GMS 6401 FINAL EXAM QUESTIONS & ANSWERS
The kidney consists of specialized vascular and tubular structures (the nephron) which
collaborate in the production of urine: - answers - the glomerular capillary is
surrounded by an epithelial structure which forms the beginning of the tubule
A diagnostic renal clearance experiment is conducted and the following steady state (=
equilibrium) measurements are obtained on a 34 year old male subject, weighing 60 kg
(assume that the renal plasma flow (rpf) is the same as the effective renal plasma flow
(erpf)
Urine inulin = 200 mg/100mlplasma inulin = 4 mg/100ml.urine flow (v) = 2ml/minurine
pah = 1200 mg/100mlplasma pah = 6 mg/100ml - answers - gfr = 100 ml/min
200/4 x 2 ml/min = gfr = 100 ml/min
Erpf = 1200/6 x 2 ml/min = 400 ml/min
Ff= gfr / erpf = 100/400 = 0.25
Any substance which is freely filtered at the glomerulus, is reabsorbed and is not
secreted, will have a renal clearance that is: choose one best answer. - answers - less
than the clearance of inulin
- a fractional clearance (ratio of clearances of substances to inulin) < 1.0 indicates net
tubular reabsorption of freely filtered substances
An increased protein excretion (proteinuria) can indicate glomeruluar damage. Which of
the following changes are likely to cause proteinuria? Choose 1 best answer: - answers
- loss of nephrin from the epithelial slit pore diaphragm
- nephrin is an essential protein & mutations are associated with heavy proteinuria
Maintenance of a high glomerular filtration rate (gfr) is required for optimal kidney
function. Which of the following options would be most likely to associate with a below
optimal gfr in man? - answers - a low glomerular capillary water permeability
A selective increase in renal plasma flow (rpf) due to parallel relaxation of the afferent
and efferent arterioles leads to: - answers - a rise in gfr with no change in filtration
fraction; parallel relaxation of afferent & efferent arterioles allows flow to increase (due
to fall in renal vascular resistance) without a change in glomerular blood pressure or
filtration fraction
An increase in renal blood flow will lead to which of the following changes within the
kidney: - answers - increased total renal oxygen consumption but little change in the
renal venous oxygen content (arterial - venous difference)
- more na filtered so more to reabsorb so total renal oxygen consumption will increase
but because this is matched by the increased rbf, the oxygen extraction (a-v difference)
across the kidney will stay about constant
, In which tubule segment is there active sodium reabsorption by the na/k/2cl (nkcc2)
transporter but never any water resabsorption? - answers - thick ascending limb of the
loop of henle
The release of renin from the kidney, into the circulation is stimulated by - answers - a
fall in renal perfusion pressure is one of the volume depletion signals that stimulate
renin release
An extracellular fluid volume expansion leads to - answers - increased right atrial
pressure - signal to anp release
A reduction in sodium excretion occurs when - answers - septic shock occurs - when
septic shock develops the perceived fall in circulating blood volume leads to excessive
na retention and therefore a fall in na excretion
An increased in renal sympathetic nerve activity will lead to which combination of
changes: - answers - increased renal renin release and a fall in renal plasma flow
- alpha adrenergic fibers stimulate renal arterioles and small arteries to vasoconstrict,
lowering renal plasma flow. Beta adrenergic nerve fibers stimulate renin release from
the granular cells in afferent arteriole
An increase in antiduretic hormone (adh) release will occur when: - answers - plasma
osmolality increases by 2% - when plasma osm increases by greater than 1% above
normal, adh is released
A patient with nephrogenic diabetes insipidus is most likely to present with which
combination of plasma and urine osmolality - answers - high plasma osmolality, low
urine osmolality
- nephrogenic diabetes insipidus means the collecting duct cannot reaborb water, so
urine is dilute and plasma osm increases due to renal water loss
Adh (antidiuretic hormone) stimulates the reabsorption of ___ and ___ in the kidney
collecting ducts of a normal individual. Choose 1 best answer: - answers - water &
urea
Urine concentration will increase when the following events occur: - answers - blood
volume falls by 15%
- when blood volume falls by >10% adh is released in large quanitities. Water is retained
and urine concentration increases
The primary regulation of renal potassium (k) excretion occurs in which segment? -
answers - collecting duct. K is reabsorbed in proximal tubule and talh and usually
secreted in the collecting duct (from the principal cells) unless the body needs to retain
k in which case further reabsorption can occur in the collecting duct (via intercalated
cells type a)
The kidney consists of specialized vascular and tubular structures (the nephron) which
collaborate in the production of urine: - answers - the glomerular capillary is
surrounded by an epithelial structure which forms the beginning of the tubule
A diagnostic renal clearance experiment is conducted and the following steady state (=
equilibrium) measurements are obtained on a 34 year old male subject, weighing 60 kg
(assume that the renal plasma flow (rpf) is the same as the effective renal plasma flow
(erpf)
Urine inulin = 200 mg/100mlplasma inulin = 4 mg/100ml.urine flow (v) = 2ml/minurine
pah = 1200 mg/100mlplasma pah = 6 mg/100ml - answers - gfr = 100 ml/min
200/4 x 2 ml/min = gfr = 100 ml/min
Erpf = 1200/6 x 2 ml/min = 400 ml/min
Ff= gfr / erpf = 100/400 = 0.25
Any substance which is freely filtered at the glomerulus, is reabsorbed and is not
secreted, will have a renal clearance that is: choose one best answer. - answers - less
than the clearance of inulin
- a fractional clearance (ratio of clearances of substances to inulin) < 1.0 indicates net
tubular reabsorption of freely filtered substances
An increased protein excretion (proteinuria) can indicate glomeruluar damage. Which of
the following changes are likely to cause proteinuria? Choose 1 best answer: - answers
- loss of nephrin from the epithelial slit pore diaphragm
- nephrin is an essential protein & mutations are associated with heavy proteinuria
Maintenance of a high glomerular filtration rate (gfr) is required for optimal kidney
function. Which of the following options would be most likely to associate with a below
optimal gfr in man? - answers - a low glomerular capillary water permeability
A selective increase in renal plasma flow (rpf) due to parallel relaxation of the afferent
and efferent arterioles leads to: - answers - a rise in gfr with no change in filtration
fraction; parallel relaxation of afferent & efferent arterioles allows flow to increase (due
to fall in renal vascular resistance) without a change in glomerular blood pressure or
filtration fraction
An increase in renal blood flow will lead to which of the following changes within the
kidney: - answers - increased total renal oxygen consumption but little change in the
renal venous oxygen content (arterial - venous difference)
- more na filtered so more to reabsorb so total renal oxygen consumption will increase
but because this is matched by the increased rbf, the oxygen extraction (a-v difference)
across the kidney will stay about constant
, In which tubule segment is there active sodium reabsorption by the na/k/2cl (nkcc2)
transporter but never any water resabsorption? - answers - thick ascending limb of the
loop of henle
The release of renin from the kidney, into the circulation is stimulated by - answers - a
fall in renal perfusion pressure is one of the volume depletion signals that stimulate
renin release
An extracellular fluid volume expansion leads to - answers - increased right atrial
pressure - signal to anp release
A reduction in sodium excretion occurs when - answers - septic shock occurs - when
septic shock develops the perceived fall in circulating blood volume leads to excessive
na retention and therefore a fall in na excretion
An increased in renal sympathetic nerve activity will lead to which combination of
changes: - answers - increased renal renin release and a fall in renal plasma flow
- alpha adrenergic fibers stimulate renal arterioles and small arteries to vasoconstrict,
lowering renal plasma flow. Beta adrenergic nerve fibers stimulate renin release from
the granular cells in afferent arteriole
An increase in antiduretic hormone (adh) release will occur when: - answers - plasma
osmolality increases by 2% - when plasma osm increases by greater than 1% above
normal, adh is released
A patient with nephrogenic diabetes insipidus is most likely to present with which
combination of plasma and urine osmolality - answers - high plasma osmolality, low
urine osmolality
- nephrogenic diabetes insipidus means the collecting duct cannot reaborb water, so
urine is dilute and plasma osm increases due to renal water loss
Adh (antidiuretic hormone) stimulates the reabsorption of ___ and ___ in the kidney
collecting ducts of a normal individual. Choose 1 best answer: - answers - water &
urea
Urine concentration will increase when the following events occur: - answers - blood
volume falls by 15%
- when blood volume falls by >10% adh is released in large quanitities. Water is retained
and urine concentration increases
The primary regulation of renal potassium (k) excretion occurs in which segment? -
answers - collecting duct. K is reabsorbed in proximal tubule and talh and usually
secreted in the collecting duct (from the principal cells) unless the body needs to retain
k in which case further reabsorption can occur in the collecting duct (via intercalated
cells type a)
