Systems physiology final HW questions
Which of the following would likely lead to hyponatremia? A) Excessive ADH secretion B) Restriction of fluid intake C) Excess aldosterone secretion D) Administration of 2 liters of 3% NaCl solution E) Administration of 2 liters of 0.9% NaCl solution
a
Which part of the nephron normally reabsorbs the most water? A) A B) B C) C D) D E) E
a
exposure to ultraviolet light directly facilitates which of the following? A) Conversion of cholesterol to 25-hydroxycholical- ciferol B) Conversion of 25-hydroxycholicalciferol to 1,25- dihydroxycholicalciferol C) Transport of calcium into the extracellular fluid D) Formation of calcium-binding protein E) storage of vitamin d3 in the liver
a
f a person has been exercising for 1 hour, which organ will have the smallest decrease in blood flow? a.Brain b.Intestines c.Kidneys d.Non-Exercising skeletal muscle e.Pancreas
a
A 48-year-old woman reports severe polyuria (produc- ing about 0.5 liter of urine each hour) and polydipsia (drinking two to three glasses of water every hour). Her urine contains no glucose, and she is placed on overnight water restriction for further evaluation. The next morn- ing, she is weak and confused, her sodium concentration is 160 mEq/L, and her urine osmolarity is 80 mOsm/L. Which of the following is the most likely diagnosis? A) Diabetes mellitus B) Diabetes insipidus C) Primary aldosteronism D) Renin-secreting tumor E) Syndrome of inappropriate ADH
b
A 50-year old woman has a renal blood flow of 1200 ml/min and a hematocrit of 50 Her arterial pressure is 125 mm Hg, and her renal venous pressure is 5 mm Hg. She also has a plasma colloid osmotic pressure of 25 mm Hg and a glomerular capillary hydrostatic pressure of 50 mm Hg. What is the total renal vascular resistance (in mm Hg/ml/min) in this woman? a.0.05 b.0.10 c.0.50 d.1 e.1.5
b
A sustained program of lifting heavy weights will in- crease bone mass. What is the mechanism of this effect of weightlifting? A) Elevated metabolic activity stimulates parathyroid hormone secretion B) Mechanical stress on the bones increases the activity of osteoblasts C) Elevated metabolic activity results in an increase in dietary calcium intake D) Elevated metabolic activity results in stimulation of calcitonin secretion
b
An adrenal tumor that causes excess aldosterone secre- tion would tend to __________ plasma K+ concentration, __________ plasma pH, __________ renin secretion, and __________ blood pressure. A) Decrease, decrease, decrease, decrease B) Decrease, increase, decrease, increase C) Decrease, decrease, decrease, increase D) Decrease, increase, increase, increase E) Increase, increase, decrease, increase F) Increase, decrease, decrease, increase
b
An increase in which of the following tends to decrease capillary filtration rate? A) Capillary hydrostatic pressure B) Plasma colloid osmotic pressure C) Interstitial colloid osmotic pressure D) Venous hydrostatic pressure E) Arteriolar diameter
b
At a fraternity party, a 17 year old male places a paper bag over his mouth and breathes in and out of the bag. As he continues to breathe into this bag, his rate of breathing continues to increase. Which of the following is responsible for the increased ventilation? a.Increased alveolar PO2 b.Increased Alveolar PCO2 c.Decreased Arterial PCO2 d.Increased pH
b
Listed below are the hydrostatic and oncotic pressures within a microcirculatory bed. Plasma colloid osmotic pressure = 25 mm Hg Capillary hydrostatic pressure = 25 mm Hg Venous hydrostatic pressure = 5 mm Hg Arterial pressure = 80 mm Hg Interstitial hydrostatic pressure = −5 mm Hg Interstitial colloid osmotic pressure = 5 mm Hg Filtration coefficient = 15 ml/min/mm Hg What is the filtration rate (ml/min) of the capillary wall? A) 100 B) 150 C) 200 D) 250 E) 300
b
The diffusing capacity of a gas is the volume of gas that will diffuse through a membrane each minute for a pressure difference of 1 mm Hg. Which gas is often used to estimate the O2-diffusing capacity of the lungs? A) CO2 B) CO C) Cyanide gas D) Nitrogen E) O2
b
Under conditions of normal renal function, what is true of the concentration of urea in tubular fluid at the end of the proximal tubule? A) It is higher than the concentration of urea in tubu- lar fluid at the tip of the loop of Henle B) It is higher than the concentration of urea in the plasma C) It is higher than the concentration of urea in the final urine in antidiuresis D) It is lower than plasmaure Concentration Because Of active urea reabsorption along the proximal tubule
b
Under conditions of normal renal function, what is true of the concentration of urea in tubular fluid at the end of the proximal tubule? A) It is higher than the concentration of urea in tubular fluid at the tip of the loop of Henle B) It is higher than the concentration of urea in the plasma C) It is higher than the concentration of urea in the final urine in antidiuresis D) It is lower than plasma urea Concentration Because Of active urea reabsorption along the proximal tubule
b
Using the following data, calculate the filtration coefficient for the capillary bed. Plasma colloid osmotic pressure = 30 mm Hg Capillary hydrostatic pressure = 40 mm Hg Interstitial hydrostatic pressure = 5 mm Hg Interstitial colloid osmotic pressure = 5 mm Hg Filtration rate = 150 ml/min Venous hydrostatic pressure = 10 mm Hg A) 10 ml/min/mm Hg B) 15 ml/min/mm Hg C) 20 ml/min/mm Hg D) 25 ml/min/mm Hg E) 30 ml/min/mm Hg
b
What happens during exercise? A) Blood flow is uniform throughout the lung B) Lung-diffusing capacity increases because blood flow is continuous in all pulmonary capillaries C) Pulmonary blood volume decreases D) The transit time of blood in the pulmonary capillaries does not change from rest
b
What tends to decrease airway resistance? a.Asthma b.Stimulation by sympathetic fibers c.Treatment with acetylcholine d.Exhalation to residual volume
b
What would cause the greatest degree of hyperkalemia? A) Increase in potassium intake from 60 to 180 mmol/day in a person with normal kidneys and a normal aldosterone system B) Chronic treatment with a diuretic that inhibits the action of aldosterone C) Decrease in sodium intake from 200 to 100 mmol/ day D) Chronic treatment with a diuretic that inhibits loop of Henle Na+-2Cl−-K+ co-transport E) Chronic treatment with a diuretic that inhibits so- dium reabsorption in the collecting ducts
b
Which of the following is true of the tubular fluid that passes through the lumen of the early distal tubule in the region of the macula densa? A) It is usually isotonic B) It is usually hypotonic C) It is usually hypertonic D) It is hypertonic in antidiuresis E) It is hypertonic when the filtration rate of its own nephron decreases to 50% below normal
b
Which of the following tends to increase the net movement of glucose across a capillary wall? A) Increase in plasma sodium concentration B) Increase in the concentration difference of glucose across the wall C) Decrease in wall permeability to glucose D) Decrease in wall surface area without an increase in the number of pores E) Decrease in plasma potassium concentration
b
Which of the following would have the slowest rate of net movement across the capillary wall? A) Sodium B) Albumin C) Glucose D) Oxygen
b
in normal kidneys, which of the following is true of the osmolarity of renal tubular fluid that flows through the early distal tubule in the region of the macula densa? A) Usually isotonic compared with plasma B) Usually hypotonic compared with plasma C) Usually hypertonic compared with plasma D) Hypertonic, compared with plasma, in antidiuresis
b
A decrease in which of the following tends to increase lymph flow? A) Capillary hydrostatic pressure B) Interstitial hydrostatic pressure C) Plasma colloid osmotic pressure D) Lymphatic pump activity E) Arteriolar diameter
c
A decrease in which of the following tends to increase pulse pressure? a.Systolic pressure b.stroke volume c.Arterial compliance d.Venous return e.Plasma volume
c
A patient has a dead space of 150 milliliters, FRC of 3 liters, tidal volume (VT) of 650 milliliters, expiratory reserve volume (ERV) of 1.5 liters, total lung capacity (TLC) of 8 liters, and respiratory rate of 15 breaths/ min. What is the residual volume (RV)? A) 500 milliliters B) 1000 milliliters C) 1500 milliliters D) 2500 milliliters E) 6500 milliliters
c
A twofold increase in which of the following would result in the greatest increase in the transport of oxygen across the capillary wall? A) Capillary hydrostatic pressure B) Intercellular clefts in the capillary wall C) Oxygen concentration gradient D) Plasma colloid osmotic pressure E) Capillary wall hydraulic permeability
c
A young woman comes to the emergency department with a vertebral compression fracture. Radiographs of the spine indicate generalized demineralization. She is vegetarian, does not smoke or drink alcohol, and has a normal plasma potassium concentration of 5.4 mEq/L, a sodium concentration of 136 mEq/L, and a plasma calcium concentration of 7.0 mg/dl. Her vitamin D3 value is several times greater than normal, although her 1,25-dihydroxycholecalciferol concentration is at the lower limit of detectability. She has been in renal failure for the past 5 years and undergoes hemodialysis three times each week. What is the cause of her low 1,25-di- hydroxycholecalciferol level? A) Metabolic acid` C) She is unable to form 1,25-dihydroxycholecalciferol because of her extensive kidney disease D) She is undergoing dialysis with a dialysis fluid that does not contain calcium E) She is taking receiving calcium supplements
c
Autoregulation of tissue blood flow in response to an increase in arterial pressure occurs as a result of which of the following? a.Decrease in vascular resistance b.Initial decrease in vascular wall tension c.Excess delivery of nutrients such as oxygen to the tissue d.Decrease in tissue metabolism
c
In a normally functioning kidney, which part of the tubule has the lowest permeability to water during antidiuresis? A) A B) B C) C D) D E) E
c
The type A intercalated cells in the collecting tubules A) Are highly permeable to urea during antidiuresis B) Secrete K+ C) Secrete H+ D) Are the main site of action of furosemide E) Are the main site of action of thiazide diuretic
c
What would decrease venous hydrostatic pressure in the legs? a.Increase in right atrial pressure b.Pregnancy c.Movement of leg muscles d.Presence of ascitic fluid in the abdomen
c
What would tend to decrease GFR by more than 10% in a normal kidney? A) Decrease in renal arterial pressure from 100 to 85 mm Hg B) 50% decrease in afferent arteriolar resistance C) 50% decrease in efferent arteriolar resistance D) 50% increase in the glomerular capillary filtration coefficient E) Decrease in plasma colloid osmotic pressure from 28 to 20 mm Hg
c
Which changes would you expect to find after administering a vasodilator drug that caused a 50% decrease in afferent arteriolar resistance and no change in arterial pressure? A) Decreased renal blood flow, decreased GFR, and decreased peritubular capillary hydrostatic pressure B) Decreased renal blood flow, decreased GFR, and increased peritubular capillary hydrostatic pressure C) Increased renal blood flow, increased GFR, and increased peritubular capillary hydrostatic pressure D) Increased renal blood flow, increased GFR, and no change in peritubular capillary hydrostatic pressure E) Increased renal blood flow, increased GFR, and decreased peritubular capillary hydrostatic pressure
c
Which components of the circulatory system contain the largest percentage of the total blood volume? a.Arteries b.Capillaries c.Veins d.Pulmonary circulation e.Heart
c
Which nephron segment is the primary site of magnesium reabsorption under normal conditions? A) Proximal tubule B) Descending limb of the loop of Henle C) Ascending limb of the loop of Henle D) Distal convoluted tubule E) Collecting ducts
c
Which of the following increases the rate of excretion of calcium ions by the kidney? A) A Decrease In Calcitonin Concentration In The Plasma B) An increase in phosphate ion concentration in theplasma C) A decrease in the plasma level of PTH D) Metabolic alkalosis
c
Which of the following tends to decrease potassium secretion by the cortical collecting tubule? A) Increased plasma potassium concentration B) A diuretic that decreases proximal tubule sodium reabsorption C) A diuretic that inhibits the action of aldosterone (e.g., spironolactone) D) Acute alkalosis E) High sodium intake
c
Which of the following vessels has the greatest total cross-sectional area in the circulatory system? a.Aorta b.Small arteries c.Capillaries d.Venules e.Vena Cava
c
Which part of the circulation has the highest compliance? a.Capillaries b.Large arteries c.Veins d.Aorta e.Small arteries
c
Which condition normally causes arteriolar vasodilation during exercise? a.Decreased plasma potassium ion concentration b.Increased histamine release c.Decreased plasma nitric oxide concentration d.Increased plasma adenosine concentration e.Decreased plasma osmolality
d
Which mechanism would tend to decrease capillary filtration rate? A) Increased capillary hydrostatic pressure B) Decreased plasma colloid osmotic pressure C) Increased interstitial colloid osmotic pressure D) Decreased capillary water permeability E) Decreased arteriolar resistance
d
Which of the following would be expected to occur during a Cushing reaction caused by brain ischemia? a.Increase in parasympathetic activity b.Decrease in arterial pressure c.Decrease in heart rate d.Increase in sympathetic activity
d
Which statement is correct? A) Urea reabsorption in the medullary collecting tu- bule is less than in the distal convoluted tubule during antidiuresis B) Urea concentration in the interstitial fluid of the renal cortex is greater than in the interstitial fluid of the renal medulla during antidiuresis C) The thick ascending limb of the loop of Henle reabsorbs more urea than the inner medullary collecting tubule during antidiuresis D) Urea reabsorption in the proximal tubule is greater than in the cortical collecting tubule
d
Which statement is true? A) ADH increases water reabsorption from the as- cending loop of Henle B) Water reabsorption from the descending loop of Henle is normally less than that from the ascending loop of Henle C) Sodium reabsorption from the ascending loop of Henle is normally less than that from the descending loop of Henle D) Osmolarity of fluid in the early distal tubule would be less than 300 mOsm/L in a dehydrated person with normal kidneys and increased ADH levels E) ADH decreases the urea permeability in the medullary collecting tubules
d
if a person has a kidney transport maximum for glucose of 350 mg/min, a GFR of 100 ml/min, a plasma glucose level of 150 mg/dl, a urine flow rate of 2 ml/min, and no detectable glucose in the urine, what would be the approximate rate of glucose reabsorption, assuming normal kidneys? A) Glucose reabsorption cannot be estimated from these data B) 0 mg/min C) 50 mg/min D) 150 mg/min E) 350 mg/min
d
In a person on a high-potassium (200 mmol/day) diet, which part of the nephron would be expected to secrete the most potassium? A) Proximal tubule B) Descending loop of Henle C) Ascending loop of Henle D) Early distal tubule E) Collecting tubules
e
In control conditions, flow through a blood vessel is 100 ml/min under a pressure gradient of 50 mm Hg. What would be the approximate flow through the vessel after increasing the vessel diameter to four times normal, assuming that the pressure gradient was maintained at 50 mm Hg? a.300 ml/min b.1600 ml/min c.1000 ml/min d.16,000 ml/min e.25,600 ml/min
e
The diameter of a precapillary arteriole is increased in a muscular vascular bed. A decrease in which of the following would be expected? a.Capillary filtration rate b.Vascular conductance c.Capillary blood flow d.Capillary hydrostatic pressure e.Arteriolar resistance
e
The pleural pressure of a normal 56-year-old woman is approximately −5 cm H2O during resting conditions immediately before inspiration (i.e., at functional residual capacity [FRC]). What is the pleural pressure (in cm H2O) during inspiration? a.+1 b.+4 c.0 d.−3 e.−7
e
When the respiratory drive for increased pulmonary ventilation becomes greater than normal, a special set of respiratory neurons that are inactive during normal quiet breathing then becomes active, contributing to the respiratory drive. These neurons are located in which structure? a.Apneustic center b.Dorsal respiratory center c.Nucleus of the tractus solitarius d.Pneumotaxic center e.Ventral respiratory group
e
Which Of The Following Would Cause The Greatest Decrease in GFR in a person with otherwise normal kidneys? A) Decrease in renal arterial pressure from 100 to 80 mm Hg in a normal kidney B) 50% increase in glomerular capillary filtration coefficient C) 50% increse in proximal tubular sodium reabsorption D) 50% decrease in afferent arteriolar resistance E) 50% decrease in efferent arteriolar resistance F) 5 mm Hg decrease in Bowman's capsule pressure
e
Which of the following capillaries has the lowest capillary permeability to plasma molecules? A) Glomerular B) Liver C) Muscle D) Intestinal E) Brain
e
Which of the following has similar values for both intracellular and interstitial body fluids? A) Potassium ion concentration B) Colloid osmotic pressure C) Sodium ion concentration D) Chloride ion concentration E) Total osmolarity
e
Which of the following stimulates the secretion of PTH? A) An increase in extracellular calcium ion activity above the normal value B) An increase in calcitonin concentration C) Respiratory acidosis D) Increased secretion of PTH-releasing hormone from the hypothalamus E) None of the above
e
Which of the following would be expected to increase the measured airway resistance? a.Stimulation of parasympathetic nerves to the lungs b.Low lung volumes c.Release of histamine by mast cells d.Forced expirations e.All of the above
e
At which renal tubular sites would the concentration of creatinine be expected to be highest in a normally hydrated person? A) The concentration would be the same in all renal tubular segments because creatinine is neither secreted or reabsorbed B) Glomerular filtrate C) End of the proximal tubule D) End of the loop of Henle E) Distal tubule F) Collecting duct
f
An increase in which of the following would tend to increase lymph flow? A) Hydraulic conductivity of the capillary wall B) Plasma colloid osmotic pressure C) Capillary hydrostatic pressure D) Arteriolar resistance E) A and C
e
Which of the following would likely lead to hypona- tremia? A) Excessive ADH secretion B) Restriction of fluid intake C) Excess aldosterone secretion D) Administration of 2 liters of 3% NaCl solution E) Administration of 2 liters of 0.9% NaCl solution
a
A 22-year-old woman runs a 10-kilometer race on a hot day and becomes dehydrated. Assuming that her ADH levels are very high and that her kidneys are functioning normally, in which part of the renal tubule is the most water reabsorbed? A) Proximal tubule B) Loop of Henle C) Distal tubule D) Cortical collecting tubule E) Medullary collecting duct
a
A 62-year-old woman has previously had a unilateral nephrectomy after diagnosis of renal carcinoma. Her GFR (estimated from creatinine clearance) is 50 ml/min, her urine flow rate is 2.0 ml/min, and her plasma glucose concentration is 200 mg/100 ml. If she has a kidney transport maximum for glucose of 150 mg/min, what would be her approximate rate of glucose excretion? A) 0 mg/min B) 50 mg/min C) 100 mg/min D) 150 mg/min E) 200 mg/min F) 300 mg/min G) Glucose excretion rate cannot be estimated from these data
a
A patient has a GFR of 100 ml/min, her urine flow rate is 2.0 ml/min, and her plasma glucose concentration is 200 mg/100 ml. If the kidney transport maximum for glucose is 250 mg/min, what would be her approxi- mate rate of glucose excretion? A) 0 mg/min B) 50 mg/min C) 100 mg/min D) 150 mg/min E) 200 mg/min F) 300 mg/min G) Glucose excretion rate cannot be estimated from these data
a
A patient has a GFR of 100 ml/min, her urine flow rate is 2.0 ml/min, and her plasma glucose concentration is 200 mg/100 ml. If the kidney transport maximum for glucose is 250 mg/min, what would be her approximate rate of glucose excretion? A) 0 mg/min B) 50 mg/min C) 100 mg/min D) 150 mg/min E) 200 mg/min F) 300 mg/min G) Glucose excretion rate cannot be estimated from these data
a
An increase in which of the following tends to increase capillary filtration rate? A) Capillary wall hydraulic conductivity B) Arteriolar resistance C) Plasma colloid osmotic pressure D) Interstitial hydrostatic pressure E) Plasma sodium concentration
a
If the average hydrostatic pressure in glomerular capillaries is 50 mm Hg, the hydrostatic pressure in the Bowman's space is 12 mm Hg, the average colloid osmotic pressure in the glomerular capillaries is 30 mm Hg, and there is no protein in the glomerular ultrafiltrate, what is the net pressure driving glomerular filtration? A) 8 mm Hg B) 32 mm Hg C) 48 mm Hg D) 60 mm Hg E) 92 mm Hg
a
In a person on a very low potassium diet, which part of the nephron would be expected to reabsorb the most potassium? A) A B) B C) C D) D E) E
a
Increases in both renal blood flow and GFR are caused by which mechanism? A) Dilation of the afferent arterioles B) Increased glomerular capillary filtration coefficient C) Increased plasma colloid osmotic pressure D) Dilation of the efferent arterioles
a
The GFR of a 26-year-old man with glomerulonephritis decreases by 50% and remains at that level. For which substance would you expect to find the greatest increase in plasma concentration? A) Creatinine B) K+ C) Glucose D) Na+ E) Phosphate F) H+
a
The diameter of a precapillary arteriole is decreased in a muscle vascular bed. Which change in the microcirculation would be expected? A) Decreased capillary filtration rate B) Increased interstitial volume C) Increased lymph flow D) Increased capillary hydrostatic pressure E) Decreased arteriolar resistance
a
The function of which of the following is increased by an elevated parathyroid hormone concentration? A) Osteoclasts B) Hepatic formation of 25-hydroxycholecalciferol C) Phosphate Reabsorption Pathways In The Renal Tubules D) All the above
a
Va increases several fold during strenuous exercise. Which factor is most likely to stimulate ventilation during strenuous exercise? A) Collateral impulses from higher brain centers B) Decreased mean arterial pH C) Decreased mean arterial Po2 D) Decreased mean venous Po2 E) Increased mean arterial Pco2
a
Which of the following segments of the circulatory system has the highest velocity of blood flow? a.Aorta b.Arteries c.Capillaries d.Venules e.Veins
a
A 26-year-old construction worker is brought to the emergency department with a change in mental status after working a 10-hour shift on a hot summer day (average outside temperature was 97°F [36°C]). The man had been sweating profusely during the day but did not drink fluids. He has a fever of 102°F [39°C], a heart rate of 140 beats/min, and a blood pressure of 100/55 mm Hg in the supine position. Upon examination, he has no perspiration, appears to have dry mucous membranes, and is poorly oriented to person, place, and time. Assuming that his kidneys were normal yesterday, which set of hormone levels describes his condition, compared with normal? A) High ADH, high renin, low angiotensin II, low aldosterone B) Low ADH, low renin, low angiotensin II, low aldosterone C) High ADH, low renin, high angiotensin II, low aldosterone D) High ADH, high renin, high angiotensin II, high aldosterone E) Low ADH, high renin, low angiotensin II, high aldosterone
d
A 72-year old man had abdominal surgery to remove an abdominal tumor. Pathohistological studies revealed that the tumor mass contained a large number of vessels. The most likely stimulus for the growth of the vessels in a solid tumor is an increase in which of the following? a.Growth hormone b.Plasma glucose concentration c.Angiostatin growth factor d.Vascular endothelial growth factor e.Tissue oxygen concentration
d
A decrease in the production of which of the following would most likely result in chronic hypertension? A) Aldosterone B) Thromboxane C) Angiotensin II D) Nitric oxide
d
A healthy, 25-year-old medical student participates in a 10-kilometer charity run for the American Heart Association. Which muscles does the student use (contract) during expiration? a.Diaphragm and external intercostals b.Diaphragm and internal intercostals c.Diaphragm only d.Internal intercostals and abdominal recti e.Scaleni f.Sternocleidomastoid muscles
d
An increase in which of the following would be expected to decrease blood flow in a vessel? a.Pressure gradient across the vessel b.Radius of the vessel c.Plasma colloid osmotic pressure d.Viscosity of the blood e.Plasma sodium concentration
d
Blood flow to a tissue remains relatively constant despite a reduction in arterial pressure (autoregulation). Which of the following would be expected to occur in response to the reduction in arterial pressure? a.Decreased conductance b.Decreased tissue carbon dioxide concentration c.Increased tissue oxygen concentration d.Decreased vascular resistance e.Decreased arteriolar diameter
d
In a person with normal kidneys and normal lungs who has chronic metabolic acidosis, you would expect to find all of the following, compared with normal, except: A) Increased renal excretion of NH4Cl B) Decreased urine pH − extraction C) Decreased urine HCO3 D) Increased plasma HCO3− concentration (blood) E) Decreased plasma Pco2
d
Listed below are the hydrostatic and oncotic pressures within a microcirculatory bed. Plasma colloid osmotic pressure = 25 mm Hg Capillary hydrostatic pressure = 25 mm Hg Venous hydrostatic pressure = 5 mm Hg Arterial pressure = 80 mm Hg Interstitial fluid hydrostatic pressure = −5 mm Hg Interstitial colloid osmotic pressure = 10 mm Hg Capillary filtration coefficient = 10 ml/min/mm Hg What is the rate of net fluid movement across the capillary wall? 25 ml/min 50 ml/min 100 ml/min 150 ml/min 200 ml/min
d
Movement of solutes such as Na+ across the capillary walls occurs primarily by which process? A) Filtration B) Active transport C) Vesicular transport D) Diffusion
d
PTH does what directly? A) Controls the rate of 25-hydroxycholicalciferol formation B) Controls the rate of calcium transport in the mu- cosa of the small intestine C) Controls the rate of formation of calcium-binding protein D) Controls the rate of formation of 1,25-dihydroxy- cholicalciferol E) Stimulates renal tubular phosphate reabsorption
d
Several students are trying to see who can generate the highest expiratory flow. Which muscle is most effective at producing a maximal effort? A) Diaphragm B) Internal intercostals C) External intercostals D) Rectus abdominis E) Sternocleidomastoid
d
The afferent (sensory) endings for the Hering-Breuer reflex are mechanoreceptors located in the... a.Carotid Arteries b.Alveoli c.External Intercostals d.Bronchi and bronchioles e.Diaphragm
d
The basic rhythm of respiration is generated by neurons located in the medulla. What limits the duration of inspiration and increases respiratory rate? a.Apneustic center b.Dorsal respiratory group c.Nucleus of the tractus solitarius d.Pneumotaxic center e. Ventral respiratory group
d
The tendency for turbulent flow is greatest in which of the following? a.Arterioles b.Capillaries c.Small arterioles d.Aorta
d
Under normal conditions, flow through a blood vessel is 100 ml/min with a pressure gradient of 50 mm Hg. What would be the approximate flow through the vessel after increasing the diameter by 50%, assuming that the pressure gradient is maintained at 100 mm Hg? a.100 ml/min b.150 ml/min c.300 ml/min d.500 ml/min e.700 ml/min
d
Under normal physiological conditions, blood flow to the skeletal muscles is determined mainly by which of the following? a.Sympathetic nerves b.Angiotensin 2 c.Vasopressin d.Metabolic needs e.Capillary osmotic pressure
d
What is the most important pathway for respiratory response to systemic arterial CO2 (PCO2)? a.CO2 activation of the carotid bodies b.Hydrogen ion (H+) activation of the carotid bodies c.CO2 activation of the chemosensitive area of the medulla d.H+ activation of the chemosensitive area of the medulla e.CO2 activation of receptors in the lungs
d
When the dietary intake of K+ increases, body K+ balance is maintained by an increase in K+ excretion primarily by which of the following? A) Decreased glomerular filtration of K+ B) Decreased reabsorption of K+ by the proximal tubule C) Decreased reabsorption of K+ by the thick ascending limb of the loop of Henle D) Increased K+ secretion by the late distal and collecting tubules E) Shift of K+ into the intracellular compartment
d
Which change would you expect to find in a dehydrat- ed person deprived of water for 24 hours? A) Decreased plasma renin activity B) Decreased plasma antidiuretic hormone concentration C) Increased plasma atrial natriuretic peptide concentration D) Increased water permeability of the collecting duct
d
A 55-year-old overweight male patient reports frequent urination, and his blood pressure is 165/98 mm Hg. Based on 24-hour creatinine clearance, you estimate his GFR to be 150 ml/min. His plasma glucose is 400 mg/100 ml. Assuming that his renal transport maximum for glucose is normal, as shown in the above figure, what would be the approximate rate of urinary glucose excretion for this patient? A) 0 mg/min B) 100 mg/min C) 150 mg/min D) 225 mg/min E) 300 mg/min F) The information provided is inadequate to estimate the glucose excretion rate
e
A 60-year old woman has a mean arterial blood pressure of 130 mm Hg, a heart rate of 78 BPM, a right atrial pressure of 0 mm Hg. a cardiac output of 3.5 L/min. He also has a pulse pressure of 35 mm Hg and a hematocrit of 40. What is the approximate total peripheral vascular resistance in this man? a.17 mm Hg/L/min b.1.3 mm Hg/L/min c.13 mm Hg/L/min d.27 mm Hg/L/min e.37 mm Hg/L/min
e
A 65-year-old man has congestive heart failure. He has a cardiac output of 4 L/min, arterial pressure of 115/85 mm Hg, and a heart rate of 90 beats per min. Further tests by a cardiologist reveal that the patient has a right atrial pressure of 10 mm Hg. An increase of which of the following would be expected in this patient? a.Plasma colloid osmotic pressure b.Interstitial colloid osmotic pressure c.Arterial pressure d.Cardiac output e.Vena cava hydrostatic pressure
e
A 72-year old man had abdominal surgery to remove an abdominal tumor. Pathohistological studies revealed that the tumor mass contained a large number of vessels. The most likely stimulus for the growth of the vessels in a solid tumor is an increase in which of the following? a.Growth hormone b.Plasma glucose concentration c.Angiostatin growth factor d.Tissue oxygen concentration e.Vascular endothelial growth factor (VEGF)
e
A healthy 22-year-old female medical student has an exercise stress test at a local health club. An increase in which of the following is most likely to occur in this woman's skeletal system? a.Vascular conductance b.Blood flow c.Carbon dioxide concentration d.Arteriolar diameter e.All of the above
e
An ACE inhibitor is administered to a 65-year-old man with a 20-year history of hypertension. The drug lowered his arterial pressure and increased his plasma levels of renin and bradykinin. Which mechanism would best explain the decrease in arterial pressure? A) Inhibition of angiotensin I B) Decreased conversion of angiotensinogen to angiotensin I C) Increased plasma levels of bradykinin D) Increased plasma levels of renin E) Decreased formation of angiotensin II
e