GMS 6401 ANSWERS AND QUESTIONS SET A+
✔✔A selective increase in renal plasma flow (RPF) due to parallel relaxation of the
afferent and efferent arterioles leads to: - ✔✔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: - ✔✔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? - ✔✔thick ascending limb of
the loop of Henle
✔✔the release of renin from the kidney, into the circulation is stimulated by - ✔✔a fall in
renal perfusion pressure is one of the volume depletion signals that stimulate renin
release
✔✔an extracellular fluid volume expansion leads to - ✔✔increased right atrial pressure -
signal to ANP release
✔✔a reduction in sodium excretion occurs when - ✔✔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: - ✔✔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: - ✔✔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 - ✔✔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: - ✔✔water & urea
✔✔urine concentration will increase when the following events occur: - ✔✔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? -
✔✔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 plays a role in maintaining calcium and phosphate balance in the body.
choose 1 best answer: - ✔✔activation of Vitamin D to calcitriol occurs in the kidney and
promotes urinary phosphate reabsorption. the terminal hydroxylation step which
activates Vitamin D to 1-25 dihydroxy vitamin D (Calcitriol) takes place in the kidney,
and calcitriol decreases tubular phosphate excretion
✔✔in the kidney the long term maintenance of acid base balance is due to the renal
excretion of H+ and replenishing of the bodies buffer stones. renal hydrogen ion
excretion has the following characteristics: - ✔✔hydrogen ion secretion in the proximal
tubules is responsible for most of the reabsorption of the filtered HCO3; this is
converted to H20 and CO2. the Co2 diffuses into the cell and is re-formed to create H+
and HCO3 (which is reabsorbed)
✔✔in a normal person, a fall in plasma pH leads to: - ✔✔A rapid increase in H+ uptake
by all the body buffer systems. - all bodies buffers particpate in buffering H+
✔✔A selective increase in renal plasma flow (RPF) due to parallel relaxation of the
afferent and efferent arterioles leads to: - ✔✔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: - ✔✔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? - ✔✔thick ascending limb of
the loop of Henle
✔✔the release of renin from the kidney, into the circulation is stimulated by - ✔✔a fall in
renal perfusion pressure is one of the volume depletion signals that stimulate renin
release
✔✔an extracellular fluid volume expansion leads to - ✔✔increased right atrial pressure -
signal to ANP release
✔✔a reduction in sodium excretion occurs when - ✔✔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: - ✔✔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: - ✔✔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 - ✔✔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: - ✔✔water & urea
✔✔urine concentration will increase when the following events occur: - ✔✔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? -
✔✔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 plays a role in maintaining calcium and phosphate balance in the body.
choose 1 best answer: - ✔✔activation of Vitamin D to calcitriol occurs in the kidney and
promotes urinary phosphate reabsorption. the terminal hydroxylation step which
activates Vitamin D to 1-25 dihydroxy vitamin D (Calcitriol) takes place in the kidney,
and calcitriol decreases tubular phosphate excretion
✔✔in the kidney the long term maintenance of acid base balance is due to the renal
excretion of H+ and replenishing of the bodies buffer stones. renal hydrogen ion
excretion has the following characteristics: - ✔✔hydrogen ion secretion in the proximal
tubules is responsible for most of the reabsorption of the filtered HCO3; this is
converted to H20 and CO2. the Co2 diffuses into the cell and is re-formed to create H+
and HCO3 (which is reabsorbed)
✔✔in a normal person, a fall in plasma pH leads to: - ✔✔A rapid increase in H+ uptake
by all the body buffer systems. - all bodies buffers particpate in buffering H+
