What is the maximum molecular weight of a molecule able to be filtered by the glomerulus?
a) 2,000 Da
b) 7,000 Da
c) 35,000 Da
d) 70,000 Da
d) 70,000 Da ??
The primary goal of renal autoregulation of blood flow is to:
a) Maintain GFR
b) Maintain blood supply to renal medulla
a) maintain GFR
- In actual fact, the renal medulla and its metabolic requirements have no control over the renal autoregulation
Plasma creatinine can be used as a measure of GFR:
A) can be used to calculate creatinine clearance
- creatinine is freely filtereted, not reabsorbed BUT IT IS SECRETED
Creatinine/urea is not used for the measurement of GFR because?
a) it is not readily filtered
b) it is secreted in the ascending loop of Henle
c) it is reaborbed in the proximal tubule
d) ?
??b) it is secreted in the ascending loop of henle?
Unsure of answer because creatinine IS used to measure GFR.
Urea is absorbed in the PCT 50%, it is also secreted a small amount in the ascending loop of henle
What is Glomerular capillary hydrostatic pressure?
a) 20 mmHg
b) 30 mmHg
c) 40 mmHg
d) 50 mmHg
e) 60 mmHg
e) 60 mmHg
Aldosterone
a) increases Na, K & H20 reabsorption
b) increases Na & H20 reabsorption
c) ?
d) ?
b) increases Na & H20 reabsorption
The following is associated with a decrease in renin secretion?
a) vasopressin
b) angiotensin
c) oxytocin II
d) SNS activity on kidney
Renin secretion inhibited by:
1. Angiotensin II
2. increased afferent arteriolar BP
3. ADH (Vasopressin)
4. Increased Cl- at macular densa
ie. answer is either a) vasopressin or
b) angiotensin II
Why can't urea be used to measure GFR?
a) it is actively reabsorbed in PCT
b) it is actively secreted in LoH
c) its concentration (didn't say where) is under control of ADH
Urea is both reabsorbed in PCT (50%) and ?? maybe secreted in LoH
more likely answer is:
a) it is actively reabsorbed in PCT
Tubuloglomerular balance means:
a) proportionate reabsorption of filtered load
b) osmolality of filtrate and plasma is the same
c) the proportionate urine output relative to GFR
d) the maintenance of equal Na+ concentration in glomerular filtrate and proximal tubule
e) none of the above
a) proportionate reabsorption of filtered load
Renal oxygen consumption:
a) best correlates with Na/K ATPase activity
b) is greater than the ?? heart
c)
d)
e)
a) best correlates with Na/K ATPase activity
Glycosuria is most likely to occur if:
a) both GFR and plasma glucose level increase
b) GFR increase but plasma glucose remains same
c) plasma glucose increased but GFR remains smae
d) both GFR and plasma glucose decrease
e)
a) both GFR and plasma glucose level increase
Which one of the following increase tubular reabsorption of salt and water?
a)
b)
c) increase oncotic pressure of peritubular capillaries
d) increase hydrostatic pressure of peritubular capillaries
c) increase oncotic pressure of peritubular capillaries
Response to significant hypovolaemia and decreased plasma osmolality
a) increased urine output
b) decreased urine output
b) decreased urine output
Renal circulation
a)
b) renal O2 consumption is higher than cardiac by mls/100g/min
c) renal circulation has the highest resistance in the body
d) renal medulla has higher oxygen supply than cortex
e) renal oxygen consumption is proportional to sodium transport
e) renal oxygen consumption is proportional to sodium transport
Osmotic diuresis
a) causes sodium loss
b) washes out medullary concentration gradient
c) increases afferent arteriole pressure
d) increases blood flow to the cortex
e) all of the above
unsure
The ascending limb of the loop of Henle
a) is permeable to water
b) active transport of K+ into the lumen
c) active transport of water into the lumen
d) active transport of Cl- out of the lumen
e) active transport of Na+ into the lumen
d) active transport of Cl- out of the lumen
Maximal urine pH?
a) 3.0
b) 3.5
c) 4.0
d) 4.5
e) 5.0
d) 4.5
Renal oxygen consumption
a) is greated in the medulla than the cortex
b)
c) is greater than the brain per unit weight
d)
e) is 25ml/100g/min (whatever the correct units were)
Both A and C are correct. Reference for A - Ganong Ed 21 pp708
and for C pp615
Which is an action of aldosterone on principal cells?
a) K reabsorption
b) H secretion
c) Na reabsorption
d) bicarb secretion
e) Cl reabsorption
Aldosterone causes K secretion and Na absorption from principal cells
Also H secretion from intercalated cells
is answer is c) Na reabsorption
Regarding the renal effects of intermittent positive pressure ventilation?
a) Na retention due to increased ANP release
b) decreased cardiac output causes oliguria
c) ?? increased venous pressure and ?? inc/dec in renal blood flow
IPPV leads to:
- dec renal water and sodium excretion
- stim low P receptors --> ADH secretion
- dec preload means dec ANP = inc Na reabs and water reabs
so A) is incorrect
? correct answer b) decreased CO causes oliguria
Juxtamedullary nephrons
a) have long loops of henle
b) have no glomeruli in the cortex
a) have long loops of
henle
Increased tubular reabsorption with increased GFR is related to:
a) glomerulotubular balance
b) autoregulation
c) tubuloglomerular balance
d) tubuloglomerular feedback
Glomerulotubular balance - is the balance between reabsorption of solutes in the proximal renal tubules and GFR
tubuloglomerular balance - ?
tubuloglomerular feedback - TG feedback is a negative feedback loop controlled by the juxtaglomerular apparatus that serves to maintain filtrate flow at a constant rate.
a) glomerulotubular balance
Which of the following results in decreased K excretion?
a) prolonged vomitting
b) metabolic acidosis
c) normal saline infusion
d) aldosterone
e) renal failure
e) renal failure
aldosterone (mineralocorticoid) increased aldost increases K excretion
Which of the following scenarios is most likely to result in glycosuria?
a) increased GFR and increased BSL
b) Decreased GFR and Increased BSL
c) various combinations of GFR/BSL increase and decrease
??
Renal handling of Urea?
a) urea is produced in kidneys
b) Converted to ammonium by liver
c)
d) 20% of filtered urea is excreted in urine
e)
d) 20% of filtered urea is excreted in urine
Regarding urea
a) synthesised via urea cycle to produce 3 ATP molecules
b) synthesised from ammonia ( or was it ammonium?)
Creatinine is used to measure GFR because
a) plasma levels corresponds to loss of nephrons
b) it is freely filtered, not secreted not reabsorbed
c) levels start to rise when GFR decrease by 15%
d) it has a relatively constant level in plasma due to liver metabolism
e) used to calculate creatinine clearance