CardioP - Chapter 21 - 17 questions

Which of the following substances are almost totally reabsorbed from the tubules? I. Sodium II. Potassium III. Chloride IV. Bicarbonate a. I, II b. II, III, IV c. I, II, III, IV d. II, III

C Sodium, potassium, chloride, and bicarbonate are almost totally reabsorbed from the tubules.

Which of the following are structures that help compose the nephron? I. Bowman's capsule II. Proximal convoluted tubule III. Loop of Henle IV. Collecting duct a. I, II, III b. I, IV c. I, II, III, IV d. II, III

C The nephron is composed of the following structures, listed in the order in which fluid flows through them: (1) Bowman's capsule, (2) the proximal convoluted tubule, (3) the loop of Henle, (4) the distal convoluted tubule, and (5) the collecting duct.

Which of the following hormones inhibit the effects of aldosterone? I. ANH II. BNP III. ADH IV. Cortisol a. I, II b. II, III, IV c. I, II, III, IV d. II, III

A Atrial natriuretic hormone (ANH) and B-type natriuretic peptide (BNP) inhibit the effects of aldosterone and thus tend to prevent water reabsorption and increase urine volume.

Which of the following is an example of an osmotic diuretic? a. Mannitol b. Furosemide c. Hydrochlorothiazide d. Acetazolamide

A Osmotic diuretics are substances that freely pass through the glomerular membrane into the tubular filtrate but are not easily reabsorbed by the peritubular capillaries. Mannitol is an example of such a diuretic; its site of action is mainly in the proximal tubules.

Which of the following autoregulatory mechanisms of renal blood flow is the most important? a. Afferent vasodilator mechanism b. Efferent vasodilator mechanism c. GFR d. Juxtaglomerular mechanism

A The most important autoregulatory mechanism of renal blood flow is the afferent vasodilator mechanism.

Which of the following substances, when excessive, does the nephron clear from the plasma? I. Sodium II. Potassium III. Chloride IV. Calcium a. I, II, III b. III, IV c. I, II, III, IV d. II, III, IV

A The nephron clears the blood plasma of metabolic products such as urea, creatinine, and uric acid. The nephron also clears the plasma of substances that accumulate in the body to excessive quantities, such as sodium, potassium, chloride, and hydrogen ions.

Which of the following substances is secreted at the juxtaglomerular apparatus when systemic blood pressure decreases? a. Renin b. Angiotensin c. Aldosterone d. Vasopressin

A When systemic blood pressure decreases, cells of the juxtaglomerular apparatus secrete renin, an enzyme that activates angiotensin, which ultimately leads to widespread systemic arteriole constriction.

Glomerular filtrate is the same as plasma except it does not contain which of the following? a. Calcium b. Proteins c. Hydrogen ions d. Potassium

B Glomerular filtrate is the same as plasma except it contains almost no proteins.

Which of the following is an example of a loop diuretic? a. Mannitol b. Furosemide c. Hydrochlorothiazide d. Acetazolamide

B Loop diuretics include furosemide (Lasix), torsemide (Demadex), and ethacrynic acid (Edecrin).

Which of the following is a diuretic that is effective and quick-acting in treating edema of congestive heart failure? a. Mannitol b. Furosemide c. Hydrochlorothiazide d. Acetazolamide

B Loop diuretics include furosemide (Lasix), torsemide (Demadex), and ethacrynic acid (Edecrin). These drugs are effective, quick-acting agents useful in treating edema of congestive heart failure.

Why would a patient on mechanical ventilation have a rapid weight gain? a. Lack of motility slows the metabolic rate. b. Positive pressure ventilation decreases venous return, decreases blood pressure, and stimulates renin-angiotensin-aldosterone. c. Positive pressure ventilation forces fluid into the third space. d. Positive pressure ventilation increases venous return and stimulates release of antidiuretic hormone.

B Positive intrapleural pressure resists venous blood return and may decrease the cardiac output, which in turn decreases blood pressure. A fall in blood pressure activates mechanisms that attempt to increase blood volume; that is, the body responds as though it were suffering from hypovolemia. As a result, the renin-angiotensin-aldosterone system is activated, causing sodium reabsorption and water retention. In addition, antidiuretic hormone is secreted, adding to the fluid retention.

Which of the following parts of the nephron is highly impermeable to water? a. Thin portion of the loop of Henle b. Thick portion of the loop of Henle c. Proximal tubule d. Distal tubule

B The ascending portion of Henle's loop is highly impermeable to water, especially its thick portion.

Which of the following is the main factor determining the degree of filtration across the glomerular membrane? a. Glomerular blood's oncotic pressure b. Glomerular blood's hydrostatic pressure c. Tubular hydrostatic pressure d. Tubular oncotic pressure

B The main factor establishing the pressure gradient between glomerular capillary blood and the capsular filtrate is the glomerular blood's hydrostatic pressure (Figure 21-4).

Under the influence of ADH, what type of urine is excreted by the kidneys? a. Low volume, low concentration b. Low volume, high concentration c. High volume, low concentration d. High volume, high concentration

B Under the influence of antidiuretic hormone (ADH) the kidney excretes low-volume, highly concentrated urine.

What percentage of the glomerular filtrate is reabsorbed into the blood? a. 1% b. 25% c. 50% d. 99%

D At a glomerular filtration rate (GFR) of 125 mL/min, approximately 180 L of filtrate is produced daily. Of this filtrate, approximately 99% is reabsorbed into the blood for a total urine output of slightly more than 1.5 L per day.

Which of the following are considered substances that are eliminated by the kidneys? I. Hemoglobin II. Urea III. Creatinine IV. Bilirubin a. I, II, III b. III, IV c. I, II, III, IV d. II, III, IV

D Unwanted substances eliminated by the kidneys include urea (a by-product of amino acid metabolism), creatinine (from muscle cells), uric acids (from nucleic acids), bilirubin (from hemoglobin breakdown), and metabolites of assorted hormones; in addition, the kidneys eliminate various toxins and foreign substances, whether produced by the body or ingested

Which of the following is the best clinical indicator of perfusion adequacy? a. Skin color b. Blood pressure c. Heart rate d. Urine output

D Urine output is a useful clinical indicator of perfusion adequacy.