Renal Function Chapter 26

b. exceeding the threshold for glucose reabsorption.

12. The underlying mechanism which directly results in glycosuria is a. filtration of glucose from the glomerulus. b. exceeding the threshold for glucose reabsorption. c. secretion of glucose into the distal tubule. d. the mechanism is unknown.

d. 80% Serious renal impairment generally does not occur until 75% to 90% of the total nephrons have been damaged. The other answer options are incorrect.

Serious renal impairment generally does not occur until of the total nephrons have been damaged. a. 20% b. 40% c. 60% d. 80%

a. Protein intake c. Fluid intake d. Catabolism e. Renal function

The blood urea nitrogen (BUN) level is affected by which factors? (Select all that apply.) a. Protein intake b. Fat intake c. Fluid intake d. Catabolism e. Renal function

d. serum creatinine level.

The glomerular filtration rate is most accurately reflected in the a. blood urea nitrogen level. b. urinary output. c. serum osmolality. d. serum creatinine level.

d. may be saturated at high filtered glucose loads (The glucose transporter in the proximal tubule may be saturated at high filtered glucose loads; glycosuria then results. A transport maximum does exist beyond which glycosuria occurs. A sodium-dependent protein co-transporter is needed. The transporter is not ATP-dependent.)

The glucose transporter in the proximal tubule a. has no transport maximum. b. does not depend on sodium reabsorption. c. is ATP-dependent. d. may be saturated at high filtered glucose loads.

b. hydrostatic pressure in glomerular capillaries.

The main driving force for glomerular filtration is a. oncotic pressure in the Bowman's capsule. b. hydrostatic pressure in glomerular capillaries. c. permeability of the glomerular membrane. d. solute content of the blood in the glomerular capillaries.

c. reabsorb interstitial fluid. (The vasa recta are capillaries that surround the loops of Henle and collecting ducts and absorb interstitial fluid. The vasa recta do not secrete renin or urea, nor do they reabsorb NaCl.)

The primary function of the vasa recta is to a. secrete renin. b. reabsorb NaCl. c. reabsorb interstitial fluid. d. secrete urea.

a. proteinuria.

An important sign of glomerular basement membrane dysfunction is a. proteinuria. b. hematuria. c. glycosuria. d. urinary casts.

c. secretion based on aldosterone level.

Excess potassium is excreted from the body by the renal system primarily via a. glomerular filtration based on blood level of potassium. b. reabsorption based on blood level of potassium. c. secretion based on aldosterone level. d. an unknown mechanism.

a. fluid volume excess.

Factors that increase the glomerular filtration rate include a. fluid volume excess. b. increased hydrostatic pressure in the Bowman's capsule. c. high oncotic pressure in glomerular capillary blood. d. obstruction in the renal tubules.

b. occurs in the proximal convoluted tubule.

It is true that glucose reabsorption in the tubules a. occurs passively. b. occurs in the proximal convoluted tubule. c. is unlimited. d. simply does not occur.

c. juxtaglomerular cells. Renin is released from the juxtaglomerular cells. Renin is not released from the posterior pituitary gland, liver, or macula densa cells.

Renin is released from a. the posterior pituitary gland. b. the liver. c. juxtaglomerular cells. d. macula dense cells.

c. muscle breakdown.

Serum creatinine may be increased by a. carbohydrate intake. b. fat intake. c. muscle breakdown. d. fluid intake.

d. White blood cells 20 per high-power field (These many WBCs in the urine indicate urinary tract infection; 5 or more is not expected. 4.5 is a normal pH. Fewer than 5 RBCs is insignificant. 1.015 is a normal specific gravity.)

Which finding on urinalysis should prompt further evaluation? a. pH 4.5 b. Red blood cells 2 per high-power field c. Specific gravity of 1.015 d. White blood cells 20 per high-power field

a. Aldosterone e. Angiotensin II

Which hormones increase sodium reabsorption from the tubular fluid? (Select all that apply.) a. Aldosterone b. Atrial natriuretic peptide c. Antidiuretic hormone d. Urodilatin e. Angiotensin II

a. glomerular basement membrane. (The basement membrane is an important selectivity barrier of the glomerulus, preventing plasma proteins, RBCs, WBCs, and platelets from passing through the glomerulus. Endothelial tight junctions, epithelial fenestra, and mesangial cells are not the primary selectivity barriers for glomerular filtration.)

1. The primary selectivity barrier for glomerular filtration is the a. glomerular basement membrane. b. endothelial tight junctions. c. epithelial fenestra. d. mesangial cells.

d. proximal tubule. (Approximately two-thirds of the water and electrolytes filtered by the kidney are reabsorbed by the proximal tubule. Two-thirds of the water and electrolytes filtered by the kidney are not reabsorbed by the loop of Henle, collecting tubule, or distal tubule.)

Approximately two-thirds of the water and electrolytes filtered by the kidney are reabsorbed by the a. loop of Henle. b. collecting tubule. c. distal tubule. d. proximal tubule.