Chapter 17
________ are composed of crystals and proteins that grow until they break loose and pass into the urine collection system.
Renal calcul
Renal clearance is decreased by reabsorption and increased by secretion.
TRUE
In response to low blood plasma Na+, reduced ADH will decrease water volume in the blood to match lower Na+ concentration while increased aldosterone will increase Na+ reabsorption to match the higher water volume of blood.
True
Inulin clearance gives a measurement of the glomerular filtration rate.
True
Inulin is a good measure of GFR because it is filtered but neither reabsorbed nor secreted by the kidneys.
True
Macula densa cells of the juxtaglomerular apparatus are part of the tubuloglomerular feedback mechanism.
True
Only about 20% of renal blood is filtered in one pass through the kidneys.
True
Plasma measurement of creatinine is a close estimate of GFR.
True
Salt leaving the ascending limb of the loop of Henle causes the loss of water from the descending limb of the loop of Henle.
True
Since water follows the reabsorption of Na+ in the proximal tubule, the filtrate is isomotic with the blood.
True
The apical membranes of the tubular cells are impermeable to bicarbonate.
True
The buffers of urinary pH are ammonia and monohydrogen phosphate.
True
The collecting duct is naturally impermeable to salt but permeable to water.
True
The guarding reflex prevents voiding.
True
The presence of antidiuretic hormone causes aquaporins to be formed in the collecting duct cells.
True
The proximal convoluted tubule reabsorbs approximately 65% of water and ions salt entering it.
True
The renal plasma clearance of a substance that is filtered and reabsorbed must be less than the GFR.
True
The vasa recta have the net effect of concentrating solutes in the interstitial fluid of the renal medulla.
True
Tubular secretion of small xenobioticsis often accomplished by polyspecific organic anion transporters.
True
Urine collects in the urinary bladder prior to entry into the urethra.
True
Water permeability in the collecting duct is varied by altering the number of aquaporins present.
True
_________ is a nonsalt molecule that contributes to the hypertonicity of the interstitial fluid of the renal tubules.
Urea
Neurohypophyseal secretion of __________ stimulates formation of concentrated urine.
antidiuretic hormone
What is present in the vasa recta to remove water for the interstitial fluid of the renal medulla?
aquaporins
What is the order that filtrate must pass through to the glomerular capsule?
capillary fenestrae, glomerular basement membrane, podocytes of visceral glomerular epithelium
Bicarbonate must be converted to ____ to move into tubule cells to reduce blood pH.
carbon dioxide
Inhibiting the actions of __________ would impair the ability of the kidney to regulate pH of the blood.
carbonic anhydrase
Through renal autoregulation, an increase in blood pressure will cause the afferent arteriole to ____ and therefore the GFR will ____.
constrict, not change
The renal plasma clearance of a substance that is filtered but not reabsorbed or secreted is ___ the GFR.
equal to
The main region of aldosterone action is the
cortical collecting duct.
Decreased glomerular filtration rate would
decrease plasma creatinine clearance rate.
Aldosterone secretion from the adrenal cortex is stimulated by a(n) ____ in blood Na+ or a(n) ___ in blood K+.
decrease, increase
Glomerular filtration would be decreased by
decreased glomerular hydrostatic pressure.
Excessive aldosterone secretion would induce
decreased plasma potassium.
Inhibition of the functions of the descending limb of the loop of Henle would stimulate
decreased water reabsorption.
The ____ limb of the loop of Henle is impermeable to salt
descending
Na+ moves by _____ from the filtrate into the epithelial cells of the proximal tubule.
diffusion
Hypotension would induce __________ of afferent arterioles.
dilation
Tubular ultrafiltrate enters the collecting duct from the
distal convoluted tubule
Renal clearance of PAH __________ glomerular filtration rate.
exceeds
Which sphincter is under voluntary control?
external urethral sphincter
Which of the following is a layer of the renal corpuscle?
glomerular visceral epithelium glomerular parietal epithelium glomerular endothelium D. All of the choices are correct.
The __________ is a capillary network that produces a blood filtrate that enters the urinary tubules.
glomerulus
What structure is an arteriole capillary bed - drained by an arteriole instead of a venule?
glomerulus
Since most filtered bicarbonate is reabsorbed, where does the bicarbonate come from that is used to compensate for acidosis?
glutamine
The renal plasma clearance of a substance that is filtered and secreted is ____ the GFR.
greater than
The presence of renin secreting tumors may cause
hypertension. B. increased aldosterone secretion. C. increased renal sodium reabsorption. D. All of the choices are correct.
An increase in extracellular H+ concentration may result in ______ extracellular K+.
increased
An inadequate dietary intake of NaCl will cause
increased renin secretion.
Hemorrhage would induce
increased renin secretion.
The guarding reflex allows the urinary bladder to fill by
inhibiting parasympathetic stimulation of the detrusor muscle. B. stimulating sympathetic nerves to the external urethral sphincter to contract. C. responding to stretch receptors in the bladder wall. D. All of the choices are correct.
The _______________ nephrons play an important role in producing concentrated urine.
juxtamedullary
Angiotensin-converting enzyme is mostly present in the capillaries of the
lungs
The conversion of angiotensin I into angiotensin II occurs primarily in the
lungs
The sensor in tubuloglomerular feedback is a group of cells called the
macula densa.
The renal pelvis receives urine from the
major calyces
Depletion of extracellular K+ may induce
metabolic alkalosis.
The process of urination is called
micturition
The __________ is the functional unit of the kidney
nephron
The minimum urine volume needed to excrete metabolic wastes produced by the body is called as
obligatory water loss.
Diuretics
often act on the distal convoluted tubule.
Which transporters in the proximal tubule are polyspecific and transport small molecules of drugs and toxins to the ultrafiltrate?
organic anion transporters
Damage to which of the following neurons would impair micturition?
parasympathetic neurons sympathetic neurons pudendal somatic motor neurons D. All of the choices are correct.
Which of the following is NOT a potential filtration barrier in the glomerular capsule?
parietal layer of the capsule
Urea transport in the collecting duct is a(n) __________ process.
passive
The efferent arteriole delivers blood to the
peritubular capillaries
What type of cells form the third filtration barrier?
podocytes
Where is the micturition center?
pons
Incontinence could develop as a result of
pressure on the detrusor muscle. B. poor bladder compliance. C. damage to the external urethral sphincter. D. All of the choices are correct
The effectiveness of some antibiotics, such as penicillin, is enhanced by preventing their excretion by use of
probenecid
The majority of reabsorption occurs in the
proximal convoluted tubule.
The return of molecules from the tubules to the blood is called as
reabsorption
The ability of the kidneys to maintain a relatively constant GFR despite fluctuating blood pressures is called as
renal autoregulation
Shock-wave lithotripsy is used to treat
renal calculi
The ability of the kidneys to remove molecules from the blood plasma by excreting them in the urine is known as
renal clearance
The minimum plasma concentration of a substance that results in the excretion of that substance in the urine is the
renal plasma threshold.
Granular cells of the juxtaglomerular apparatus respond to decreased blood volume and increased sympathetic nerve activity by secreting
renin
The movement of molecules and ions from the peritubular capillaries into interstitial fluid and then into the nephron tubule is called
secretion
The primary filter to exclude proteins from the filtrate is the
slit diaphragm
Due to the action of aldosterone, water is reabsorbed because
sodium is reabsorbed into peritubular blood.
Antidiuretic hormone
stimulates water reabsorption by the kidney. B. induces fusion of aquaporin containing vesicles with the plasma membrane. C. is secreted in response to dehydration. D. All of the choices are correct.
Changes in blood volume are detected by
stretch receptors in the atria.
What is the net filtration pressure of the glomerular capillaries?
10 mm Hg outward
If the rate of urine formation is 2 ml/min, the urine inulin concentration is 25 mg/ml, and the plasma inulin concentration
100 mL/min
The average glomerular filtration rate is equal to
180 L/day.
The obligatory water loss needed to excrete metabolic wastes is _____ per day.
400 mL
Which of the following is the correct order of the nephron tubule structures?
Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule
The tubular filtrate osmolarity __________ as it flows through the ascending limb of the loop of Henle.
Decrease
A decrease in blood pressure will cause an increase in GFR through sympathetic stimulation.
False
ATP and adenosine from macula densa cells stimulate vasodilation of the afferent arteriole.
False
An increase of blood volume will cause secretion of ADH.
False
Damage to the lumbar region of the spinal cord could impair micturition
False
Diabetes mellitus is a disease associated with the inadequate secretion or action of ADH.
False
Increased aldosterone secretion stimulates renal potassium retention.
False
Na+ is actively transported into the tubule cells of the ascending limb of the Loop of Henle from the tubular lumen
False
Potassium secretion by the kidneys is only possible due to the action of aldosterone.
False
The concentration of glucose in the glomerular ultrafiltrate is less than that of plasma.
False
The kidneys can directly reabsorb bicarbonate.
False
The kidneys provide short term adjustments to maintain body pH.
False
The main function of the kidneys is the regulation of the intracellular fluid.
False
The maximal response to antidiuretic hormone occurs in the cortical nephrons.
False
The osmotic diuretic mannitol inhibits salt and water absorption in the proximal convoluted tubule.
False
The proximal tubule and loop of Henle are subject to hormonal regulation of sodium and water.
False
The transport of water is always an active process.
False
Under conditions of severe dehydration approximately 99.2% of the glomerular ultrafiltrate volume is reabsorbed.
False
Urea is transported out of the descending limb of the loop of Henle to add to the high osmolarity of the medulla
False
Water permeability of the proximal convoluted tubule is regulated by antidiuretic hormone
False
What creates a Na+ concentration gradient in the proximal tubule?
Na+/K+ pump
_______________ is an autosomal dominant inherited condition in which progressive renal failure develops due to expanded portions of the renal tubule.
Polycystic kidney disease
People with diabetes mellitus have polyuria because
they have greater oncotic pressure in the kidney tubules.
PAH actually measures
total renal blood flow.
The _________________ is the saturation point of renal carrier molecules.
transport maximum
What structures carry urine from the kidneys to the urinary bladder?
ureters
The __________ acts as a countercurrent exchanger.
vasa recta
Increased sympathetic neuron activity will cause
vasoconstriction of afferent arterioles.
Conn's syndrome results in hypokalemia and
Both metabolic alkalosis and loss of H+ are correct.
Countercurrent multiplication occurs by the actions of the
Both vasa recta and loop of Henle are correct.
Antidiuretic hormone exerts its effect via a cAMP second messenger system.
True
As the tubular filtrate moves through the descending limb of the loop of Henle, the osmolality of the filtrate increases.
True
Blood pressure is regulated through the actions of the kidneys.
True
Dilation of the afferent arteriole would increase glomerular pressure.
True
Diuresis is stimulated by atrial natriuretic peptide
True
Epithelial cells of the proximal tubule have a lower concentration of Na+ than the filtrate.
True
Highly elevated blood pressure would stimulate an increased glomerular filtration rate.
True
The __________ limb of the loop of Henle is impermeable to water.
Ascending
The __________ surface of the simple cuboidal epithelia in the proximal convoluted tubule contains microvilli.
Basal
The reabsorption of Na+ in the proximal tubule creates an osmotic gradient for the diffusion of _____ to occur.
H2O
An increase in plasma osmolality will cause the secretion of ADH.
True
An increased GFR leads to an increase in urine production.
True
Na+ reabsorption is a(n) __________ process, while Cl- reabsoprtion is a(n) __________ process.
active, passive
Inhibition of __________ secretion from the adrenal cortex stimulates hyperkalemia.
aldosterone
The concentration of renal filtrate is highest in the
base of the Loop of Henle.
Where are OATs located?
basolateral membrane of proximal tubule cells
The actions of the kidney include regulation of
blood plasma pH. blood plasma volume. blood plasma electrolyte concentration. D. All of the choices are correct.
In response to alkalosis
the kidney excretes bicarbonate.
People with diabetes mellitus have glycosuria because
the plasma glucose concentration is greater than the renal plasma threshold.
