Renal Physiology (Module 8) Flashcards
(200 cards)
A case of a 22 y/o male medical student who was brought to ED with a chief complaint of severe vomiting due to alcohol intoxication. Which of the following manifests the corresponding compensation?
a. Respiratory rate of 25
b. pH of 7.5
c. Respiratory rate of 12
d. Decreased breath sounds
Answer: A. Respiratory rate of 25
Patient is experiencing metabolic alkalosis (vomiting). As a compensatory mechanism, patient will have respiratory acidosis (hyperventilation). (Renal Physiology Part III handout by Doc Banzuela, pages 3-4)
This is a case of a 45 y/o male pt. diagnosed with DM type I. Pt. was brought to the hospital after an incident of insulin overdose. Which of the following electrolyte imbalance will be expected?
a. Potassium of 2
b. Potassium of 4
c. Sodium of 130
d. Sodium of 145
Answer: A. Potassium of 2
Insulin stimulates K+ uptake into cells by increasing the activity of Na+-K+ ATPase. Overdose of insulin would lead to hypokalemia. (Constanzo, page 281)
The following cause an increase in the potassium secretion except:
a. Hypoaldosteronism
b. Loop diuretics
c. Alkalosis
d. Luminal anions
Answer: A. Hypoaldosteronism
Increased distal K+ secretion caused by high K+ diet, hyperaldosteronism, alkalosis, thiazide diuretics, loop diuretics, and luminal anions. (BRS Physiology, page 161)
RDJ, 56 y/o male, was brought to ED with complaint of chest pain and was given morphine sulfate. After several minutes, he was noted to have hypoventilation. Which of the following could be his ABG results?
a. pH = 7.3, PCO2 = 50
b. pH = 7.3, PCO2 = 35
c. pH = 7.5, PCO2 = 35
d. pH = 7.5, PCO2 = 50
Answer: A.pH = 7.3, PCO2 = 50
Respiratory acidosis may be brought about with the use of opiates (ex. morphine sulfate). Respiratory acidosis manifests as a decrease in normal pH (7.4) and increase in partial pressure of carbon dioxide (35-45). (Renal Physiology Part III handout by Doc Banzuela, page 3)
In gradient time transport, the rate of transport depends on different factors except:
a. Permeability of the membrane
b. Electrochemical gradient
c. Some substances that are passively reabsorbed demonstrate a transport maximum
d. The time that the fluid containing substances remains in contact with luminal membrane of the tubule
Answer: C. Some substances that are passively reabsorbed demonstrate a transport maximum
Gradient time transport does not have transport maximum and threshold. (Guyton and Hall, page 351)
Multiple mechanisms control the amount of sodium and water excreted by the kidney. What are the two primary systems involved in regulating the concentration of sodium and osmolarity of extracellular fluid.
A. RAAS and Thirst Mechanism
B. Fluid Buffer System and RAAS
C. Osmoreceptor–ADH system and Thirst Mechanism
D. Respiratory System and Renal System
Answer: C. Osmoreceptor–ADH system and Thirst Mechanism
The kidneys minimize fluid loss during water deficits through the osmoreceptor-ADH feedback system. Adequate fluid intake, however, is necessary to counterbalance whatever fluid loss occur through sweating and breathing and through the gastrointestinal tract. (Guyton and Hall, page 384)
A patient was brought to the ER due to a massive blood loss. What are the stimulus that could increase the ADH secretion? A. Increased arterial pressure B. Decreased blood volume C. Decreased osmolarity D. Decreased blood concentration
Answer: B. Decrease Blood Volume
Whenever blood pressure and blood volume are reduced, such as during hemorrhage, increased ADH secretion causes increased fluid reabsorption by the kidneys helping to restore blood pressure and blood volume towards normal. (Guyton and Hall, page 668)
Which factor stimulates activation of angiotensin II to have increase the effects of the thirst mechanism? A. Hypovolemia B. Hypertension C. Hyponatremia D. Hypokalemia
Answer: A. Hypovolemia
Angiotensin II is stimulated by factors associated with hypovolemia and low blood pressure. It helps restore blood volume and blood pressure toward normal after fluid intake. (Guyton and Hall, page 671)
When the sodium concentration increases about 2 mEq/L above normal, \_\_\_\_\_\_\_\_\_\_\_\_\_ is activated. A. Osmoreceptor-ADH Mechanism B. RAAS C. Threshold for drinking D. Thirst Mechanism
Answer: D. Thirst Mechanism
High sodium concentration will activate the thirst mechanism to increase blood volume. (Guyton and Hall, page 671)
Which hormones play an important role in regulating sodium reabsorption by the renal tubules? A. Angiotensin II and ADH B. ADH and Aldosterone C. Aldosterone and Angiotensin I D. Angiotensin II and Aldosterone
Answer: D. Angiotensin II and Aldosterone
When sodium intake is low, increased levels of these hormones stimulate sodium reabsorption by the kidneys. (Guyton and Hall, page 672)
When is the desire to drink only completely satisfied?
A. when plasma osmolarity and blood volume returns to normal
B. when plasma osmolality and sodium concentration returns to normal
C. when sodium concentration and plasma volume returns to normal
D. when blood volume and plasma osmolality returns to normal
Answer: A. when plasma osmolarity and blood volume returns to normal
These two affect the activation of thirst mechanism, so when these normalize, thirst mechanism is inactivated. (Guyton, page 671)
Which of the following hormones inhibits phosphate reabsorption? A. LH B. ADH C. PTH D. Aldosterone
Answer: C. PTH
PTH causes phosphaturia and increased urinary cAMP. It acts on the proximal tubule by activating adenylate cyclase, generating cyclic AMP (cAMP), and inhibiting Na+–PO4 co-transport. (BRS, page 163)
This causes increased urinary Ca+ excretion. A. Loop antidiuretics B. Aldosterone C. Loop diuretics D. PTH
Answer: C. Loop diuretics
Because Ca++ reabsorption is linked with Na+ reabsorption in the loop of Henle, inhibiting Na+ reabsorption with a loop diuretic also inhibits Ca++ reabsorption. Loop diuretics can be used in the treatment of hypercalcemia. (BRS, page 163)
Excess water ingestion and a decrease in extracellular fluid osmolarity leads to \_\_\_\_\_\_\_. A. more ADH formed B. less ADH formed C. no change in ADH levels D. accumulation of ADH in the kidneys
Answer: B. less ADH formed
The renal tubules decrease their permeability for water, less water is reabsorbed, and a large volume of dilute urine is formed. This in turn concentrates the body fluids and returns plasma osmolarity back to normal.
(Guyton and Hall, page 382)
ADH release is also controlled by cardiovascular reflexes that respond to decreases in blood pressure and/or blood volume, including:
A. arterial baroreceptor reflexes and cardiopulmonary reflexes
B. ischemic reflexes and cardiopulmonary reflexes
C. arterial baroreceptor reflexes and muscle stretch reflexes
D. carotid reflexes and ischemic reflexes
Answer: A. arterial baroreceptor reflexes and cardiopulmonary reflexes
These reflex pathways originate in high pressure regions of the circulation such as the aortic arch and carotid sinus, and in the low pressure regions, especially in the cardiac atria. (Guyton and Hall, page 383)
The increased water permeability in the distal nephron segments causes increased water \_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_\_ of a concentrated urine. A. filtration, excretion B. reabsorption, excretion C. reabsorption, filtration D. filtration, secretion
Answer: B. reabsorption, excretion
Water reabsorption will decrease urine volume, making it more concentrated upon excretion. Furthermore, filtration only occurs in the glomerulus and never in the tubules. (Renal Physiology Handouts by Doc Banzuela)
If both the \_\_\_\_\_ and thirst mechanisms fail simultaneously, plasma sodium concentration and osmolarity are poorly controlled. A. ADH B. Aldosterone C. RAAS D. LH
Answer: A. ADH
When sodium intake is increased after blocking the total ADH thirst system, relatively large changes in plasma sodium concentration occur. In the absence of the ADH thirst mechanisms, no other feedback mechanism is capable of adequately regulating plasma sodium concentration and osmolarity. (Guyton and Hall, page 385)
In general, the primary stimuli that increase salt appetite are those associated with _______.
A. Sodium deficits and decreased blood volume
B. Potassium deficits and increased blood volume
C. Phosphate deficits and decreased blood volume
D. Calcium deficits and decreased blood volume
Answer: A. Sodium deficits and decreased blood volume
The neuronal mechanism for salt appetite is analogous to that of the thirst mechanism. Also, circulatory reflexes elicited by low blood pressure or decreased blood volume affect both thirst and salt appetite at the same time. (Guyton and Hall, page 387)
If Na+ excretion is less than Na+ intake, where would it be retained and would the volume in the said compartment increase or decrease? A. ECF, decrease in the ECF volume B. ECF, increase in the ECF volume C. ICF, increase in ICF volume D. ICF, decrease in ICF volume
Answer: B. ECF, increase in ECF volume
If Na+ excretion is less than Na+ intake, then the person has a positive Na+ balance. In this case, extra Na+ is retained in the body, primarily in the ECF. When the Na + content of ECF is increased, there is increased ECF volume or ECF volume expansion; blood volume and arterial pressure also increase, and there may be edema. (Constanzo, page 274)
If sodium excretion exceeds sodium intake, what would happen to the ECF volume?
A. ECF volume will increase
B. ECF volume will decrease
C. ECF volume will remain the same
D. ECF volume will increase then decrease
Answer: B. ECF volume will decrease
If Na+ excretion is greater than Na + intake, then a person is in negative Na+ balance. When excess Na+ is lost from the body, there is a decreased Na+ content of ECF, decreased ECF volume or ECF volume contraction, and decreased blood volume and arterial pressure (Constanzo, page 273)
Patient with Type I Diabetes Mellitus was taken to the hospital due to hyperkalemia. What could have caused this?
A. Increased dietary intake of potassium
B. The body is producing more potassium
C. Patient has not been taking his insulin shots
D. Decreased excretion of potassium
Answer: C. Patient has not been taking his insulin shots
Insulin stimulates K+ uptake into cells by increasing the activity of Na+-K+ ATPase. Physiologically, this effect of insulin is responsible for the uptake of dietary K+ into the cells following a meal. Deficiency of insulin, as occurs in Type I DM, produces the opposite effect: decreased uptake of K+ into cells and hyperkalemia. (Constanzo, page 285)
In a person with low potassium diet, how is the body able to reabsorb K+?
A. through I-cells of the stomach
B. through K-cells of the kidney
C. through principal cell of the nephron
D. through alpha-intercalated cells of the nephron
Answer: D. Alpha-intercalated cells
When a person is on a low K+ diet, K+ can be reabsorbed in the terminal nephron segments by the α-intercalated cells. Luminal membrane of these cells contains an H+-K+ ATPase. (Constanzo, page 288)
Patient with history of pyloric ulcer with partial gastric outlet obstruction presented with persistent vomiting for 3 days. Upon examination, has decreased respiratory rate. What is the significance of the decreased respiratory rate?
A. Patient has metabolic acidosis and the decreased respiratory rate is to increase pCO2 levels
B. Patient has respiratory acidosis and decreased respiratory rate is to decrease pH
C. Patient has respiratory alkalosis and decreased respiratory rate is to decrease pH
D. Patient has metabolic alkalosis and decreased respiratory rate is to decrease pH
Answer: D. Patient has metabolic alkalosis and decreased respiratory rate is to decrease pH
Loss of HCl from the stomach by vomiting causes metabolic alkalosis. Respiratory acidosis (hypoventilation) is the compensatory reaction to decrease pH back to normal. (Renal Physiology handout by Doc Banzuela)
What cells in the kidney secretes K+? A. Mesangial cells B. Macula Densa C. Podocyte D. Principal cells
Answer: D. Principal cells