PHYS 3

Question 1

High potassium intake greatly increases the potassium secretion rate even at low tubular flow rates. Which of the following best describes the effect of high sodium intake on potassium secretion rate by the kidneys?

Answer 1

High sodium intake has little effect on potassium secretion

Question 2

About 80 Meq of nonvolatile acid is formed by metabolism per day. The minimal urine hydrogen ion concentration is about 0.03 mEq/L What would be the approximate volume of urine required to be excreted if all of the excess hydrogen ions remained free in solution?

Answer 2

2700 L 80/0.03

Question 3

Which of the following are sensory endings (C fibers) in the alveolar wall next to pulmonary capillaries that are sensitive to pulmonary edema?

Answer 3

J receptors

Question 4

Which of the following represents the oxygen utilization coefficient at rest?

Answer 4

25%

Question 5

Which of the following factors decreases potassium uptake by cells?

Answer 5

Metabolic acidosis

Question 6

A hydrogen-transporting ATPase is first encountered in which of the following parts of the renal tubules?

Answer 6

Distal convoluted tubule

Question 7

Normally, how much hydrogen ion must be secreted each day in order to reabsorb 4320 mEq of filtered bicarbonate?

Answer 7

4320 mEq

Question 8

Decreased concentration of calcium ion in the plasma would have a direct effect on which of the following?

Answer 8

Increased in release of parathyroid hormone

Question 9

In a normal individual, which of the following represents the maximum transport for glucose?

Answer 9

375 mg/min

Question 10

Which of the following represents a substance that is actively secreted into the renal tubules?

Answer 10

Creatinine

Question 11

Which is the lowest limit of pH that can be achieved in the normal kidney?

Answer 11

4.5

Question 12

Which of the following best describes the capillary filtration coefficient?

Answer 12

Product of the permeability and filtering surface area if the glomerular capillaries

Question 13

Which of the following is a vasodilator that may help to offset the effects of vasoconstrictors, especially on afferent arterioles?

Answer 13

bradykinin

Question 14

Much of the oxygen consumed by the kidneys is related to which of the following factors?

Answer 14

high rate of active sodium reabsorption

Question 15

Which of the following is responsible for partially inhibiting micturition except when micturition is desired?

Answer 15

pudendal nerves

Question 16

Without autoregulation, a slight increase in blood pressure could increase GFR up to 225 L/day. How much would this increase urine flow (excretion) ?

Answer 16

46.5 L/day normal urine output is 1.5 45+1.5

Question 17

What is the partial pressure of oxygen in mmHg at the alveolar membrane if the percentage of oxygen in the alveoli is 20 percent?

Answer 17

152

Question 18

Using the Flick principle for calculating the cardiac output, the patient’s resting oxygen consumption volume should be divided by which of the following?

Answer 18

The difference between oxygen concentration in the systematic arterial blood and the systemic mixed venous blood

Question 19

What is the glomerular filtration rate if the urine concentration rate of a substance is 125; the flow rate is 2 ml/min; and the plasma concentration of the substance is 1 mg/ml?

Answer 19

250

Question 20

Almost 90 percent of glucose reabsorption occurs in the early proximal tubule. Which of the following mechanisms is responsible for moving glucose from the tubular lumen into the cytoplasmic compartment?

Answer 20

Secondary active transport via a sodium/glucose cotransporter

Question 21

A 24 yr old woman presents to the ED with severe diarrhea. When she is supine, her blood pressure is 90/60 and her heart rate is 100 bpm. When she is moved to a standing position, her heart rate increases to 120 bpm. Which of the following accounts for the further increase in heart rate upon standing?

Answer 21

decreased venous return

Question 22

which of the following factors results in hypokalemia?

Answer 22

excess secretion of aldosterone

Question 23

an increase in which of the following factors will result in a decrease in flomerular hydrostatic pressure?

Answer 23

afferent arteriolar pressure

Question 24

which of the following centers acts to control the switch off point of the inspiratory ramp signal?

Answer 24

pneumotaxic center

Question 25

ADH (antidiuretic hormone) is formed in the supraoptic and paraventricular nuclei. It is secreted by specialized neurons from which of the following areas?

Answer 25

Posterior pituitary

Question 26

A normal 70 kg human must excrete about 600 mosm of solute each day in order to get rid of waste products of metabolism and ions that are ingested. The maximal urine concentrating ability is 1200. Which of the following represents the obligatory urine volume that must be excreted each day to get rid of metabolic waste products.

Answer 26

0.5 L/day

Question 27

ADH acts on which of the following regions of the nephron?

Answer 27

distal convoluted tubule

Question 28

which of the following reflects the amount of urine that the kidneys can excrete per day when there is a large excess of water?

Answer 28

20

Question 29

Which of the following reflects the maximum urine concentration that can be produced by the kidneys?

Answer 29

1200-1400 mOsml/L

Question 30

Because of paracellular diffusion of ions back into the tubule, what is the upper liit of the concentration gradient created by the countercurrent multiplier mechanism?

Answer 30

200

Question 31

Osmoreceptor cells are located in which of the following regions?

Answer 31

in the anterior part of the third ventricle

Question 32

Which of the following would NOT shift the oxygen-hemoglobin curve to the right and downward?

Answer 32

A decrease in BPG (bi-phosphoglycerate)

Question 33

What percentage of carbon dioxide is carried in the blood as bicarbonate?

Answer 33

70%

Question 34

Which respiratory control center is primarily responsible for establishing the ramp signal during normal breathing?

Answer 34

dorsal respiratory group

Question 35

What is the source of the hormone aldosterone?

Answer 35

adrenal cortex

Question 36

Magnesium and calcium are reabsorbed from the tubular lumen thought which of the following mechanisms

Answer 36

paracellular transport due to positive charge in tubular lumen

Question 37

Shrinkage of osmoreceptor cells in the anterior hypothalamus in response to an increase in the extracellular fluid osmolarity leads to the release of which of the following?

Answer 37

ADH

Question 38

Chemoreceptors associated with which of the respiratory functions increase their rate of activity when hypoxia or hypercapnia occur?

Answer 38

TRUE

Question 39

Most of the filtered electrolytes are reabsorbed in which of the following regions of the kidney tubules

Answer 39

proximal convoluted tubule

Question 40

The lower pH of the tubular fluid brings the operating range of the buffer closer to the pK of which of the following systems?

Answer 40

phosphate

Question 41

Which of the following would NOT be true regarding the Haldane effect?

Answer 41

Oxygen-hemoglobin dissociation curve shifts to the right

Question 42

Which of the following must happen before filtered bicarbonate can be reabsorbed

Answer 42

Filtered bicarbonate must react with secreted hydrogen ion to form carbonic acid

Question 43

Which of the following segments of the nephron is NOT permeable to water?

Answer 43

Ascending loop of Henle in the presence of ADH

Question 44

Renal autoregulation refers to the relative constancy of GFR and renal blood flow. A decrease in arterial pressure and glomerular filtration rate ultimately leads to a reduction in the concentration of sodium ions at the macula densa. This results in which of the following responses that ultimately restores GFR?

Answer 44

Release of renin by the juxtaglomerular apparatus

Question 45

GFR is determined by the net filtration pressure and the glomerular capillary filtration coefficient. Which of the following factors has the greatest effect on increased GFR? Glomerular capillary colloid osmotic pressure

Answer 45

glomerular hydrostatic pressure

Question 46

Minimum change disease occurs when the negative charges on the filtration membrane of the glomerulus are not present. What abnormality in the urine would be expected under these conditions?

Answer 46

Urine would contain excess albumin

Question 47

A number of hormones are involved in the control of glomerular filtration rate. Which of the following preferentially constricts the efferent arterioles but has little to no effect on the afferent arterioles?

Answer 47

angiotensin II

Question 48

Which of the following, in liters/day, represents the GFR in the average adult human?

Answer 48

180

Question 49

An increase in which of the following factors will result in a decrease in glomerular hydrostatic pressure?

Answer 49

afferent arteriolar resistance

Question 50

Approximately how much of the total cardiac output is received by the kidneys?

Answer 50

25% (last test)

Question 51

The macula densa is found in which of the following parts of the renal tubule?

Answer 51

distal convoluted tutbule

Question 52

Which of the following properties is a measure of the ease with which a hollow viscus may be distended?

Answer 52

Compliance (last exam)

Question 53

ADH (anti-diuretic hormone) is formed in the supraoptic and paraventricular nuclei. It is secreted by specialized neurons from which of the following areas?

Answer 53

Posterior pituitary

Question 54

The thin descending loop of henle is highly permeable to which of the following?

Answer 54

water

Question 55

Aldosterone is an important regulator of sodium reabsorption and potassium secretion; one of its main targets is what?

Answer 55

principal cells

Question 56

Which of the following cells play a major role in the secretion of potassium?

Answer 56

Proximal convoluted tubule

Question 57

Primary active hydrogen secretion involves a hydrogen-transporting ATPase. It occurs in which of the following parts of the renal tubules?

Answer 57

Late distal tubules in intercalated cells

Question 58

Which portion of the renal tubules is the primary site of K+ sparing diuretics?

Answer 58

Late distal tubule

Question 59

A normal 70 kg human must excrete about 600 mOsm of solute each day in order to get rid of waste products of metabolism and ions that are ingested. The maximal urine concentrating ability is 1200 mOsm/L. Which of the following represents the obligatory urine volume that must be excreted each day to get rid of metabolic waste products?

Answer 59

0.5L/day

Question 60

ADH acts on which of the following regions of the nephron?

Answer 60

distal convoluted tubule

Question 61

Which of the following reflects the amount of urine that the kidneys can excrete per day when there is a large excess of water?

Answer 61

20L

Question 62

Which of the following reflects the maximum urine concentration that can be produced by the kidneys?

Answer 62

1200-1400 mOsml/L

Question 63

Osmoreceptor cells are located in which of the following regions?

Answer 63

In the anterior part of the third ventricle

Question 64

Which of the following segments of the nephron is NOT permeable to water?

Answer 64

Ascending loop of Henle in the presence of ADH

Question 65

Where in the kidney tubules are most of the filtered electrolytes reabsorbed?

Answer 65

Proximal tubule

Question 66

ADH is formed in which of the following regions?

Answer 66

Supraoptic nuclei, and paraventricular nuclei

Question 67

Which of the following plays a major role in stimulating potassium excretion by the kidney tubules?

Answer 67

Aldosterone

Question 68

Approximately how much of the body's supply of calcium is stored in bone?

Answer 68

99%

Question 69

How much of filtered calcium is excreted by the kidneys?

Answer 69

1%

Question 70

Which of the following cells reabsorb potassium during potassium depletion?

Answer 70

Intercalated cells

Question 71

A high potassium intake would have which of the following effects on potassium excretion associated with increased renal tubular flow rate?

Answer 71

Potassium excretion would increase with increased tubular flow rate

Question 72

Which of the following describes a valid change in potassium distribution de to an acid-base abnormality?

Answer 72

Metabolic acidosis increases extracellular K+ concentration

Question 73

Which of the following buffer systems is most important in buffering renal tubular fluid?

Answer 73

phosphate buffer system

Question 74

Compounds that dissociate incompletely into hydrogen ions and a conjugate base are members of which of the following compounds?

Answer 74

weak acids

Question 75

The bicarbonate buffer system consists of a bicarbonate salt and which of the following?

Answer 75

weak acid (H2CO3)

Question 76

Which of the following buffer system is the most important extracellular buffer system?

Answer 76

bicarbonate buffer system

Question 77

Most bicarbonate reabsorption occurs in which of the following parts of the renal tubule?

Answer 77

proximal tubule

Question 78

Which of the following occurs when a decrease in a bicarbonate ion results in a decrease in the ratio of bicarbonate ion to carbon dioxide in the extracellular fluid?

Answer 78

Metabolic acidosis

Question 79

Respiratory alkalosis due to a decrease in carbon dioxide concentration caused by hyperventilation is compensated for by which of the following mechanisms?

Answer 79

Renal excretion of bicarbonate ion

Question 80

Which of the following would be a result of increased levels of angiotensin II

Answer 80

increased vasoconstriction

Question 81

A 1-sodium, 2-chloride, 1-potassium co-transporter is found in the luminal membrane of which part of the renal tubule?

Answer 81

Thick ascending limb of Henle

Question 82

Which of the following are important in allowing larger amounts of hydrogen ions to be excreted?

Answer 82

Phosphate, and ammonia buffer system

Question 83

If tidal volume is 0.5 L, dead space is 0.15 L, and breathing rate is 12 times per minute, calculate the minute ventilation

Answer 83

6.0 L

Question 84

The solubility of oxygen =0.024; the solubility of carbon dioxide = 0.57. Because carbon dioxide is more soluble in water than oxygen, it will exert a partial pressure (for a given concentration) that is less than 1/20th that of oxygen. This relationship between partial pressures and solubility illustrates which of the following gas laws?

Answer 84

Henry's

Question 85

If tidal volume is 0.5 L, dead space is 0.15 L, and breathing rate is 12 times per minute; calculate the minute alveolar ventilation.

Answer 85

4.2 L

Question 86

Humidification of air in the alveoli has which of the following effects on the partial pressure of nitrogen and oxygen in the alveoli?

Answer 86

It decreases the partial pressure of each of the other gases

Question 87

The range in the pressure change (in cm of water) in alveolar pressure during inspiration is expressed by which of the following?

Answer 87

0 to -1

Question 88

What would the Va/Q ratio for alveolar air with a PO2 of 104 and a PCO2 of 40?

Answer 88

0.8

Question 89

Which of the following would be characteristic of alveoli lacking perfusion, as in the case of pulmonary embolism?

Answer 89

Va/Q ratio = infinity

Question 90

Under normal conditions at rest, which of the following patterns regarding pulmonary blood flow would be most likely?

Answer 90

Apices: zone 2; middle part of lungs: zone 3; lower part of lungs: zone 3

Question 91

The pulmonary circulation can be divided into two systems. Which of the following best describes the system supplying the trachea, bronchial tree, and rest of the interstitium?

Answer 91

High pressure - low flow

Question 92

Which of the following represents the mean pulmonary arterial pressure in mmHg?

Answer 92

15

Question 93

The most common cause of pulmonary edema is left sided heart failure or mitral valve disease. Pulmonary edema occurs when pulmonary capillary pressure exceeds which of the following levels?

Answer 93

25 mmHg

Question 94

The pulmonary circulation can be divided into two systems. Which of the following best describes the system supplying the pulmonary artery branches and the alveoli?

Answer 94

Low pressure - high flow

Question 95

During exercise, which of the following patterns regarding pulmonary blood flow would be most likely?

Answer 95

Apices: zone 3; middle part of lungs: zone 3; lower part of longs: zone 3