Deck 18: The Urinary System: Renal Function

Question 1

The clearance of what substance, a natural by- product of muscle metabolism, provides a non- invasive estimate of glomerular filtration rate?

A)urea
B)PAH
C)inulin
D)glucose
E)creatinine

Answer 1

E

Question 2

Which of the following is NOT an accurate description of differences between epithelial cells of the proximal and distal tubules?

A)fewer mitochondria in the epithelial cells of the distal tubule
B)greater paracellular transport in the epithelial cells of the distal tubule
C)less prominent microvilli in the epithelial cells of the distal tubule
D)less permeable tight junctions between the epithelial cells of the distal tubule
E)receptors for hormones on the epithelial cells of the distal tubule

Answer 2

B

Question 3

Which of the following equations for determining clearance is correct?

A)clearance = (urine concentration × urine flow rate)/ plasma concentration
B)clearance = GRF × urine concentration
C)clearance = urine concentration (plasma concentration × urine flow rate)
D)clearance = (plasma concentration × urine flow rate)/ urine concentration
E)clearance = plasma concentration / (urine concentration × urine flow rate)

Answer 3

A

Question 4

Which of the forces across the glomerular capillaries tends to increase from the afferent to the efferent arteriole ends?

A)Bowman's capsule oncotic pressure
B)glomerular filtration pressure
C)glomerular oncotic pressure
D)Bowman's capsule hydrostatic pressure
E)glomerular capillary hydrostatic pressure

Question 5

Which layer of the filtration barrier in Bowman's capsule is the primary barrier to the movement of protein from the capillary?

A)epithelial cell
B)basement membrane
C)endothelial cell
D)macula densa
E)granular cell

Question 6

When the solute concentration is high enough in the lumen of the renal tubules such that all of the carrier proteins or pumps for that solute are occupied, the system is operating at

A)tubular threshold.
B)tubular maximum.
C)transport maximum.
D)diffusional saturation.
E)renal threshold.

Question 7

Substances can enter the renal tubules by what renal processes?

A)filtration only
B)reabsorption only
C)secretion only
D)both filtration and secretion
E)both reabsorption and secretion

Question 8

If a substance is neither reabsorbed nor secreted, then its excretion rate is equal to the

A)filtered load.
B)plasma concentration of the substance.
C)renal threshold.
D)glomerular filtration rate.

Question 9

What is the GFR × plasma concentration equal to?

A)excretion rate
B)filtration fraction
C)clearance
D)renal blood flow
E)filtered load

Question 10

The clearance of what substance, which is not produced in the body but must be injected, provides a measure of glomerular filtration rate?

A)creatinine
B)PAH
C)inulin
D)urea
E)glucose

Question 11

What Starling force, which drives fluid out of the glomerulus, is relatively high (~60 mm Hg)due to the resistance of the efferent arterioles?

A)Bowman's capsule oncotic
B)glomerular capillary hydrostatic
C)Bowman's capsule hydrostatic
D)glomerular filtration
E)glomerular oncotic

Question 12

Which of the following describes movement from peritubular capillaries into the renal tubules?

A)filtration
B)excretion
C)secretion
D)reabsorption
E)micturition

Question 13

Over what range of mean arterial pressure does glomerular filtration rate remain stable due to intrinsic regulation?

A)80- 180 mm Hg
B)80- 120 mm Hg
C)70- 110 mm Hg
D)50- 150 mm Hg
E)80- 100 mm Hg

Question 14

What is the GFR/renal plasma flow equal to?

A)renal blood flow
B)filtered load
C)clearance
D)excretion rate
E)filtration fraction

Question 15

Which of the following substances is NOT secreted at any point into the renal tubules?

A)hydrogen
B)sodium
C)potassium
D)creatinine
E)choline

Question 16

The peritubular capillaries and vasa recta drain into what veins?

A)efferent
B)segmental
C)interlobar
D)arcuate
E)interlobular

Question 17

Under normal conditions, the osmotic pressure gradient across the glomerular capillaries tends to move water

A)back into the capillaries.
B)into the collecting duct.
C)into the parenchyma.
D)against its concentration gradient.
E)into the filtrate.

Question 18

In juxtamedullary nephrons, which region sets up the medullary osmotic gradient?

A)distal tubule
B)collecting duct
C)loop of Henle
D)proximal tubule
E)Bowman's capsule

Question 19

Which of the following is FALSE concerning glucose transport across the proximal tubule?

A)Glucose is actively transported across the apical membrane by cotransport with sodium.
B)Glucose transport requires energy.
C)Glucose is passively transported across the basolateral membrane by facilitated diffusion.
D)Glucose moves by paracellular transport.
E)Glucose is normally 100% reabsorbed.

Question 20

The clearance of which of the following substances is normally zero?

A)PAH
B)sodium
C)creatine
D)glucose
E)inulin

Question 21

What capillaries come off of the efferent arterioles associated with juxtamedullary nephrons?

A)lobular
B)arcuate
C)glomerulus
D)peritubular
E)vasa recta

Question 22

Which of the following are epithelial cells of Bowman's capsule that form part of the filtration barrier?

A)podocytes
B)macula densa cells
C)granular cells
D)mesangial cells
E)endothelial cells

Question 23

What hormone is secreted by the kidneys to increase red blood cell synthesis?

A)vitamin D
B)angiotensin
C)erythropoietin
D)renin
E)ANP

Question 24

After fluid passes through the entire proximal tubule, the fluid will enter the

A)collecting duct.
B)connecting tubule.
C)distal tubule.
D)Bowman's capsule.
E)loop of Henle.

Question 25

What effect does the sympathetic nervous system have on micturition?

A)Sympathetic activity inhibits muscles of the internal urethral sphincter inhibiting micturition.
B)Sympathetic activity inhibits muscles of the external urethral sphincter inhibiting micturition.
C)Sympathetic activity excites muscles of the internal urethral sphincter allowing micturition.
D)Sympathetic activity excites muscles of the internal urethral sphincter inhibiting micturition.
E)Sympathetic activity excites muscles of the external urethral sphincter allowing micturition.

Question 26

Which of the following can increase the filtered load of a particular solute?

A)increasing the rate of secretion
B)increasing the rate of reabsorption
C)decreasing the rate of excretion
D)decreasing the plasma concentration of the solute
E)increasing the glomerular filtration rate

Question 27

What structure filters the blood to regulate its composition?

A)bladder
B)ureter
C)liver
D)urethra
E)kidneys

Question 28

Which of the following conditions would increase glomerular filtration pressure?

A)increased Bowman's capsule pressure
B)increased protein in Bowman's space
C)increased protein content in the blood
D)increased resistance of the afferent arteriole
E)decreased resistance of the efferent arterioles

Question 29

What are the specialized cells of the juxtaglomerular apparatus in the afferent arteriole (and, to a lesser extent, the efferent arteriole)called?

A)macula densa
B)vasa recta
C)apparatus cells
D)granular cells
E)baroreceptors

Question 30

Located entirely within the cortex, reabsorption of water and certain solutes from which region is under hormonal control?

A)proximal tubule
B)distal tubule
C)Bowman's capsule
D)loop of Henle
E)collecting duct

Question 31

Changes in mean arterial pressure have the potential to alter glomerular filtration rate by directly altering which of the following?

A)efferent arteriole resistance
B)glomerular oncotic pressure
C)glomerular capillary hydrostatic pressure
D)Bowman's capsule hydrostatic pressure
E)Bowman's capsule oncotic pressure

Question 32

Blood leaves the and enters the glomerulus.

A)efferent arteriole
B)vasa recta
C)peritubular capillary
D)Bowman's capsule
E)afferent arteriole

Question 33

How is urine moved through the ureter?

A)contraction of the external urethral sphincter
B)pressure created within the renal pelvis
C)wavelike contractions of the ureter
D)contraction of the detrusor muscle
E)contraction of the internal urethral sphincter

Question 34

Which tubule drains into the minor calyces?

A)distal tubule
B)loop of Henle
C)collecting duct
D)proximal tubule
E)Bowman's capsule

Question 35

In comparison to the distal tubule, the proximal tubule has a

A)leakier epithelium and a larger apical surface area.
B)tighter epithelium and is more responsive to hormones.
C)leakier epithelium and is more responsive to hormones.
D)small apical surface area and is more responsive to hormones.
E)tighter epithelium and a larger apical surface area.

Question 36

The clearance of provides a measure of renal plasma flow rate.

A)urea
B)myoglobin
C)glucose
D)inulin
E)PAH

Question 37

Once produced, urine travels through the released into the external environment through the

A)collecting duct : urethra
B)urethra : ureter
C)ureter : urethra
D)renal hilus : ureter
E)collecting duct : ureter

Question 38

What is the site where filtrate enters renal tubules?

A)Bowman's capsule
B)loop of Henle
C)distal tubule
D)proximal tubule
E)collecting duct

Question 39

What is the process whereby protein- free plasma moves by bulk flow from the glomerulus into Bowman's capsules?

A)excretion
B)absorption
C)secretion
D)glomerular filtration
E)reabsorption

Question 40

Which capillaries branch from efferent arterioles of cortical nephrons and which branch from efferent arterioles of juxtamedullary nephrons?

A)interlobar and interlobular, respectively
B)arcuate and peritubular, respectively
C)peritubular and vasa recta, respectively
D)cortical and juxtamedullary, respectively
E)vasa recta and interlobular, respectively

Question 41

In diabetes mellitus, why does polyuria occur?

A)A lack of ADH decreases water reabsorption.
B)Hypoglycemia causes the excretion of a dilute urine.
C)Hyperglycemia causes some glucose to remain in the renal tubules which pulls water with it by osmosis.
D)Hyperglycemia causes increased permeability of the renal tubules to water.
E)A lack of insulin decreases water reabsorption.

Question 42

What is the brush border?

A)microvilli on the apical membrane of the proximal tubule
B)the epithelial cells of the renal corpuscle
C)microvilli on the apical membrane of Bowman's capsule
D)tight junctions between epithelial cells of the loops of Henle
E)tight junctions between epithelial cells of the distal tubule

Question 43

What are the three components of the loop of Henle?

A)descending limb, ascending limb, and the vasa recta
B)thick descending limb, thin descending limb, and thick ascending limb
C)descending limb, ascending limb, and the bend
D)proximal tubule, loop, and the distal tubule
E)descending limb, thin ascending limb, and thick ascending limb

Question 44

Which of the following forms the filtration barrier?

A)capillary endothelial cells only
B)podocytes only
C)basement membrane only
D)both capillary endothelial cells and basement membrane
E)capillary endothelial cells, basement membrane, and podocytes

Question 45

Which of the following equations for determining clearance is correct?

A)clearance = excretion rate / glomerular filtration rate
B)clearance = filtered load / glomerular filtration rate
C)clearance = filtered load × glomerular filtration rate
D)clearance = excretion rate × plasma concentration
E)clearance = excretion rate / plasma concentration

Question 46

How does the sympathetic nervous system decrease glomerular filtration rate?

A)stimulates constriction of the efferent arteriole only
B)stimulates constriction of both the afferent and efferent arterioles
C)stimulates contraction of mesangial cells
D)stimulates relaxation of the mesangial cells
E)stimulates constriction of the afferent arteriole only

Question 47

During tubuloglomerular feedback of glomerular filtration rate, paracrines secreted from what structure(s)cause constriction of the afferent arteriole?

A)juxtaglomerular cells
B)glomerulus
C)mesangial cells
D)macula densa
E)proximal tubule

Question 48

If the glomerular filtration rate is 150 mL/min, renal blood flow is 750 mL/min, and the plasma concentration of solute X is 10 ng/mL, then what is the filtered load of X?
A)1500 ng/min

A)50 ng/min
B)10%
B)7500 ng/min
E)20%

Question 49

To voluntarily control urination, the nervous system innervates the .

A)somatic : external urethral sphincter
B)somatic : detrusor muscle
C)autonomic : external urethral sphincter
D)autonomic : internal urethral sphincter
E)somatic : internal urethral sphincter

Question 50

What is the (urine concentration × urine flow rate)/plasma concentration equal to?

A)renal blood flow
B)filtration fraction
C)filtered load
D)clearance
E)excretion rate

Question 51

The micturition reflex is activated by the stretch of the bladder, which activates what?

A)parasympathetic efferents
B)stretch receptors
C)sympathetic afferents
D)parasympathetic afferents
E)somatic afferents

Question 52

If the glomerular filtration rate is 150 mL/min, renal blood flow is 750 mL/min, and the plasma concentration of solute X is 10 ng/mL, then what is the filtration fraction?

A)1500 ng/min
B)50 ng/min
C)20%
D)75 ng/min
E)10%

Question 53

Stretching of the bladder reflexively causes all of the following EXCEPT

A)excitation of parasympathetic neurons, causing the detrusor muscles to contract.
B)opening of the urethral sphincters.
C)inhibition of somatic neurons to the external urethral sphincter, causing the sphincter to open.
D)excitation of sympathetic neurons, causing the internal urethral sphincter to relax.
E)micturition.

Question 54

What is the primary barrier to reabsorption in the renal tubules?

A)tubule epithelial cell
B)capillary endothelial cell
C)peritubular space
D)tubule basement membrane
E)capillary basement membrane

Question 55

Calculate renal clearance of X given the following information: GFR = 100 mL/min, urine flow rate = 5 mL/min, plasma concentration of X = 10 mg/mL, urine concentration of X = 50 mg/mL.

A)Y is freely filterable.
B)Y is reabsorbed.
C)Y is secreted.
D)Y is neither reabsorbed nor secreted.
E)Y is not freely filtered.

Question 56

The clearance of what substance provides the best estimate of renal blood flow rate?

A)inulin
B)PAH
C)glucose
D)sodium
E)creatine

Question 57

What is the sum of Starling's forces within the renal corpuscle called?

A)glomerular filtration rate
B)glomerular filtration pressure
C)glomerular filtration volume
D)glomerular capillary hydrostatic pressure
E)glomerular oncotic pressure

Question 58

Constriction of which vessel, by intrinsic or extrinsic mechanisms, decreases glomerular filtration rate?

A)glomerulus
B)efferent arteriole
C)afferent arteriole
D)peritubular capillary
E)vasa recta

Question 59

Which of the following equations is correct for calculating the filtered load?

A)glomerular filtration rate / renal plasma flow
B)glomerular filtration pressure × plasma concentration of solute
C)glomerular filtration pressure / renal plasma flow
D)glomerular filtration rate × plasma concentration of solute
E)glomerular filtration pressure × plasma concentration of solvent

Question 60

Contraction of mesangial cells results in a(n)_, which decreases glomerular filtration.

A)dilation of the afferent arterioles
B)increase in surface area of capillaries available for filtration
C)decrease in surface area of capillaries available for filtration
D)dilation of the efferent arterioles
E)constriction of the afferent arterioles

Question 61

The amount of a substance excreted from the kidneys is calculated by which of the following equations?

A)filtration - (secretion × reabsorption)
B)filtration + secretion - reabsorption
C)filtration + secretion + reabsorption
D)filtration - secretion - reabsorption
E)filtration + (secretion × reabsorption)

Question 62

What are the conical sections of the renal medulla called?

A)renal pyramids
B)major calyces
C)renal pelvis
D)minor calyces
E)renal cortex

Question 63

Which cells of the afferent arteriole secrete renin?

A)endothelial cells
B)macula densa cells
C)podocytes
D)mesangial cells
E)granular cells

Question 64

The clearance of what substance provides the best estimate of glomerular filtration rate?

A)inulin
B)PAH
C)creatine
D)glucose
E)sodium

Question 65

Which of the four Starling forces for glomerular filtration is incorrectly paired with the direction it favors (filtration or absorption)?

A)Bowman's capsule oncotic pressure : filtration
B)Bowman's capsule hydrostatic pressure : absorption
C)glomerular capillary hydrostatic pressure : filtration
D)glomerular capillary osmotic pressure : filtration
E)glomerular capillary oncotic pressure : absorption

Question 66

The juxtaglomerular apparatus describes the unique region of the nephron where the

A)afferent arteriole is in contact with the distal tubule.
B)afferent arteriole is in contact with the proximal tubule.
C)efferent arteriole is in contact with the distal tubule.
D)afferent and efferent arterioles are in contact with the distal tubule.
E)afferent and efferent arterioles are in contact with the proximal tubule.

Question 67

What is the process whereby molecules are selectively transported from the peritubular fluid to the lumen of the renal tubules?

A)glomerular filtration
B)excretion
C)reabsorption
D)secretion
E)absorption

Question 68

The primary function of the kidneys involves regulating the and the of plasma and interstitial fluid.

A)composition : osmolarity
B)volume : temperature
C)pressure : volume
D)volume : composition
E)temperature : composition

Question 69

Filtrate moves from what structure to the loop of Henle?

A)distal tubule
B)loop of Henle
C)Bowman's capsule
D)collecting duct
E)proximal tubule

Question 70

Which of the following describes elimination of urine from the body?

A)excretion
B)secretion
C)micturition
D)reabsorption
E)filtration

Question 71

In tubuloglomerular feedback, an increase in glomerular filtration rate would increase the , thereby stimulating the release of a paracrine factor from the macula densa that would
)

A)flow of tubular fluid : constrict the efferent arteriole
B)afferent arteriolar pressure : increase filtrate flow
C)flow of tubular fluid : constrict the afferent arteriole
D)flow of tubular fluid : dilate the afferent arteriole
E)afferent arteriolar pressure : constrict the afferent arteriole

Question 72

Which of the following occurs during micturition?

A)The detrusor muscles relax, muscles of the internal urethral sphincter contract, and muscles of the external urethral sphincter relax.
B)The detrusor muscles contract, muscles of the internal urethral sphincter relax, and muscles of the external urethral sphincter relax.
C)The detrusor muscles relax, muscles of the internal urethral sphincter relax, and muscles of the external urethral sphincter relax.
D)The detrusor muscles relax, muscles of the internal urethral sphincter contract, and muscles of the external urethral sphincter contract.
E)The detrusor muscles contract, muscles of the internal urethral sphincter contract, and muscles of the external urethral sphincter contract.

Question 73

What two structures make up the renal corpuscle?

A)major and minor calyces
B)nephron and collecting duct
C)proximal straight and proximal convoluted tubules
D)Bowman's capsule and glomerulus
E)afferent and efferent arterioles

Question 74

What condition(s)must exist for a solute to be passively reabsorbed from the renal tubules?

A)The solute must be able to permeate the membrane of the tubule epithelial cells, and the solute must be in greater concentration in the plasma than tubule fluid.
B)The solute must be able to permeate the membrane of the tubule epithelial cells, and the solute must be in greater concentration in the tubule fluid than plasma.
C)The solute must be able to permeate the membrane of the capillary endothelial cells, and the solute must be in greater concentration in the tubule fluid than plasma.
D)The solute must be able to permeate the membrane of the capillary endothelial cells, and the solute must be in greater concentration in the plasma than tubule fluid.
E)The solute must be able to permeate the membrane of the tubule epithelial cells and capillary endothelial cells. Its concentration is irrelevant.

Question 75

Filtration occurs across which capillary bed?

A)afferent arteriole
B)peritubular capillary
C)glomerulus
D)vasa recta
E)efferent arteriole

Question 76

When carrier proteins are saturated, they are said to be working at what?

A)increased affinity
B)transport maximum
C)increased capacity
D)diminished capacity
E)active reabsorptive state

Question 77

During what renal process are molecules selectively removed from the tubule lumen, moved into the interstitial space, and removed from the kidneys by the peritubular capillaries and the vasa recta?

A)filtration
B)secretion
C)absorption
D)reabsorption
E)excretion

Question 78

Substance X is freely filtered at the glomerulus. 3 mmole X is filtered, 2 mmole X is reabsorbed, and 2 mmole X is secreted per minute. How much X is excreted per minute?

A)1 mmole
B)2 mmole
C)3 mmole
D)4 mmole
E)5 mmole

Question 79

Tubular epithelial cells of the collecting duct and distal tubule contain receptors for what hormone that stimulates water reabsorption?

A)erythropoietin
B)atrial natriuretic peptide
C)renin
D)aldosterone
E)antidiuretic hormone

Question 80

Solutes that enter the lumen of the renal tubules are excreted unless they are

A)filtered.
B)degraded.
C)bound to receptors.
D)reabsorbed.
E)secreted.