Genitourinary Lectures Flashcards
Define glomerular filtrate rate.
Fluid volume filtered through glomeruli per time unit.
List 3 normal GFRs.
1) 120ml/min
2) 7200ml/hr
3) 170L/day
What percentage of cardiac output do the kidneys receive?
20%.
What does eGFR predict?
Creatinine generation.
List 3 factors that affect eGFR.
1) age
2) gender
3) race
List the 3 sites for sodium reabsorption.
1) PCT - 70%
2) loop of Henle - 25%
3) DCT - 5%
What part of the kidney is most vulnerable to damage and what type?
PCT, ischaemic injury.
What transporters are found in the loop of Henle?
Na2KCl cotransporters.
Where do loop diuretics work?
Thick ascending limb of loop of Henle.
Where do thiazide diuretics work?
DCT.
What is the juxtaglomerular apparatus? (2)
1) organ that senses solute concentration
2) release renin when GFR is low
What is aldosterone’s function? (3)
1) increased eNac channel in collecting duct
2) sodium reabsorbed
3) potassium excreted
Where is potassium mostly reabsorbed? (2)
1) PCT
2) loop of Henle
List 2 hormones that increase potassium reabsorption.
1) insulin
2) catecholamines (e.g. DA, NA, A)
List 2 medications that cause hypokalaemia.
1) loop diuretics
2) thiazide diuretics
List 5 medications that cause hyperkalaemia.
1) spironolactone (aldosterone antagonist)
2) ACEi
3) ARB
4) amiloride (acts on eNac, i.e. collecting duct)
5) trimethoprim (acts on eNac, i.e. collecting duct)
Where is water concentration detected?
Hypothalamus.
Describe erythropoietin.
Hormone produced by kidneys in response to tissue hypoxia. Increases haemoglobin production.
What is MAP.
Mean arterial pressure, 60-70mmHg
Describe the change in glomerular filtrate pressure along the nephron. (2)
1) 60-70mmHg at Bowman’s capsule (MAP)
2) 3-10mmHg at collecting duct
What spinal nerve roots control urinating.
S3-S5 (PNS).
What spinal nerve roots control urine storage.
T10-L2 (SNS).
What is the volume of the bladder?
500ml.
What epithelium is found in the bladder?
Urothelium - transitional epithelium, 3-7 cells thick, completely impermeable.
What gender is more likely to develop retention?
Male, longer urethra so greater voiding pressure required.
What gender is more likely to develop incontinence?
Female, shorter urethra, lower voiding pressure to overcome.
List 3 common narrowings where renal calculi occur.
1) pelviureteric junction
2) pelvic brim
3) vesicoureteric junction
Define hydronephrosis.
Urine filled dilation of renal pelvis as ureter is blocked.
What are infection induced renal calculi composed of? (3)
Struvite (magnesium ammonium phosphate, NH₄MgPO₄·6H₂O).
What is the difference between nephrolithiasis, renal calculi and renal colic? (3)
1) nephrolithiasis - formation of kidney stones
2) renal calculi - kidney stones
3) renal colic - pain due to kidney stones
Define stranguria.
Burning dysuria in frequent small volumes despite urgency (i.e. inc. dysuria, oliguria, urgency)
What is another name for acute kidney injury?
Acute renal failure.
What is AKI characterised by? (2)
1) high serum urea creatinine
2) low urine output
i.e. decreased GFR
What percentage of hospital patients have AKI?
18%.
What percentage of ITU patients have AKI?
50%
List 5 types of renal replacement therapy.
1) haemodialysis
2) peritoneal dialysis
3) haemofiltration
4) haemodiafiltration
5) kidney transplant
List indications for dialysis.
1) symptomatic uraemia (e.g. pericarditis)
2) uncontrolled hyperkalaemia
3) metabolic acidosis
4) fluid overload
List 3 complications of renal replacement therapy.
1) CVD (e.g. MI)
2) infection
3) amyloidosis
Define hepatorenal syndrome.
AKI in patients with cirrhosis or fulminant liver failure.
List 4 types of kidney cancer.
1) renal cell carcinoma (85%)
2) transitional cell carcinoma (10%)
3) sarcoma
4) nephroblastoma (Wilms’ tumour)
What percentage of renal cell carcinoma present with metastasis?
25%.
What age group does Wilms’ tumour affect?
0-3 years old.
What percentage of transitional cell carcinomas occur in the bladder?
50%.
List 4 organs lined by transitional epithelium.
1) kidney (renal calyces, renal pelvis)
2) ureter
3) bladder
4) urethra
What should any patient over 40 years old with haematuria be assumed to have?
Transitional cell carcinoma (bladder).
What’s the most common cancer in 15-44 year old males?
Testicular cancer.
What is the most common male cancer?
Prostate cancer.
What percentage of PSAs are normal in cancer patients?
30%.
What score is used to diagnose prostate cancer using a transrectal ultrasound guided prostate biopsy?
Gleason score.
What is the treatment of prostate cancer dependent on?
The projected survival of the patient, i.e. more years likely to live more likely to carry out a radical prostatectomy.
List 4 storage lower urinary tract symptoms (LUTS).
1) nocturnal
2) frequency
3) urgency
4) incontinence
List 6 voiding lower urinary tract symptoms.
1) hesitancy
2) poor intermittent stream
3) straining
4) dysuria
5) haematuria
6) after dribble (post micturition or terminal)
Define post micturition dribble.
Involuntary loss of urine a few minutes after passing urine (often after leaving toilet).
Define terminal dribble.
Difficulty in stopping passing urine.
What is protective against benign prostatic hyperplasia?
Castration.
List 3 things not caused by benign prostatic hyperplasia.
1) infertility
2) erectile dysfunction
3) prostate cancer
How do α1 blockers treat benign prostatic hyperplasia?
Smooth muscle relaxation in bladder neck and prostate decreases obstructive LUTS.
When should α1 blockers not be prescribed?
Postural hypertension.
What is the function of 5α reductase?
Testosterone —> dihydrotestosterone (active form).
How do 5α reductase inhibitors treat benign prostatic hyperplasia? (2)
1) block conversion of testosterone to dihydrotestosterone
2) prevents prostatic growth
What are the complications of transurethral resections of prostate (TURPs)? (3)
1) impotence (14%)
2) erectile dysfunction (10%)
3) incontinence (1%)
List 2 things find in UTI urine.
1) bacteria (bacteriuria)
2) pus (pyuria)
List 5 pathogens that cause UTIs in primary settings.
1) Klebsiella
2) Enterococci
3) Escherichia coli
4) Proteus
5) Staphylococci
In what setting is there a broader range of UTI causes?
Hospital.
Define uncomplicated UTI.
UTI in healthy non-pregnant woman with normally functioning urinary tract.
Define complicated UTI.
UTI in patients with abnormal urinary tract (e.g. stones) or systemic disease involving kidneys (e.g. diabetes mellitus).
What is the likelihood of a woman getting a UTI in her lifetime?
1/3.
List 3 virulence factors that increase uropathogenic Escherichia coli’s virulence in UTIs.
1) P pilli - urethral ascent
2) aerobactin - iron intake
3) haemolysin - pore formation
What often precedes pyelonephritis?
Cystitis.
What is the common presentation triad of pyelonephritis? (3)
1) loin pain
2) fever
3) pyuria
What is the most common male UTI?
Prostatis.
When does prostatis usually present?
<35 years old.
What is urethritis primarily?
STI.
What is the first test for urethritis (STI)?
Nucleic acid amplification test (NAAT).
What is the most common STI?
Chlamydia.
What is more common in men chlamydia or gonorrhoea?
Gonorrhoea.
What is more common in women chlamydia or gonorrhoea?
Chlamydia.
How does chlamydia gram stain?
Negative.
How does gonorrhoea gram stain?
Negative.
Define epididymo-orchitis.
Inflammation of epididymis and testis.
List 2 causes of epididymo-orchitis.
1) STI (<35 years old)
2) UTI (>35 years old)
List 4 histological changes found in diabetes mellitus caused chronic kidney disease.
1) mesangial expansion and proliferation
2) podocytopathy
3) glomerular basement thickening
4) glomerulosclerosis
What is the ‘best’ form of renal replacement therapy?
Kidney transplant.
What is the most commonly used RRT?
Haemofiltration.
Describe how haemofiltration works. (4)
1) dual lumen catheter placed in vein (jugular, subclavian, femoral)
2) blood pump draws/returns blood from/to lumen
3) ultrafiltrate continuously removed
4) replacement infusion continuously infused
Describe how haemodialysis works.
1) atrioventricular fistula draws/returns blood into a vein
2) blood passed over semi-permeable membrane with counter current dialysis fluid
List 3 disadvantages of haemodialysis.
1) time consuming (3 times a week for 4 hours)
2) large solutes not cleared
3) requires haemodynamically stable unatherosclerotic patient
List 6 complications of haemodialysis.
1) hypotension
2) chest pain
3) infection (dialysis catheter)
4) nausea
5) headaches
6) fever/rigours
What is the main form of RTT used in CKD?
Peritoneal dialysis.
Describe how peritoneal dialysis works.
Peritoneum used as a membrane for fluid and solute exchange.
List 4 complications of peritoneal dialysis.
1) infection (e.g. peritonitis)
2) abdominal hernia
3) bowel perforation
4) loss of peritoneum membrane function (over time)
How much protein is lost via urine in nephrotic syndrome?
> 3.5g/day.
Why is there a hypercoagulable state in nephrotic syndrome?
Loss of antithrombin III.
List 3 features of erection.
1) carvernosal smooth muscle relaxation
2) increased sinusoidal blood flow
3) occlusion of venous outflow
What initiates and maintains erections?
Nitric oxide.
What spinal nerve roots control erections?
S2-S4 (PNS).
What spinal nerve roots control ejaculation?
T11-L2 (SNS).
How is a flaccid state maintained?
Constant sympathetic tone.
List the 3 triggers of erection.
1) psychogenic (sensory stimulation)
2) reflexogenic (genital stimulation)
3) nocturnal (REM sleep)
Describe how an erection forms. (6)
1) S2-S4 pudendal nerve stimulation
2) NO release
3) GTP —> cGMP (guanylate cyclase)
4) protein kinase G closes L-type Ca2+ channels
5) fall in cytoplasmic Ca2+
6) smooth muscle relaxation
What percentage of 40 year olds have erectile dysfunction?
2%.
What percentage of 65 year olds have erectile dysfunction?
25%.
What percentage of patients with radical prostatectomy have erectile dysfunction?
80%.
List 4 side effects of phosphodiesterase-5 inhibitors.
1) headaches
2) flushing
3) dyspepsia
4) runny nose
How do phosphodiesterase-5 inhibitors treat erectile dysfunction? (2)
1) inhibit breakdown of cGMP
2) prolonged smooth muscle relaxation
What percentage of end stage renal failure is caused by glomerulonephritis?
25%.
Define glomerulonephritis.
Broad term of inflammation of glomeruli and nephrons.
List 4 ways glomerulonephritis can present.
1) nephritic syndrome
2) nephrotic syndrome
3) acute kidney injury
4) chronic kidney disease
List 4 things glomerulonephritis can cause.
1) haematuria
2) proteinuria
3) compensatory hypertension
4) acute kidney injury
When do epididymal cysts generally develop?
Around 40 years old.
What side is more commonly affected in varicocele?
Left side, due to the angle left testicular vein enters left renal vein.
