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.