Physiology I Exam 3 Flashcards by Adam Sklamberg

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?

Release of renin by the juxtaglomerular apparatus
Release of endothelin by the glomerular capillaries
Release of nitric oxide by the vasa recta endothelium
Release of angiotensin2 by the juxtaglomerular apparatus

Release of renin by the juxtaglomerular apparatus

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

Glomerular capillary colloid osmotic pressure
Bowman’s capsule hydrostatic pressure
Bowman’s capsule colloid osmotic pressure
Glomerular hydrostatic pressure

Glomerular hydrostatic pressure

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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?

Urine would contain numerous red blood cells
Urine would contain excess albumin
Urine would contain excess sodium and chloride
Urine would be less concentrated

Urine would contain excess albumin

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

Bradykinin
Angiotensin 2
Endothelial-derived nitric oxide
Endothelin

Angiotensin 2

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What is, in L/day, represents the GFR in the average adult human?

3
125
180
360

180 L/day

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

Arterial pressure
Afferent arteriole resistance
Efferent arteriole resistance
Both B and C
All of the above

Afferent arteriole resistance

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

25%
50%
75%
100%

25%

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

Sodium
Water
Urea
Amino Acids

Water

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

Podocytes
Principle cells
Intercalated cells
Cells of macula densa

Principle cells

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Most potassium reabsorption occurs at which of the following sites?

Ascending Loop of Henle
Distal convoluted tubule
Proximal convoluted tubule
Collecting duct

Proximal convoluted tubule

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

Descending limb of Henle
Ascending limb of Henle
Late distal tubules in the intercalated cells
Early collecting tubules in principle cells

Late distal tubules in intercalated cells.

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

Adrenal cortex
Adrenal medulla
Anterior pituitary
Posterior pituitary

Posterior pituitary

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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?

0 L/day
5 L/day
3 L/day
0 L/day

0.5 L/day

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ADH acts on what region of the nephron?

Proximal convoluted Tubule
Descending Loop of Henle
Ascending Loop of Henle
Distal Convoluted tubule

Distal convoluted tubule

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

180 liters
75 liters
20 liters
4 liters

20 liters

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

6000-7000 mOsm/L
5500-6000 mOsm/L
1200-1400 mOsm/L
2000-2400 mOsm/L

1200-1400 mOsm/L

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Osmoreceptor cells are located in which of the following regions?

Adjacent to carotid bodies
In the macula densa
In the anterior part of the third ventricle
In the distal collecting ducts

In the anterior part of the third ventricle

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What segment of the nephron is NOT permeable to water?

Proximal Convoulted tubule in the presence of ADH
Descending Loop of Henle in the presence of ADH
Ascending Loop of Henle in the presence of ADH
Distal Convoluted Tubule in the presence of ADH

Ascending Loop of Henle in the presence of ADH

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

Aldosterone
Angiotensin II
Sodium ion
PTH

Aldosterone

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

1%
47%
78%
99%

99%

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How much of filtered calcium is excreted by the kidneys?

1%
47%
78%
99%

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Which of the following cells reabsorbs potassium during potassium depletion?

Intercalated cells
Principle cells
Chief cells
Podocytes

Intercalated cells

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

Potassium excretion would increase with increased tubular flow rate
Potassium excretion would decrease with increased tubular flow rate
There would be little effect
Tubular flow rate would be decreased

Potassium excretion would increase with increased tubular flow rate

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

Metabolic acidosis decreases extracellular K+ concentration
Metabolic alkalosis increases extracellular K+ concentration
Metabolic acidosis increases extracellular K+ concentration
Both A and B are valid

Metabolic acidosis increases extracellular K+ concentration

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Which of the following buffer systems is most important in buffering renal tubular fluid? Phosphate buffer system Carbonate buffer system Bicarbonate buffer system Hemoglobin buffer system

Phosphate buffer system

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

Weak acids

The bicarbonate buffer system consists of a bicarbonate salt and which of the following? Weak acid Strong acid Weak base Strong base

Weak acid

Which of the following buffer systems is the most important extracellular buffer system? Phosphate buffer system Carbonate buffer system Bicarbonate buffer system Hemoglobin buffer system

Bicarbonate buffer system

Most bicarbonate reabsorption occurs in which of the following parts of the renal tubule? Proximal tubule Descending limb of Henle Ascending limb of Henle Distal tubule

Proximal tubule

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

Metabolic acidosis

Respiratory alkalosis due to decrease in carbon dioxide concentration caused by hyperventilation is compensated for by which of the following mechanisms? Increased ventilation rate Decreased ventilation rate Renal excretion of bicarbonate ion Renal addition of new bicarbonate ion to extracellular fluid

Renal excretion of bicarbonate ion

Which of the following would be a result of increased levels of angiotensin II? Decreased blood pressure Increased vasoconstriction Increased natriuresis Decreased aldosterone levels

Increased vasoconstriction

A 1-sodium, 2-chloride, 1-potassium co-transporter is found in the luminal membrane of which part of the renal tubule? Proximal convoluted tubule Thin descending limb of Henle Thick ascending limb of Henle Distal convoluted tubule

Thick ascending limb of Henle

If tidal volume is 0.5 liters, dead space is 0.15 liters, and breathing rate is 12 times per minute, What is the minute ventilation? 1. 8 liters 4. 0 liters 6. 0 liters 7. 8 liters

6.0 liters

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? Henry's Boyle's Dalton's Euclid's

Henry's

If tidal volume is 0.5 liters, dead space is 0.15 liters and breathing rate is 12 times per minute; what is the minute alveolar or alveolar ventilation? 1. 8 liters 3. 5 liters 4. 2 liters 6. 0 liters

4.2 liters

Humidification of the air in the alveoli had which of the following effects on the partial pressures of nitrogen and oxygen in the alveoli? It increases the partial pressure of each of the other gases It decreases the partial pressure of each of the other gases It has no effect on the partial pressures of each of the other gases It increases the partial pressure of oxygen but decreases the partial pressure of nitrogen in alveolar air

It decreases the partial pressures of each of the other gases.

The range in the pressure change (in cm of water) in alveolar pressure during inspiration is expressed by which of the following? 0 to -1 - 5 to -7.5 - 7.5 to -5 - 1 to 0

0 to -1

What would be the Va/Q ratio for alveolar air with a PO2 of 104 and PCO2 of 40? 2.5 0.8 0 Infinity

0.8

Which of the following characteristics of alveoli lacker perfusion, as in the case of a pulmonary embolism? Va/Q ratio = infinity Va/Q = 0 Blood gas composition remains unchanged Both A and C are characteristics

Va/Q ratio = infinity

Under normal conditions at rest, which of the following patterns regarding pulmonary blood flow would be most likely? Apices: zone 1; middle part of the lungs: zone 1; lower part of the lungs: zone 3 Apices: zone 2; middle part of the lungs: zone 2; lower part of the lungs: zone 3 Apices: zone 2; middle part of the lungs: zone 3; lower part of the lungs: zone 3 Apices: zone 1; middle part of the lungs: zone 2; lower part of the lungs: zone 1

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

The pulmonary circulation can be divided into two systems. Which of the following describes the system supplying the trachea, bronchia; tree, and rest of the intersititum? High pressure - low flow High pressure - high flow Low pressure - low flow Low pressure - high flow

High pressure - low flow

Which of the following represents the mean pulmonary arterial pressure in mmHg? 7 15 25 125

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? 7 mmHg 15 mmHg 20 mmHg 25 mmHg

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 approx. volume of urine required to be excreted if all the excess H+ remained free in solution? 1.5 L/day 180 L/day 2700 L/day 4500 L/day

2700 L/day

Which of the following are sensory endings (C fibers) in the alveolar wall next to pulmonary caps that are sensitive to pulmonary edema? Slow adapting pulmonary stretch receptors Rapidly adapting pulmonary stretch receptors J receptors Hering Breuer receptors

J receptors (juxtapositional receptors)

Which of the following represents the oxygen utilization coefficient at rest? 15% 25% 50% 75%

25%

What is the lowest limit of pH that can be achieved in the normal kidney? 6. 5 5. 0 4. 5 2. 5

4.5

Which of the following factors decreases potassium uptake by cells? Aldosterone Metabolic acids Insulin Catecholamines

Metabolic acids

A hydrogen transporting ATPase is first encountered in which of the following parts of the renal tubule? Proximal convoluted tubule Descending limb of Henle Ascending limb of Henle Distal convoluted tubule

Distal convoluted tubule

Normally, how much hydrogen ion must be secreted each day in order to reabsorb 4320 mEq of filtered Bicarbonate? 2160 mEq 4320 mEq 8640 mEq The two processes are independent of one another

4320 mEq

Decreased concentration of calcium ion in the plasma would have a direct effect on which of the following? Activation of vitamin D3 Increase in intestinal calcium ion reabsorption Increase in release of PTH Release of calcium ion on bones

Increase in release of PTH. everything else would be indirect!

In a normal individual, which of the following represents the transport max for glucose? 125 mg/min 250 375 500

375 mg/min

Which of the following represent a substance that is actively secreted into the renal tubules? Urea Angiotensin2 Creatine ADP

Creatine

Which of the following best describes the capillary filtration coefficient? Average diameters of the glomerular caps Mean of the cap pressure w/in the glomerulus Product of the permeability and filtering surface area of the glomerular capillaries Mean of the hydrostatic pressure within the glomerular capillaries

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

Which of the following is a vasodilator that may help to offset the effects of vasoconstrictors on the afferent arterioles? Bradykinin Endothelin Angiotensin2 Norepinephrine

Bradykinin

Much of the o2 consumed by the kidneys is related to which of the following factors? High rate of glucose reabsorption High rate of active sodium reabsorption High rate of active potassium reabsorption High rate of active amino acid reabsorption

High rate of active sodium reabsorption

Which of the following is responsible for partially inhibiting micturition except when micturition is desired? Parasympathetic system Sympathetic system Pudendal nerves Pelvis splanchnic nerves

Pudendal nerves

W/out autoregulation, a slight increase in BP could increase GFR to 225L/day. How much would this increase urine flow (excretion)? 20.0 L/day 32.7 46.5 180

46.5 L/day (45+ because normal is 1.5)

What is the partial pressure of o2 in mmHg at the alveolar mem if the percentage of oxygen in the alveoli is 20%? 75 122 152 266

152

Using the Flick principle for calculating the CO, the patient's resting O2 consumption volume should be divided by which of the following? The difference between the oxygen concentration in the systemic arterial blood and the systemic mixed venous blood The difference between the oxygen concentration in the systemic arterial blood and the pulmonary vein The difference between the oxygen concentration in the systemic mixed venous blood and the pulmonary vein The difference between the oxygen concentration in the systemic mixed venous blood and the pulmonary artery

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

What is the GFR if the urine concentration rate of a substance is 125 mg/mL; the flow rate is 2 ml/min, and plasma concentration of the substance is 1? 10 25 125 250

250

Almost 90% of glucose reabsorption occurs in the early proximal tubule. Which of the following mechanism is responsible for moving glucose from the tubular lumen into the cytoplasmic compartment? Primary active transport via a glucose ATPase pump Secondary active transport via sodium/glucose co-transporter Secondary active transport via a sodium/glucose antiporter Diffusion due to concentration differences between tubular fluid and cytoplasm

Secondary active transport via sodium/glucose co-transporter

A 24 yr old woman presents to the emergency department with severe diarrhea. When she is supine, her BP is 90/60 and 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? Decreased total peripheral resistance Increased vasoconstriction Increased after load Decreased venous return

Decreased venous return

Which of the following factors results in hypokalemia? Cell lysis Excess secretion of aldosterone Strenuous exercise Increased extracellular fluid osmolarity

Excess secretion of aldosterone

An increase in which of the following factors will result in a decrease in glomerular hydrostatic pressure? ``` Arterial pressure Afferent arteriole resistance Efferent arteriole resistance B and C All of above ```

Afferent arteriole resistance

Which of the following centers acts to control the "switch off" point of the inspiratory ramp signal? Dorsal respiratory group Pneumotaxic center Ventral respiratory group Aortic body

Pneumotaxic center

ADH is formed in the supraoptic and paraventricular nuclei. It is secreted by specialized neurons from which of the following areas? Adrenal cortex Adrenal medulla Anterior pituitary Posterior pituitary

Posterior pituitary

ADH acts on which of the following regions of the nephron? Proximal convoluted tubule Descending loop of Henle Ascending loop of Henle Distal convoluted tubule

Distal convoluted tubule

Which of the following reflects the amount of urine that the kidneys can excrete per day when there is a large excess of water? 180 L 75 20 4

20 L

Because of paracellular diffusion of ions back into the tubule, what is the upper limit of the concentration gradient created by the countercurrent multiplier mech? 1200 mOsm/L 600 400 200

200 mOsm/L

Osmoreceptor cells are located in which of the following regions? Adjacent to the carotid bodies In the macula dense In the anterior part of the third ventricle In the distal collecting ducts

In the anterior part of the third ventricle

Which of the following would NOT shift the Oxygen-hemoglobin curve to the right and downward? A decrease in pH An increase in CO2 An increase in temperature A decrease in BPG

A decrease in BPG

What percentage of CO2 is carried in the blood as bicarbonate? 5% 25 30 70

70%

Which respiratory control center is primarily responsible for establishing the ramp signal during normal breathing? Dorsal respiratory group Pneumotaxic center Ventral respiratory group Carotid body

Dorsal respiratory group

What is the source of the hormone aldosterone? Juxtaglomerular cells Principle cells Adrenal cortex Liver

Adrenal cortex

Magnesium and calcium are reabsorbed from the tubular lumen through which of the following mechanisms? Antiport with sodium ions Active transport via transporters in basal mem Paracellular transport due to positive charge in tubular lumen Paracellular transport due to negative charge in interstitium

Paracellular transport due to positive charge in tubular lumen

Shrinkage of osmoreceptor cells in the anterior hypothalamus in response to an increase in extracellular fluid osmolarity leads to the release of which of the following? Aldosterone Angiotensin1 Angiotensin2 ADH

ADH

True or false: Chemoreceptors associated with respiratory functions increase their rate of activity when hypoxia or hypercapnia occur.

True

Most of the filtered electrolytes are reabsorbed in which of the following regions of the kidney tubule? Proximal convoluted tubule Descending loop of Henle Ascending loop of Henle Early collecting duct

Proximal convoluted tubule

The lower pH of the tubular fluid brings the operating range of the buffer closer to the pK of which of the following systems? Bicarbonate Phosphate Carbonic acid Proteins

Phosphate

Which of the following would NOT be true regarding the Haldane effect? Binding of O2 with Hb displaces CO2 from blood Binding of O2 causes Hb to become a stronger acid Increased acidity of Hb causes it to release hydrogen ions O2-Hb dissociation curve shifts to the right

O2-Hb dissociation curve shifts to the right

Which of the following must happen before filtered bicarb can be reabsorbed? Kidneys must secrete new bicarb Kidneys must reabsorb H+ ions Kidneys must secret carbonic anhydrase Filtered bicarb must react with secreted hydrogen ion to form carbonic acid

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

Which of the following segments of the nephron is NOT permeable to water? Proximal convoluted tubule in the presence of ADH Descending loop of Henle in the presence of ADH Ascending loop of Henle in the presence of ADH Distal convoluted tubule in the presence of ADH

Ascending loop of Henle int he presence of ADH

The macula densa is found in which of the following parts of the renal tubule? Proximal convoluted tubule Thin descending limb of Henle Thick ascending limb of Henle Distal Convoluted Tubule

Distal Convoluted Tubule

Which of the following cells play a major role in the secretion of potassium? Intercalated Cells Principal Cells Chief Cells Podocytes

Principal Cells

Physiology I Exam 3 Flashcards

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