Aldosterone.
- Angiotensin 2.
Name a hormone that decreases sodium reabsorption.
ANP.
What is the function of EPO?
It stimulates the bone marrow -> RBC maturation.
Give 2 functions of calcitriol.
- Increased calcium and phosphate absorption from the gut.
- Suppression of PTH.
Why might someone with advanced CKD also have hyperparathyroidism?
Advanced CKD = calcitriol deficiency. Calcitriol suppresses PTH therefore deficiency -> hyperparathyroidism.
What triggers PTH secretion?
Low serum calcium.
Give 3 ways in which PTH increases serum calcium.
- Increased bone resorption.
- Increased reabsorption of calcium at the kidneys.
- Stimulates 1-hydroxylase -> 1,25-dihydroxyvitaminD -> increased calcium absorption from the intestine.
Name 2 hormones secreted from the posterior pituitary gland.
- ADH.
- Oxytocin.
Describe the function of ADH.
ADH acts on the collecting ducts. It increases insertion of aquaporin 2 channels leading to H2O retention.
Give 3 factors that stimulate renin release.
- Sympathetic stimulation.
- Decreased BP.
- Decreased Na detected by macula densa.
Give 3 functions of ANP.
- Renal vasodilator.
- Inhibits aldosterone.
- Closes ENaC (decreased reabsorption of Na+).
Where on the nephron does aldosterone act?
On the collecting ducts.
Describe aldosterone action.
Aldosterone acts on the collecting ducts. It increases ENaC and H+/K+ pumps. There is increased Na+ absorption and K+ secretion -> H20 retention -> increased BP.
Define urinary tract infection.
Inflammatory response of the urothelium to bacterial invasion, usually associated with bacteriruria and pyuria.
Name 3 UTI causative organisms.
- Uropathogenic strains of E.coli (UPEC) - 82%.
- CNS e.g. s.saprophyticus.
- Proteus mirabilis.
- Enterococci.
- Klebsiella pneumonia.
Briefly describe the epidemiology of UTI’s.
More common in women due to short urethra and its proximity to the anus.
Describe the pathophysiology of UTI’s.
Organisms colonise the urethral meatus and ascend via the transurethral route.
What can facilitate bacteria ascent into the urinary tract via the urethra?
- Sexual intercourse.
- Catheterisation.
Give 3 bacterial virulence factors that aid their ability to cause UTI’s.
- Fimbriae/pili that adhere to urothelium.
- Acid polysaccharid coat resists phagocytosis.
- Toxins e.g. UPEC releases cytotoxins.
- Enzyme production e.g. urease.
What do type 1 pili bind to?
Uroplakin.
What do type P pili bind to?
Glycolipids on urothelium.
What type of pili would you associate with a lower UTI?
Type 1.
What type of pili would you associate with an upper UTI?
Type P.
The vagina is heavily colonised with lactobacilli. What is the function of this?
Helps maintain a low pH = host defence mechanism.
Give 2 reasons why a post menopausal woman is more susceptible to a UTI.
- pH rises -> increased colonisation by colonic flora.
- Reduced mucus secretion.
Give 5 host defence mechanisms against urinary tract infection.
- Antegrade flushing of urine.
- Tamm-horsfall protein.
- GAG layer.
- Low urine pH.
- Commensal flora.
- Urinary IgA.
What is pyuria?
The presence of leukocytes in urine.
Name 4 lower urinary tract infections.
- Cystitis.
- Prostatitis.
- Epididymitis.
- Urethritis.
Name 1 upper urinary tract infection.
Pyelonephritis.
What investigations might you do on someone who you suspect has a UTI?
- Take a good history.
- Urinalysis - multistix SG.
- Microscopy; culture and sensitivity of mid-stream urine.
- In recurrent/complicated UTI renal imaging is important.
What determines if a UTI is complicated or uncomplicated?
A UTI is deemed complicated if it affects:
- Someone with an abnormal urinary tract.
- A man.
- A pregnant lady.
- Children.
- The immunocompromised.
- If it is recurrent.
What is the first line treatment for an uncomplicated UTI?
- Trimethoprim or nitrofurantoin for 3 days.
- Increased fluid intake and regular voiding.
How does trimethoprim work?
It affects folic acid metabolism.
Describe the management for a complicated UTI.
Same as for an uncomplicated UTI but a MCS MSU is essential! The patient would normally take a longer Abx course tailored to sensitivity.
Give 3 causes of recurrent UTI’s.
- Re-infection.
- Bacterial persistence.
- Unresolved infection.
Define recurrent UTI.
> 2 episodes in 6 months of > 3 in 12 months.
Describe the management for someone who is having recurrent UTI’s.
- Increase fluid intake.
- Regular voiding.
- Void pre and post intercourse.
- Abx prophylaxis.
- Vaginal oestrogen replacement.
What is cystitis?
Inflammation of the bladder secondary to infection.
Give 4 risk factors for cystitis.
- Obstruction.
- Previous damage to bladder epithelium.
- Bladder stones.
- Poor bladder emptying.
Give 3 symptoms of cystitis.
- Dysuria.
- Frequency.
- Urgency.
Describe the NIDDK classification for prostatitis.
- Type 1: acute bacterial prostatitis.
- Type 2: chronic bacterial prostatitis.
- Type 3a: Inflammatory chronic pelvic pain syndrome.
- Type 3b: non-inflammatory chronic pelvic pain syndrome.
- Type 4: asymptomatic inflammatory prostatitis.
Give 5 symptoms of acute bacterial prostatitis (type 1).
- Systemically unwell, fever.
- Rigors.
- Voiding LUTS (straining, hesitancy, incomplete emptying, poor flow).
- Pelvic pain.
Give 4 symptoms of chronic bacterial prostatitis (type 1).
- Recurrent UTI’s.
- Pelvic pain.
- Voiding LUTS (straining, hesitancy, incomplete emptying, poor flow).
- Uropathogens in urine.
The patient should have had the symptoms for >3 months.
Give a symptom of type 3 prostatitis.
Chronic pelvic pain.
What investigations might you do in someone with prostatitis?
- Urinalysis and MSU.
- Semen cultures.
- STI screen.
- Bloods including MCS.
Describe the treatment for type 1 prostatitis.
Type 1 = acute bacterial prostatitis.
- IV Abx e.g. gentamicin, co-amoxiclav for 2-4 weeks.
Describe the treatment for type 2 prostatitis.
Type 2 = chronic bacterial prostatitis.
- 4-6 weeks quinolone e.g. ciprofloxacin.
What can cause urethritis?
STI’s e.g. gonorrhoea, chlamydia.