Deck 13: The Urinary System

Question 1

Which of the following is NOT a function of the kidneys

A)to act directly on the interstitial fluid, the fluid that bathes the cells, to maintain constancy in its composition
B)to contribute significantly to long-term regulation of arterial blood pressure by maintaining the proper plasma volume
C)to excrete metabolic waste products
D)to assist in maintaining the proper acid-base balance of the body

Answer 1

A

Question 2

What is the functional unit of the kidney

A)glomerulus
B)nephron
C)medulla
D)juxtaglomerular apparatus

Answer 2

B

Question 3

Which of these statements does NOT describe juxtamedullary nephrons

A)Their tubules lie in the renal cortex.
B)They are important in the ability of the kidneys to concentrate urine.
C)Their loops of Henle dip deep into the medulla.
D)Their peritubular capillaries form vasa recta.

Answer 3

A

Question 4

Which of these statements applies to the blood that flows through the kidneys

A)normally about 20 to 25 percent of the total cardiac output
B)all filtered through the glomeruli
C)all used to supply the renal tissue with O₂ and nutrients
D)normally about 40 percent of the total cardiac output

Question 5

Which nephron structure is especially important in the kidney's ability to produce urine of varying concentration

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

Question 6

Which of the following is NOT involved in autoregulation of the GFR

A)a myogenic mechanism in which the afferent arteriole automatically constricts when it is stretched
B)a tubuloglomerular feedback mechanism in which vasoactive chemicals released from the juxtaglomerular apparatus bring about afferent arteriolar vasoconstriction
C)sympathetically induced vasoconstriction of the afferent arterioles
D)a MAP of 80 to 180 mmHg

Question 7

Filtrate does NOT pass through which of these structures

A)glomerular capillary pores
B)basement membrane
C)podocytes
D)filtration slits

Question 8

What is the average glomerular filtration rate

A)125 mL/min
B)625 mL/min
C)750 mL/day
D)1140 mL/day

Question 9

Which of the following is the specialized nephron capillary bed where filtration occurs

A)afferent arteriole
B)efferent arteriole
C)glomerulus
D)peritubular bed

Question 10

Which statement describes glomerular filtration

A)It occurs in the loop of Henle.
B)It is the process by which plasma water, electrolytes, and small molecules are separated from blood cells and protein.
C)It is the process by which a substance is transported from the tubular fluid to the peritubular capillaries.
D)It is greater when glomerular capsular pressure is higher.

Question 11

What is the renal process whereby substances are selectively transferred from the peritubular blood into the renal tubule

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

Question 12

Which of the following is NOT associated with juxtamedullary nephrons

A)importance in the ability of the kidneys to produce urine of varying concentration
B)long loops of Henle
C)peritubular capillaries forming vasa recta
D)glomeruli located in medulla

Question 13

What is the order of flow of filtrate through the nephron components and associated structures

A)ascending limb of loop of Henle; proximal tubule; distal tubule; collecting tubule; Bowman's capsule; descending limb of loop of Henle
B)Bowman's capsule; proximal tubule; descending limb of loop of Henle; ascending limb of loop of Henle; distal tubule; collecting tubule
C)Bowman's capsule; distal tubule; proximal tubule; collecting tubule; descending limb of loop of Henle; ascending limb of loop of Henle
D)collecting tubule; Bowman's capsule; proximal tubule; descending limb of loop of Henle; ascending limb of loop of Henle; distal tubule

Question 14

Vasa recta are associated with which of these structures

A)afferent arterioles
B)efferent arterioles
C)cortical nephrons
D)juxtamedullary nephrons

Question 15

Which of the following is NOT a function of the kidneys

A)to excrete metabolic wastes
B)to maintain proper plasma volume
C)to secrete aldosterone to regulate sodium
D)to maintain proper osmolarity of body fluids

Question 16

Which of these forces favours glomerular filtration

A)glomerular capillary osmotic pressure
B)capsular osmotic pressure
C)glomerular capillary hydrostatic pressure
D)capsular hydrostatic pressure

Question 17

Which of these statements describes glomerular filtrate

A)It is plasma-free blood.
B)It is formed as a result of passive forces acting across the glomerular membrane.
C)It does not contain foreign compounds.
D)Its rate is increased by increased plasma protein level.

Question 18

Which statement describes the process of glomerular filtration

A)Bowman's capsule hydrostatic pressure opposes filtration.
B)Its rate is limited by a Tm.
C)All the plasma that enters the glomerulus is filtered.
D)All the plasma that enters the glomerulus is reabsorbed.

Question 19

Which factor would reduce net filtration pressure the most

A)vasodilation of the afferent arteriole
B)vasocontraction of the efferent arteriole
C)a low capsular hydrostatic pressure
D)a large increase in blood colloid osmotic pressure

Question 20

The glomerular capillary blood pressure in the nephron is 78 mmHg.The Bowman's capsular hydrostatic pressure is 24 mmHg.The colloidal osmotic pressure is 18 mmHg.What is the net filtration pressure

A)18 mmHg
B)26 mmHg
C)36 mmHg
D)42 mmHg

Question 21

What is the location of the Na⁺-K⁺ ATPase transport system that plays a pivotal role in much of tubular reabsorption

A)luminal membrane of tubular cells
B)basolateral membrane of tubular cells
C)podocytes
D)glomerular capillary membrane

Question 22

Which statement does NOT describe tubular reabsorption

A)It refers to the movement of a substance from the peritubular capillary blood into the tubular fluid.
B)It occurs by either active or passive transport.
C)It involves the process of transepithelial transport.
D)It is highly selective and variable.

Question 23

Which one of these statements does NOT correctly apply to extrinsic control of the GFR

A)It is mediated by sympathetic nervous system input to the afferent arterioles.
B)It is aimed at the regulation of arterial blood pressure.
C)It is an autoregulatory mechanism.
D)Baroreceptors are involved.

Question 24

Which of these statements does NOT refer to tubular reabsorption

A)It refers to the movement of a substance from the tubular fluid to the peritubular capillary blood.
B)It is important for the conservation of substances important to the body, such as Na⁺, Cl-, glucose, and amino acids.
C)It can occur by active or passive transport mechanisms.
D)It takes place only in the proximal tubule.

Question 25

Which of these statements does NOT describe the proximal tubule

A)It reabsorbs about 65 percent of the filtered water.
B)It receives the filtrate from Bowman's capsule.
C)It is the location where glucose is reabsorbed.
D)It is the site of action of renin.

Question 26

Which of the following occurs after stimulation of the macula densa cells

A)vasodilation of the afferent arteriole
B)secretion of erythropoietin
C)increased GFR
D)vasoconstriction of the afferent arteriole

Question 27

Which of these statements does NOT refer to the juxtaglomerular apparatus

A)It secretes renin in response to sodium depletion or plasma volume reduction.
B)It is a thickened region of specialized cells at a point where the distal tubule comes into intimate contact with the afferent and efferent arterioles of the same nephron.
C)It is where reabsorption of sodium occurs.

Question 28

Which of these statements refers to aldosterone secretion

A)It occurs in the kidney.
B)It is stimulated by angiotensin II.
C)It is controlled by the concentration of Cl-.
D)It is secreted by the macula densa.

Question 29

In which part of the kidney does the greatest percentage of Na⁺ reabsorption take place

A)proximal tubule
B)loop of Henle
C)distal tubule
D)collecting tubule

Question 30

Which of these statements does NOT refer to aldosterone

A)It stimulates Na⁺ reabsorption in the distal and collecting tubules.
B)It is secreted by the JG apparatus.
C)It stimulates K⁺ secretion in the distal tubule.
D)It is secreted by the adrenal cortex.

Question 31

What stimulates sodium reabsorption in the distal portions of the nephron

A)atrial natriuretic peptide
B)vasopressin
C)angiotensin II
D)aldosterone

Question 32

Which of these substances is NOT reabsorbed by the proximal convoluted tubule

A)sodium
B)lipids
C)glucose
D)water

Question 33

Into which of these structures does most reabsorption occur

A)proximal convoluted tubule
B)glomerulus
C)distal convoluted tubule
D)loop of Henle

Question 34

Which of these statements does NOT refer to angiotensin I

A)It is formed as a result of activation of angiotensinogen by renin.
B)It is transformed into angiotensin II as a result of converting enzyme action in the lungs.
C)It acts on the adrenal cortex to stimulate aldosterone secretion.

Question 35

Which of these statements does NOT refer to the macula densa

A)It consists of specialized tubular cells in the juxtaglomerular apparatus.
B)It is at a point where the distal tubule passes through.
C)It secretes renin.
D)It consists of specialized arteriolar smooth-muscle cells in the juxtaglomerular apparatus.

Question 36

Which of the following happens when blood volume becomes abnormally low

A)Sodium reabsorption is diminished.
B)Dilute urine is formed.
C)Renin catalyzes the conversion of angiotensinogen.
D)Aldosterone is secreted by the kidney.

Question 37

Which of the following would decrease the GFR

A)a fall in plasma protein concentration
B)an obstruction such as a kidney stone in the tubular system
C)vasodilation of the afferent arterioles
D)a high hydrostatic pressure

Question 38

When arterial blood pressure is elevated above normal, which compensatory change in renal function occurs as a result of the baroreceptor reflex

A)afferent arteriolar vasoconstriction
B)efferent arteriolar vasoconstriction
C)reduction in GFR
D)afferent arteriolar vasodilation

Question 39

Which one of these statements is NOT a step in transepithelial transport

A)movement of the substance through the cytosol of the tubular cell
B)movement of the substance across the glomerular capillary wall
C)movement of the substance across the luminal membrane of the tubular cell
D)movement of the substance through the interstitial fluid

Question 40

In normal conditions, which portion of the renal tubules absorbs the largest amount of sodium

A)proximal convoluted tubule
B)descending limb of loop of Henle
C)ascending limb of loop of Henle
D)distal convoluted tubule

Question 41

Which of these statements does NOT refer to urea

A)It is a waste product resulting from the breakdown of protein.
B)It is passively reabsorbed at the end of the proximal tubule down a concentration gradient created by the osmotic-induced reabsorption of water from the proximal tubule.
C)Recycling between the late portion of the collecting tubule and the long loops of Henle contributes to medullary hypotonicity.
D)Only half the filtered amount is eliminated from the plasma.

Question 42

Which of the following does NOT play a role in Na⁺ reabsorption

A)renin
B)vasopressin
C)angiotensinogen
D)aldosterone

Question 43

Which of these statements does NOT describe urea

A)It is the waste product with the smallest molecular size in the glomerular filtrate.
B)It is in greater concentration at the end of the proximal tubule than in other body fluids.
C)It has a clearance rate greater than GFR.

Question 44

Which of these statements does NOT describe sodium reabsorption

A)It plays a role in glucose, amino acid, and urea reabsorption in the proximal tubule.
B)It is under hormonal control in the distal tubule.
C)In the loop of Henle, it contributes to the formation of concentrated urine.
D)It is inhibited by aldosterone.

Question 45

Which of these statements does NOT refer to atrial natriuretic peptide (ANP)

A)It is released from the cardiac atria when the ECF volume is reduced.
B)It inhibits Na⁺ reabsorption in the distal parts of the nephron.
C)It inhibits renin secretion by the kidneys.
D)It inhibits aldosterone secretion by the adrenal cortex.

Question 46

Which of these statements does NOT describe water reabsorption

A)It occurs by active transport in the distal and collecting tubules.
B)It occurs to the greatest extent in the proximal convoluted tubule.
C)It is under vasopressin control in the distal and collecting tubules.
D)It occurs by active transport in the distal and collecting tubules.

Question 47

Which of these statements does NOT describe water reabsorption

A)It occurs passively by osmosis in the proximal tubule.
B)It is under the control of vasopressin in the distal and collecting tubules.
C)It occurs by active transport in the distal and collecting tubules.
D)It occurs passively in the descending limb of loop of Henle.

Question 48

Which of these substances is NOT normally secreted into the tubule

A)hydrogen ions
B)potassium ions
C)glucose
D)water molecules

Question 49

Which of these statements describes the renal threshold

A)It is the maximum amount of a particular substance that can be excreted in the urine per unit of time.
B)It is the maximum amount of a particular substance that the tubular cells are capable of actively reabsorbing per unit of time.
C)It is the plasma concentration of a particular substance at which its Tm is reached and the substance first appears in the urine.
D)It is the maximum amount of waste product that can be concentrated in the urine per unit of time.

Question 50

What are the distal and collecting tubules the site of

A)aldosterone and vasopressin action
B)the organic ion secretory systems
C)the cotransport carriers for glucose and amino acid reabsorption
D)glucose reabsorption

Question 51

Given the following data for substance X, how much of substance X is filtered, reabsorbed, and excreted GFR = 125 mL/min; Tm = 125 mg/min at a plasma concentration of 200 mg/100 mL

A)125 mg/min filtered, 125 mg/min reabsorbed, 0 mg/min excreted
B)200 mg/min filtered, 125 mg/min reabsorbed, 75 mg/min excreted
C)250 mg/min filtered, 125 mg/min reabsorbed, 125 mg/min excreted
D)250 mg/min filtered, 200 mg/min reabsorbed, 50 mg/min excreted

Question 52

Which of these statements applies to water reabsorption

A)It is under the control of vasopressin throughout the length of the nephron.
B)The ascending limb of the loop of Henle is always impermeable to water.
C)Vasopressin makes the distal and collecting tubules impermeable to water.
D)Fifteen percent of the filtered water osmotically follows the absorption of Na⁺ and other solutes in the proximal tubule.

Question 53

What is the energy required for glucose reabsorption used for

A)to run the Na⁺-K⁺ ATPase pump
B)to run the Na⁺-glucose cotransport carrier
C)to maintain the Tm for glucose
D)to produce aldosterone-induced protein, which increases the permeability of the proximal tubular cells to glucose

Question 54

Which of these statements describes tubular maximum (Tm)

A)It is the rate of glomerular filtration.
B)It is the rate at which a substance can be reabsorbed because of saturation of the carrier molecule.
C)It is the rate at which a substance can be cleared from the blood.
D)It is the percentage of renal blood flow that can be converted to filtrate.

Question 55

Why is glucose NOT normally found in the urine

A)Glucose does not get filtered out of the glomerulus.
B)Glucose is not found in the blood.
C)Glucose is kept in the blood.
D)Glucose is usually reabsorbed by renal tubule cells.

Question 56

Which of these plasma constituents is NOT regulated by the kidneys

A)glucose
B)Na+
C)H⁺
D)phosphate

Question 57

Where is water reabsorption under the control of vasopressin

A)along the entire length of the nephron
B)only in the loop of Henle
C)only in the distal and collecting tubules
D)only in the proximal tubule

Question 58

What is the normal glucose concentration in the plasma

A)30 mg/100 mL
B)60 mg/100 mL
C)100 mg/100 mL
D)180 mg/100 mL

Question 59

Which of these statements does NOT refer to atrial natriuretic peptide

A)It is secreted by the heart when atrial pressure is high.
B)It results in decreased glomerular filtration rate.
C)It inhibits aldosterone activity.
D)Its action is antagonistic to the action of testosterone.

Question 60

Which of these statements does NOT refer to the tubular maximum (Tm)

A)It is the maximum amount of a substance that the tubular cells can actively transport within a given time period.
B)It is the maximum rate at which a substance is filtered at the glomerulus.
C)It occurs when the membrane carrier becomes saturated.
D)It is the maximum amount of a substance that can be reabsorbed by the renal tubules.

Question 61

Which of these statements does NOT apply to potassium

A)It is secreted in the proximal tubule.
B)It is actively secreted in the distal and collecting tubules.
C)Its secretion is controlled by aldosterone.
D)Its secretion is linked with Na⁺ reabsorption by the Na⁺-K⁺ pump.

Question 62

What happens to tubular secretion when the extracellular fluid becomes too acidic

A)No ionic substance is affected.
B)Hydrogen ions decrease.
C)Hydrogen ions increase.
D)Sodium ions decrease.

Question 63

Where does tubular secretion of foreign substances such as drugs generally occur

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

Question 64

Which of the following does NOT stimulate aldosterone secretion

A)an increase in plasma K⁺
B)a decrease in plasma K⁺
C)overhydration
D)low plasma sodium level

Question 65

Which of the following pertains to the ascending limb of the loop of Henle

A)NaCl passively leaves the tubular fluid down its concentration gradient.
B)NaCl is actively transported into the interstitial fluid, leaving water behind because the tubular cells are not permeable to water.
C)K⁺ is secreted.
D)Aldosterone stimulates Na⁺ reabsorption.

Question 66

The plasma clearance of a substance can be used to calculate the glomerular filtration rate (GFR) if that substance is freely filtered at the glomerulus and is

A)secreted and reabsorbed by the tubules.
B)neither reabsorbed nor secreted by the tubules.
C)secreted by the tubules but not reabsorbed by the tubules.
D)reabsorbed by the tubules but not secreted by the tubules.

Question 67

Which statement applies to inulin

A)It is filtered, not reabsorbed, but secreted.
B)It is filtered, not reabsorbed, and not secreted.
C)It is filtered, reabsorbed, and not secreted.
D)It is filtered, reabsorbed, and secreted.

Question 68

Which part of the juxtamedullary nephron is responsible for establishing the vertical osmotic gradient in the medulla of the kidney

A)loop of Henle
B)afferent arteriole
C)collecting duct
D)juxtaglomerular apparatus

Question 69

Which of these statements describes tubular secretion

A)It refers to the movement of a substance from the peritubular capillary blood into the tubular lumen.
B)It can occur by active or passive transport mechanisms.
C)It can occur in the proximal convoluted tubules and is stimulated by aldosterone.
D)It is a supplemental mechanism that hastens elimination of compounds from the body.

Question 70

Which statement describes the loop of Henle of juxtamedullary nephrons

A)The ascending limb of the loop of Henle is freely permeable to H₂Oa. and NaCl.
B)The filtrate is isotonic as it enters the loop of Henle, hypertonic at the tip of the loop, and hypotonic as it leaves the loop of Henle.
C)The descending limb of the loop of Henle actively transports NaCl out of the tubule and into the interstitial fluid.
D)It is located at the junction of the renal cortex and the medulla.

Question 71

What is the major waste product of nitrogen metabolism

A)plasma proteins
B)amino acids
C)glucose
D)urea

Question 72

Which of the following does NOT apply to the ascending limb of the loop of Henle

A)actively transports NaCl into the surrounding interstitial fluid
B)impermeable to water
C)found in the renal cortex
D)thick wall

Question 73

Which of these factors does NOT contribute to the establishment of a vertical osmotic gradient in the interstitial fluid of the renal medulla

A)the renin-angiotensin-aldosterone system
B)countercurrent multiplication in the long loops of Henle of juxtamedullary nephrons
C)urea recycling between the late portion of the collecting tubule and the long loops of Henle
D)active transportation of sodium out of the ascending limb of the loop of Henle

Question 74

Which of these statements describes why tubular secretion is important

A)It is involved in the renal regulation of hydrogen ion concentration.
B)It is for the elimination of metabolic waste products from the body.
C)It is in the renal regulation of sodium balance.
D)It is for glucose secretion.

Question 75

Which segment of the nephron is NOT permeable to H₂O a., even in the presence of vasopressin

A)proximal tubule
B)ascending limb of the loop of Henle
C)descending limb of the loop of Henle
D)distal tubule

Question 76

Which statement does NOT describe the medullary vertical osmotic gradient

A)The loops of Henle of juxtamedullary nephrons establish a medullary vertical osmotic gradient by means of countercurrent multiplication.
B)The vasa recta enable the medulla to be supplied with blood while conserving the medullary vertical osmotic gradient by means of countercurrent exchange.
C)The countercurrent system establishes and maintains a medullary vertical osmotic gradient ranging from 300 to 1200 mOsm/litre.
D)The collecting tubules of the juxtamedullary nephrons but not the cortical nephrons descend through the medullary vertical osmotic gradient before emptying into the renal pelvis.

Question 77

Which of these statements applies to renal excretion

A)It is the removal of substances that were filtered at the glomerulus or secreted but not reabsorbed.
B)It is the process by which a substance moves from the peritubular capillary blood to the tubular fluid.
C)It conserves substances that are important to the body.
D)It occurs by active transport of substances into the urinary bladder.

Question 78

What establishes the medullary vertical osmotic gradient by means of countercurrent multiplication

A)loops of Henle of juxtamedullary nephrons
B)loops of Henle of cortical nephrons
C)vasa recta of juxtamedullary nephrons
D)vasa recta of cortical nephrons

Question 79

What happens to the concentration of tubular fluid as it flows up the ascending loop of Henle

A)Its concentration remains unchanged.
B)Its concentration increases.
C)Its pressure decreases.
D)Its concentration decreases.

Question 80

Which statement applies to plasma clearance

A)the time required for plasma to filter from blood in the glomerulus
B)the amount of a substance cleared and appearing in the urine in one minute
C)the amount of a substance in plasma filtered in one minute
D)the volume of plasma that is completely cleared of a substance by the kidneys in one minute