Deck 12: The Urinary System

Question 1

What would decrease the GFR?

A) a fall in plasma protein concentration
B) an obstruction such as a kidney stone in the tubular system, which increases Bowman's capsule hydrostatic pressure
C) vasodilation of the afferent arterioles
D) a high hydrostatic pressure

Answer 1

B

Question 2

Which is the functional unit of the kidney?

A) Glomerulus
B) Nephron
C) Medulla
D) juxtaglomerular apparatus

Answer 2

B

Question 3

Which factor would reduce the net filtration pressure the most?

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

Answer 3

C

Question 4

What is NOT associated with juxtamedullary nephrons?

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

Question 5

Below is a listing of nephron components and associated structures:
1)descending limb of loop of Henle
2)Bowman's capsule
3)collecting tubule
4)ascending limb of loop of Henle
5)distal tubule
6)proximal tubule
What is the correct flow of filtrate through these structures?

A) 4, 6, 5, 3, 2, 1
B) 2, 6, 1, 4, 5, 3
C) 2, 5, 6, 3, 1, 4
D) 3, 2, 6, 1, 4, 5

Question 6

Which of the following is true about 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 7

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 8

Which statement about juxtamedullary nephrons is INCORRECT?

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.

Question 9

What is NOT a function of the kidneys?

A) excretion of metabolic wastes
B) maintaining proper plasma volume
C) secreting aldosterone to regulate sodium
D) maintaining proper osmolarity of body fluids

Question 10

Which statement concerning the process of glomerular filtration is correct?

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

Question 11

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

A) 18 mm Hg
B) 26 mm Hg
C) 36 mm Hg
D) 42 mm Hg

Question 12

What is the specialized nephron capillary bed where filtration occurs?

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

Question 13

Which statement is correct for glomerular filtration rate? The glomerular filtration rate _____.

A) It averages 125 mL/min.
B) It averages 75 litres/day.
C) It represents 60 to 65 percent of the cardiac output.
D) It averages 100 litres/day.

Question 14

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 15

What is NOT a function of the kidneys?

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

Question 16

What are vasa recta associated with?

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

Question 17

What is/are NOT the function/s of peritubular capillaries?

A) They drain into glomeruli.
B) They take up the substances that are reabsorbed by the tubules.
C) They supply substances that are secreted by the tubules.

Question 18

Which statement is correct concerning glomerular filtrate?

A) It is a 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 because these substances are secreted by special transport mechanisms in the proximal tubule instead.
D) Its rate is increased by increased plasma protein level.

Question 19

Which statement is correct concerning glomerular filtration?

A) It occurs in the loop of Henle.
B) It is the process by which plasma water, electrolytes, and small molecules, which enter Bowman's capsule, are separated from blood cells and protein, which remain in the glomerular capillaries.
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 20

What does filtrate NOT pass through?

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

Question 21

Afferent arteriolar vasoconstriction _____ blood flow into the glomerulus,which causes the glomerular-capillary blood pressure to _____,leading to a(n)_____ in the net filtration pressure and a resultant _____ in the GFR.

A) increases, increase, increase, increase
B) decreases, decrease, decrease, decrease
C) increases, increase, decrease, decrease
D) decreases, decrease, increase, increase

Question 22

Which statement is NOT true for the myogenic mechanism?

A) It causes the afferent arteriole to constrict when blood pressure is too high.
B) It may result from stretching of vascular smooth muscle.
C) It is under motor system control.

Question 23

What 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 tubulo-glomerular feedback mechanism in which vasoactive chemicals released from the juxtaglomerular apparatus bring about afferent arteriolar vasoconstriction
C) sympathetically induced vasoconstriction of the afferent arterioles

Question 24

Which statement is NOT true for the macula densa?

A) It consists of specialized tubular cells in the juxtaglomerular apparatus
B) It consists of specialized arteriolar smooth-muscle cells in the juxtaglomerular apparatus
C) It secretes renin

Question 25

Which statement regarding tubular reabsorption is INCORRECT?

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 26

Why is glucose NOT normally found in the urine?

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

Question 27

Which statement is NOT true for 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

Question 28

Which statement regarding tubular maximum (Tm)is NOT true?

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.

Question 29

Into which structure does most reabsorption occur?

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

Question 30

Which statement is NOT true concerning 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.

Question 31

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 32

What is NOT reabsorbed by the proximal convoluted tubule?

A) sodium
B) lipids
C) glucose

Question 33

Which statement regarding tubular reabsorption is NOT true?

A) It involves the movement of substances from the peritubular capillaries into the tubular fluid.
B) It involves the movement of substances from the tubular fluid into the peritubular capillaries.
C) It is considered to be active if any one of the five steps of transepithelial transport is active.

Question 34

Which statement regarding tubular maximum (Tm)is correct?

A) It is 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 35

Which statement regarding the proximal tubule is NOT true?

A) It reabsorbs about 65 percent of the filtered water.
B) It is the site of action of renin.
C) It is the location where glucose is reabsorbed.

Question 36

What does tubular reabsorption NOT involve?

A) active transport
B) endocytosis
C) facilitated diffusion

Question 37

Which statement 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 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) afferent arteriolar vasodilation
C) reduction in GFR
D) efferent arteriolar vasoconstriction

Question 39

Which of the following forces does NOT oppose/s glomerular filtration?

A) blood colloid-osmotic pressure
B) Bowman's capsule hydrostatic pressure
C) glomerular-capillary blood pressure

Question 40

What occurs after stimulation of the macula densa cells?

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

Question 41

What does NOT play a role in Na⁺ reabsorption?

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

Question 42

What is the energy required for glucose reabsorption used for?

A) to run the Na+-K+ ATPase pump
B) to run the Na+-glucose co-transport 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 43

Which statement is NOT attributable to atrial natriuretic peptide (ANP)?

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

Question 44

Which statement regarding aldosterone is NOT true?

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.

Question 45

Which statement regarding angiotensin I is NOT true?

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 46

Which plasma constituent is NOT regulated by the kidneys?

A) Glucose
B) Na+
C) H+
D) Phosphate

Question 47

Which statement regarding sodium reabsorption is INCORRECT?

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) Approximately 0.5 percent of sodium is reabsorbed on a daily basis.

Question 48

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

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 49

Which statement regarding the renal threshold is correct?

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 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 51

Which statement regarding atrial natriuretic peptide is NOT true?

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.

Question 52

Which statement is correct for reabsorption of chloride?

A) It is active.
B) It is passive.
C) It is dependent on the amount of sodium reabsorbed.
D) It is passive and dependent on the amount of sodium reabsorbed.

Question 53

What is the major waste product of nitrogen metabolism?

A) plasma proteins
B) Urea
C) Glucose
D) amino acids

Question 54

Which statement about Na⁺ reabsorption is INCORRECT?

A) It uses 80 percent of the energy requirement of the kidney.
B) It is under control of the hormone aldosterone in the distal portions of the nephron.
C) It is not linked to the reabsorption of amino acids and urea.

Question 55

Where does the greatest percentage of Na⁺ reabsorption takes place?

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

Question 56

What is the normal glucose concentration in the plasma in terms of mg per 100 mL?

A) 30
B) 60
C) 100
D) 180

Question 57

Which statement regarding aldosterone secretion is INCORRECT?

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

Question 58

Which statement regarding the juxtaglomerular apparatus is NOT true?

A) It is a combination of specialized tubular and vascular cells at a point where the beginning of the distal tubule comes into intimate contact with the afferent and efferent arterioles of the same nephron.
B) It secretes aldosterone.
C) It secretes renin.

Question 59

What stimulates sodium reabsorption in the distal portions of the nephron?

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

Question 60

Which statement regarding the juxtaglomerular apparatus is NOT true?

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 61

Which statement regarding water reabsorption is NOT true?

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.

Question 62

Which statement concerning the medullary vertical osmotic gradient is INCORRECT?

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 1,200 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 63

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 which?

A) secreted and reabsorbed by the tubules.
B) neither reabsorbed nor secreted by the tubules.
C) secreted by the tubules.
D) reabsorbed by the tubules.

Question 64

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 65

What happens to the 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 66

Which statement with regards to plasma clearance is correct?

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

Question 67

Which statement regarding tubular secretion is NOT true?

A) It involves transepithelial transport.
B) It is the movement of a substance from the peritubular capillary blood into the tubular fluid.
C) It always occurs by active transport.
D) a and b.

Question 68

Which of the following does NOT stimulate(s)aldosterone secretion?

A) an increase in plasma K+
B) a decrease in plasma K+
C) activation of the renin-angiotensin pathway

Question 69

Which statement is NOT true for 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 urea 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.

Question 70

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 71

Which statement regarding urea is NOT true?

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 72

Which statement regarding tubular secretion is correct?

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) Tubular secretion of K+ occurs in proximal convoluted tubules and is stimulated by aldosterone.

Question 73

Which statement with regards to inulin is correct?

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 74

Why is tubular secretion 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) for glucose secretion.

Question 75

What are the distal and collecting tubules the site of?

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

Question 76

Which statement concerning water reabsorption is correct?

A) Water reabsorption is under 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 77

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 78

Which statement regarding water reabsorption is NOT true?

A) It cannot occur from any portion of the nephron in the absence of vasopressin.
B) It occurs to the greatest extent in the proximal convoluted tubule.
C) It is under vasopressin control in the distal and collecting tubules.

Question 79

Which substance is NOT normally secreted into the tubule?

A) hydrogen ions
B) potassium ions
C) glucose

Question 80

Which statement is NOT true for 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.