Unit1: Ch 32- Structure and Function of the Kidney (Porth 5th Ed)

Question 1

A dialysis technician is providing care for a client with chronic renal failure. The technician would recognize which of the following characteristics of healthy kidneys?
Select all that apply.
A) The kidneys are contained within the peritoneal cavity.
B) Blood vessels, nerves, and ureters all connect with the kidney at the hilus.
C) The medulla of the kidney contains the glomeruli.
D) Each kidney consists of lobes, with each lobe comprised of nephrons.
E) Each nephron contains several hundred glomeruli that perform filtration.

Answer 1

Ans: B, D
Feedback:
The hilus is the point of nerve and blood input and urine output for each kidney, and each kidney is composed of up to 18 lobes. The kidneys are outside the peritoneal cavity, and glomeruli exist in the outer cortex. Each nephron contains just one glomerulus.

Question 2

A patient in the ICU has been diagnosed with hypovolemic shock. His BP is 88/53, heart rate 122, and respiratory rate 26. Given these vital signs, the nurse should expect the urine output to be
A) maintained between 30 and 50 mL/hour with no sediment in the bag.
B) increased to 60+ mL/hour with dilute urine.
C) decreased below 30 mL/hour with decreased GFR.
D) the patient’s normal amount with dark, concentrated urine.

Answer 2

Ans: C
Feedback:
Under conditions of decreased perfusion or increased sympathetic nervous system stimulation, blood flow is redistributed away from the cortex toward the medulla. This redistribution of blood flow decreased glomerular filtration while maintaining the urine-concentrating ability of the kidneys, a factor that is important during conditions such as shock. The urine output would not increase, nor be normal.

Question 3

At which of the following locations in the nephron would a health care professional first expect blood to be largely free of plasma proteins?
A) Proximal convoluted tubule
B) Bowman space
C) Loop of Henle
D) Afferent arteriole

Answer 3

Ans: B
Feedback:
Active filtration occurs when the whole blood enters via the afferent arteriole in to the glomerular capillaries, and the blood is then filtered into the Bowman space, removing plasma proteins. The filtrate that enters the proximal convoluted tubule and the loop of Henle is already free of plasma proteins.

Question 4

Which of the following statements about mesangial cells within the glomerulus is accurate? Select all that apply. Mesangial cells
A) cover the entire amount of endothelial cells contained within the capillaries.
B) have phagocytic properties that remove macromolecular materials.
C) exhibit vasodilator properties to assist with increase in blood flow in times of stress.
D) enlarge (hyperplasia) in response to glomerular diseases.
E) are coiled and drain Bowman capsule.

Answer 4

Ans: B, D
Feedback:
Mesangial cells possess phagocytic properties and remove macromolecular materials that enter the intercapillary spaces. Mesangial cells also exhibit contractile properties in response to neurohumoral substances and are thought to contribute to the regulation of blood flow through the glomerulus. Mesangial hyperplasia and increased mesangial matrix occur in a number of glomerular diseases. The nephron tubule, called the proximal convoluted tubule, is coiled and drains the Bowman capsule

Question 5

A nurse educator is orientating new nurses to a renal unit of the hospital. Which of the following teaching points should the nurse include as part of a review of normal glomerular function?
A) “Nephrons are delicate structures that cannot endure the high pressure that exists in capillary beds elsewhere in the body.”
B) “Glomerular filtrate is very similar in composition to blood plasma found
elsewhere in circulation.”
C) “Dilation of the afferent arteriole allows more blood into the nephron and
increases the glomerular filtration rate.”
D) “The glomerulus is located between an arteriole and a venule that work together to regulate blood flow.”

Answer 5

Ans: B
Feedback:
Because filtration achieves the removal of nearly all blood proteins, the glomerular filtrate is nearly identical to plasma. Nephrons require high pressure to function, and dilation decreases the glomerular filtration rate. The glomerulus is located between two arterioles.

Question 6

While assessing a patient with urosepsis, the ICU nurse notes the patient’s BP is 80/54; HR 132; RR 24; and pulse oximetry 89% on 6 lpm O2. Over the last hour, the patient’s urine output is 15 mL. When explaining to a new graduate nurse, the nurse will emphasize that the patient’s status may relate to that
A) the infection is deep inside the kidney, and it will take a long time for the
antibiotics to kill the bacteria.
B) the patient’s sympathetic nervous system has been stimulated that has resulted in vasoconstriction of the afferent arteriole, which causes a decrease in renal blood flow.
C) the glomerular filtration system gets overwhelmed in times of stress (like
infections) and can become clogged with waste material from the bacteria.
D) the ability to transport substances from the tubular fluid into the peritubular capillaries becomes impaired, which results in fluid being forced out of capillaries into the glomerulus.

Answer 6

Ans: B
Feedback:
During periods of strong sympathetic stimulation, such as shock, constriction of the afferent arteriole causes a marked decrease in renal blood flow and thus glomerular filtration pressure. Consequently, urine output can fall almost to zero.

Question 7

Which of the following substances is most likely to be reabsorbed in the tubular segments of the nephron using passive transport mechanisms?
A) Water
B) Sodium
C) Phosphate
D) Calcium

Answer 7

Ans: A
Feedback:
Water is passively reabsorbed across tubular epithelial membranes, while ions like sodium, phosphate, and calcium necessitate active transport.

Question 8

When explaining to a class of nursing students enrolled in pathophysiology, the instructor states, “the majority of energy used by the kidney is for
A) filtration of drugs out of the body.”
B) secretion of erythropoietin for production of RBCs.”
C) active sodium transport mechanisms.”
D) removal of excess glucose from the blood.”

Answer 8

Ans: C
Feedback:
The bulk of energy used by the kidney is for active sodium transport mechanisms that facilitate sodium reabsorption and cotransport of other electrolytes and substances such as glucose and amino acids.

Question 9

Damage to which of the following areas of a nephron would most likely result in impaired secretion and reabsorption?
A) Distal tubule
B) Loop of Henle
C) Proximal tubule
D) Collecting tubule

Answer 9

Ans: C
Feedback:
Approximately two thirds of the absorption and secretion that occur in the tubular system take place in the proximal tubule.

Question 10

When explaining the role of the proximal tubule in terms of medication administration, the nursing instructor will emphasize that which of the following medications are bound to plasma proteins and require the proximal tubule secretion of exogenous organic compounds to help with filtration? Select all that apply.
A) Penicillin
B) Aspirin
C) Morphine sulfate
D) Potassium chloride
E) Sodium chloride

Answer 10

Ans: A, B, C
Feedback:
The proximal tubule secretes exogenous organic compounds such as penicillin, aspirin, and morphine. Many of these compounds can be bound to plasma proteins and are not freely filtered in the glomerulus. Therefore, excretion by filtration alone eliminates only a small portion of these potentially toxic substances from the body.

Question 11

Which of the following statements most accurately captures the function of the
ascending loop of Henle?
A) Urine is concentrated by the selective absorption of free water in the ascending limb.
B) Sodium and water are reabsorbed in equal amounts, reducing filtrate quantity but maintaining osmolality.
C) The majority of solute and water reabsorption occurs in the ascending loop of Henle.
D) Impermeability to water and absorption of solutes yields a highly dilute filtrate.

Answer 11

Ans: D
Feedback:
The osmolality of the filtrate reaches a low of 100 mOsm/kg of water in the ascending limb as a result of its impermeability to water.

Question 12

To treat enuresis in a young girl, her pediatrician prescribes desmopressin, an antidiuretic hormone (ADH) nasal spray, before bedtime. What is the most likely rationale for this treatment?
A) It removes water from the filtrate and returns it to the vascular compartment.
B) It lessens the amount of fluid entering the glomerulus.
C) It leads to the production of dilute urine.
D) It causes tubular cells to lose their water permeability.

Answer 12

Ans: A
Feedback:
ADH maintains extracellular volume by returning water to the vascular compartment. This leads to the production of concentrated urine by removing water from the tubular filtrate. In exerting its effect, ADH produces a marked increase in water permeability in tubular cells.

Question 13

Following an automobile accident where the patient had a traumatic amputation of his lower leg and lost greater than 40% of his blood volume, he is currently not producing any urine output. The nurse bases this phenomena on which of the following humoral substances responsible for causing severe vasoconstriction of the renal vessels?
A) Aquaproin-2 channels
B) Angiotensin II and ADH
C) Renin and potassium ions
D) Albumin and norepinephrine

Answer 13

Ans: B
Feedback:
Increased sympathetic activity causes constriction of the afferent and efferent arterioles and thus a marked decrease in renal blood flow. Intense sympathetic stimulation can produce marked decreases in renal blood flow and GFR. Humoral substances, including angiotensin II, ADH, and endothelins, produce vasoconstriction of renal blood flow. Aquaporin-2 channels, potassium ions, and albumin do not have vasoconstriction properties.

Question 14

A physician who is providing care for a 71-year-old male client with a recent diagnosis of renal failure and an acid–base imbalance is explaining some of the underlying etiology of the man’s diagnoses to him and his family. Which of the following phenomena would most accurately underlie the teaching that the physician provides?
A) The kidneys are integral to the reabsorption of hydrogen ions and maintenance of a low pH.
B) Blood buffer systems and respiratory control can compensate for inadequate renal control of pH.
C) The kidneys have the primary responsibility for eliminating excess hydrogen ions from the body.
D) pH is kept at an optimal level through the renal secretion of bicarbonate ions in blood filtrate.

Answer 14

Ans: C
Feedback:
The kidneys have the primary responsibility for maintaining body pH by eliminating excess hydrogen ions from the body, a function that blood buffer systems and respiratory control are incapable of. Hydrogen ions must be eliminated, not retained, and bicarbonate must be produced as part of buffer action, not secreted.

Question 15

Which of the following clients on a medical unit of a hospital is most likely to be experiencing health problems that may be attributable to kidney disease?
A) An 81-year-old female client with osteoporosis and anemia
B) A 77-year-old client with urinary retention due to benign prostatic hyperplasia (BPH)
C) A 55-year-old woman with a recent stroke secondary to long-standing
hypertension
D) A 60-year-old man with a systemic fungal infection requiring intravenous
antibiotics.

Answer 15

Ans: A
Feedback:
The kidneys play central roles in both vitamin D activation and regulation of red blood cell production, deficiencies of which may result in osteoporosis and anemia, respectively. BPH, stroke, and infection are less likely to result from kidney disease.

Question 16

While living and hiking in the Rocky Mountains, a gentleman slipped and fell. He goes to an urgent care where an x-ray was done, and some blood was drawn for a CBC. The clinic informs him that he is anemic. What may contribute to this person’s anemia? Select all that apply.
A) Living in a high altitude
B) Tissue hypoxia
C) Inability to manufacture erythropoietin
D) Destruction of RBCs caused by natural killer cells
E) Dehydration

Answer 16

Ans: A, B, C
Feedback:
The synthesis of erythropoietin is stimulated by tissue hypoxia, which may be brought about by anemia, residing at high altitudes, or impaired oxygenation of tissues due to cardiac or pulmonary disease. Dehydration will cause an elevated level of RBCs.

Question 17

Which of the following patients on a geriatric medical unit is most likely to require slow-release potassium supplements on a regular basis?
A) A 90-year-old female who is taking an aldosterone antagonist to treat pulmonary edema
B) An 81-year-old male who takes a thiazide diuretic to control his hypertension
C) A 79-year-old male with heart failure who is receiving a loop diuretic
D) An 83-year-old female who is taking an osmotic diuretic to address severe
peripheral edema

Answer 17

Ans: B
Feedback:
A common side effect of thiazide diuretics is increased potassium losses in the urine, which may necessitate potassium supplementation. Aldosterone antagonists, loop diuretics, and osmotic diuretics are less likely to induce hypokalemia.

Question 18

A 62-year-old woman with high blood pressure is to begin long-term treatment with a thiazide diuretic that she thinks she will need to take for some time. What should the nurse expect to happen to her potassium and calcium levels?
A) Her potassium and calcium levels will not change.
B) Her potassium and calcium levels will both go down.
C) Her potassium level will drop, but her calcium level may rise.
D) Her potassium level will rise, but her calcium level may drop.

Answer 18

Ans: C
Feedback:
Thiazide diuretics increase the loss of potassium in urine. Because calcium is actively reabsorbed in the distal convoluted tubule, it is likely that her calcium level will go up, especially if she takes it for a long time.

Question 19

A patient in a hospital is frustrated at the inconvenience of having to collect his urine for an entire day and night as part of an ordered 24-hour urine collection test. He asks the nurse why the test is necessary since he provided a single urine sample 2 days ago. How could the nurse best respond to the patient’s question?
A) “A single urine sample lets your care team determine if there are bacteria in your urine, but other tests of urine chemistry need a longer-term view.”
B) “Current lab tests aren’t able to detect the small quantities of most substances contained in a single urine sample.
C) “Only a longer-term test is able to show whether your kidneys are letting sugar spill out into your urine.”
D) “Often why an abnormal substance shows up in urine test, a 24-hour urine collection is needed to determine exactly how much it is present in your urine.”

Answer 19

Ans: D
Feedback:
Twenty-four–hour urine tests are often used to quantify the amount of substances, such as proteins, that an individual’s kidneys are spilling. Single urine samples are able to assess more parameters than just the presence of bacteria, and they are sufficient in quantity to detect numerous substances such as glucose.

Question 20

Which of the following lab results would be associated with abnormalities in kidney function? Select all that apply.
A) An absence of protein in a urine sample
B) Increased creatinine level
C) Urine gravity of 1.038 and normal serum creatinine levels
D) Decreased blood urea nitrogen (BUN) level
E) Detectable levels of glucose in a urine sample
F) Elevated cystatin-C level.

Answer 20

Ans: B, E, F
Feedback:
Increased creatinine and BUN are associated with abnormalities in renal function, as is the presence of glucose in a urine sample. Urine samples normally lack protein and have a specific gravity of 1.038 to 1.040. An elevated BUN coupled with normal creatinine is likely not attributable to impaired kidney function.