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| 1 | |
The kidney regulates all of the following except |
| | A) | volume of blood plasma. |
| | B) | concentrations of certain electrolytes and waste products in the blood. |
| | C) | absorption of substances from the gastrointestinal tract |
| | D) | acid-base balance (pH) of the blood plasma. |
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| 2 | |
Examining the structure of the kidney reveals that the |
| | A) | cortex is in contact with the outer capsule. |
| | B) | cortex is divided into eight to fifteen conical renal pyramids. |
| | C) | cortex drains into the minor calyces. |
| | D) | urethra transports urine to the urinary bladder. |
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| 3 | |
Kidney stones are primarily composed of |
| | A) | cholesterol and esters of other steroid compounds. |
| | B) | calcim oxalate crystals and proteins. |
| | C) | heavy metals that precipitate in the urinary filtrate. |
| | D) | salts of weak acids that serve as buffers in the nephron. |
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| 4 | |
Which of the following statements about the micturition reflex is true? |
| | A) | It is controlled by a reflex center located in the lumbar region of the spinal cord. |
| | B) | The internal urethral sphincter is under voluntary control. |
| | C) | Firing of the reflex centers, results in simultaneous contraction of the detrusor muscle and relaxation of the external urethral sphincter, pressuring urine into the urethra. |
| | D) | The urge to urinate is a reflex involving the stimulation of specific autonomic nerves |
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| 5 | |
The blood vessel delivering blood directly to the glomerulus is the |
| | A) | renal artery. |
| | B) | interlobar artery. |
| | C) | arcuate artery. |
| | D) | afferent arteriole. |
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| 6 | |
That portion of the nephron responsible for filtering the blood is the |
| | A) | glomerular capillaries |
| | B) | proximal convoluted tubule. |
| | C) | loop of Henle. |
| | D) | distal convoluted tubule. |
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| 7 | |
The name of the blood vessels that are found in the medulla as part of the vasa recta are the |
| | A) | peritubular capillaries. |
| | B) | afferent arterioles. |
| | C) | arcuate arteries. |
| | D) | efferent arterioles. |
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| 8 | |
Which of the following are not easily filtered by the glomerulus and thus are not normally found in the ultrafiltrate? |
| | A) | red and white blood cells |
| | B) | glucose |
| | C) | amino acids |
| | D) | electrolytes |
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| 9 | |
The net filtration pressure at the glomerulus that results in the formation of ultrafiltrate is |
| | A) | about equal to arterial blood pressure at 100 mmHg. |
| | B) | partially due to the very low colloid osmotic pressure of plasma. |
| | C) | opposed by the high osmotic pressure of ultrafiltrate. |
| | D) | estimated to be approximately 10 mmHg. |
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| 10 | |
Which statement about the glomerular filtration rate (GFR) is false? |
| | A) | The GFR averages approximately 180 L per day (about 45 gallons). |
| | B) | The GFR will increase during fight-or-flight situations due to the vasodilation of afferent arterioles. |
| | C) | A decrease in GFR results in a decrease in the total urine output. |
| | D) | Renal autoregulation maintains the GFR at a relatively constant rate despite fluctuations in the mean arterial blood pressure. |
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| 11 | |
The return of filtered molecules from the nephron tubules back into the blood is called |
| | A) | filtration. |
| | B) | reabsorption. |
| | C) | secretion. |
| | D) | excretion. |
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| 12 | |
Which event does not occur in the proximal convoluted tubule section of the kidney nephron? |
| | A) | Na+ is actively pumped out of the epithelial cells across the basal membranes. |
| | B) | From a higher concentration in the filtrate, Na+ diffuses passively toward a lower concentration in the epithelial cells. |
| | C) | Cl- follows Na+ passively from the filtrate and into the epithelial cells. |
| | D) | Reabsorption of dissolved solutes leaves the remaining filtrate entering the loop of Henle very dilute (hypotonic). |
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| 13 | |
Within the proximal convoluted tubule |
| | A) | Approximately fifteen percent of the original glomerular ultrafiltrate is reabsorbed here and returned to the blood. |
| | B) | Reabsorption of salt and water in this portion of the nephron is regulated by hormones. |
| | C) | The majority of glucose is reabsorbed in this region of the tubule. |
| | D) | The tubular fluid leaving the proximal convoluted tubule hyposmotic with blood. |
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| 14 | |
Regarding the countercurrent multiplier system |
| | A) | The descending limb of the loop of Henle produces a hypotonic filtrate. |
| | B) | Interaction between ascending and descending tubular flow in the loop of Henle where the more salt is extruded, the more concentrated the tissue fluid will be, is an example of negative feedback. |
| | C) | Salt becomes recirculated and trapped in the medullary tissue fluid, increasing in"saltiness" as it accumulates toward the lower tip of the pyramids. |
| | D) | Water is retained in the medulla by the higher colloid osmotic pressure than that of the blood in the vasa recta capillaries. |
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| 15 | |
When the concentration of antidiuretic hormone rises in the blood |
| | A) | the walls of the collecting ducts become less permeable to dissolved solutes and water. |
| | B) | water channels, or aquaporins, appear in the cell membranes of the collecting duct epithelial cells promoting the reabsorption of water from the filtrate. |
| | C) | the ultrafiltrate flowing through the collecting duct becomes more hypotonic. |
| | D) | a greater volume of dilute urine is excreted. |
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| 16 | |
Which statement about antidiuretic hormone (ADH) is false? |
| | A) | ADH is synthesized by neurons of the hypothalamus and released from the posterior pituitary gland. |
| | B) | ADH binds to receptors on the collecting duct cells and activates a cAMP second messenger system. |
| | C) | ADH is released during body dehydration conditions to place water channels, or aquaporins, that reabsorb water along the collecting duct. |
| | D) | ADH is released when osmoreceptors in the hypothalamus sense a decrease in the blood osmolality. |
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| 17 | |
The disease diabetes insipidus |
| | A) | is associated with the excessive secretion or action of antidiuretic hormone. |
| | B) | results from overeating and hypersecretion of hormones by the pancreas. |
| | C) | is characterized by an abnormal increase in glucose concentrations in the blood and urine. |
| | D) | results in the production of a large volume of dilute urine. |
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| 18 | |
Which substance is filtered and then completely (100%) reabsorbed by the nephron? |
| | A) | protein |
| | B) | inulin |
| | C) | urea |
| | D) | glucose |
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| 19 | |
Which substance is both filtered and secreted by the nephron and is, therefore, used to measure the renal plasma flow and estimate the total renal blood flow? |
| | A) | para-aminohippuric acid (PAH) |
| | B) | inulin |
| | C) | urea |
| | D) | glucose |
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| 20 | |
Which of the following is filtered but not reabsorbed? |
| | A) | K+ |
| | B) | inulin |
| | C) | urea |
| | D) | glucose |
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| 21 | |
Which of the following is filtered and partially reabsorbed? |
| | A) | K+ |
| | B) | inulin |
| | C) | urea |
| | D) | glucose |
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| 22 | |
Glucose and amino acids are |
| | A) | only partially filtered into the glomerular ultrafiltrate. |
| | B) | normally found in the urine. |
| | C) | reabsorbed by primary active transport. |
| | D) | reabsorbed completely unless their concentrations in the filtrate exceed their transport maximum (Tm). |
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| 23 | |
The extracellular fluid concentration of which of the following ions is not primarily regulated the kidney? |
| | A) | phosphate |
| | B) | potassium |
| | C) | iron |
| | D) | bicarbonate |
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| 24 | |
Aldosterone |
| | A) | is the major mineralocorticoid hormone secreted by the kidney. |
| | B) | promotes the secretion of Na+ in the late distal convoluted tubule and the cortical region of the collecting duct. |
| | C) | stimulates the secretion of K+ from the peritubular blood into the distal convoluted tubule. |
| | D) | is a protein hormone secreted by the adrenal cortex. |
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| 25 | |
Which statement about the juxtaglomerular apparatus (JGA) is incorrect? |
| | A) | It is the part of the nephron where the afferent arteriole and the distal convoluted tubule contact each other. |
| | B) | The role of the macula densa region of the distal convoluted tubule is to secrete the enzyme renin. |
| | C) | The granular cells within the afferent arteriole are sensitive to renal blood flow (perhaps acting as baroreceptors). |
| | D) | High Na+ concentrations in the filtrate can inhibit the secretion of renin. |
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| 26 | |
The reflex response that would be observed in a person with a high blood volume is |
| | A) | increased renin secretion. |
| | B) | increased aldosterone secretion. |
| | C) | decreased atrial natriuretic peptide secretion. |
| | D) | increased urinary Na+. |
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| 27 | |
Which statement about the role of the kidneys in the regulation of plasma blood pH is false? |
| | A) | The kidneys normall excrete all of the filtered bicarbonate ion. |
| | B) | Hydrogen ion (H+) enters the filtrate in two ways: by glomerular filtration and by secretion into the nephron tubule. |
| | C) | Most of the hydrogen ion secretion occurs across the wall of the proximal convoluted tubule in exchange for the reabsorption of sodium ion. |
| | D) | Buffers like bicarbonate ion can bind and release free H+ and thus can stabilize pH. |
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| 28 | |
Within the proximal convoluted tubule |
| | A) | the apical membranes of the tubule cells directly reabsorb bicarbonate ions. |
| | B) | bicarbonate in the filtrate is converted to carbon dioxide and water by the action of carbonic anhydrase. |
| | C) | the enzyme carbonic anhydrase is only found located in the tubule cell cytoplasm. |
| | D) | during alkalosis, more bicarbonate is reabsorbed and less bicarbonate is excreted to help stabilize the pH. |
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| 29 | |
The two organs most responsible for acid-base balance are the |
| | A) | heart and kidneys. |
| | B) | liver and lungs. |
| | C) | kidneys and lungs. |
| | D) | lungs and heart. |
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| 30 | |
Which statement about acid-base regulation in the kidneys is false? |
| | A) | The kidneys can filter and secrete H+ into the tubular filtrate. |
| | B) | The kidneys normally reabsorb all bicarbonate ions that are filtered at the glomerulus. |
| | C) | Normally some H+ is excreted each day in the urine, thereby raising the urine pH value above that of the blood, which is normally 7.4. |
| | D) | Filtered bicarbonate present in the filtrate is reabsorbed into the blood indirectly as CO2 gas. |
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| 31 | |
Mannitol is considered to be a(n) |
| | A) | loop diuretic. |
| | B) | carbonic anhydrase inhibitor. |
| | C) | osmotic diuretic. |
| | D) | potassium-sparing diuretics. |
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| 32 | |
Diuretics that competitively block the aldosterone-induced stimulation of Na+ reabsorption and K+ secretion in the distal convoluted tubule are known as |
| | A) | carbonic anhydrase inhibitors. |
| | B) | loop diuretics. |
| | C) | thiazides. |
| | D) | potassium-sparing diuretics. |
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| 33 | |
The major kidney function that cannot be performed by artificial dialysis membranes is to |
| | A) | separate molecules on the basis of size. |
| | B) | prevent the diffusion of plasma proteins. |
| | C) | reabsorb Na+, K+, glucose, and other molecules. |
| | D) | allow the free movement of water (solvent). |
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| 34 | |
If a substance is neither filtered, reabsorbed, nor secreted, in which fluid compartment would you expect to find it? |
| | A) | glomerular filtrate |
| | B) | blood in the renal vein |
| | C) | urine |
| | D) | All of the above. |
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| 35 | |
If a substance is filtered and also secreted but not reabsorbed, in which fluid compartment would you NOT expect to find it? |
| | A) | glomerular filtrate |
| | B) | blood in the renal vein |
| | C) | urine |
| | D) | All of the above. |
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| 36 | |
In the _________ of ADH, aquaporins are inserted into the walls of the cortical collecting duct. This will increase the permeability of the cortical collecting duct to water allowing water to diffuse _______ the interstitial fluid of the medulla filtrate. |
| | A) | absence, into |
| | B) | presence, out of |
| | C) | absence, out of |
| | D) | presence, into |
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| 37 | |
The increased production of urine associated with diabetes mellitus is a result of a glomerular filtrate that has an abnormally _________ osmolarity, which _________ the osmotic gradient across the walls of the cortical collecting duct. |
| | A) | high, increase |
| | B) | high, decreases |
| | C) | low, increases |
| | D) | low, decreases |
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| 38 | |
If a diuretic inhibits sodium reabsorption, urinary output will ___________ and blood volume will __________. |
| | A) | increase, increase |
| | B) | increase, decrease |
| | C) | decrease, increase |
| | D) | decrease, decrease |
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| 39 | |
Blood leaving the afferent arteriole goes to the: |
| | A) | peritubular capillary. |
| | B) | glomerulus. |
| | C) | efferent arteriole. |
| | D) | renal vein. |
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| 40 | |
Monosaccharides will normally enter the glomerular filtrate because of: |
| | A) | their size. |
| | B) | charge attraction. |
| | C) | charge repulsion. |
| | D) | both a) and b) |
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