Physiology I Exam 3 Flashcards
Renal autoregulation refers to the relative constancy of GFR and renal blood flow. A decrease in arterial pressure and glomerular filtration rate ultimately leads to a reduction in the concentration of sodium ions at the macula densa. This results in which of the following responses that ultimately restores GFR?
Release of renin by the juxtaglomerular apparatus
Release of endothelin by the glomerular capillaries
Release of nitric oxide by the vasa recta endothelium
Release of angiotensin2 by the juxtaglomerular apparatus
Release of renin by the juxtaglomerular apparatus
GFR is determined by the net filtration pressure and the glomerular capillary filtration coefficient. Which of the following factors has the greatest effect on increasing GFR?
Glomerular capillary colloid osmotic pressure
Bowman’s capsule hydrostatic pressure
Bowman’s capsule colloid osmotic pressure
Glomerular hydrostatic pressure
Glomerular hydrostatic pressure
Minimum change disease occurs when the negative charges on the filtration membrane of the glomerulus are not present. What abnormality in the urine would be expected under these conditions?
Urine would contain numerous red blood cells
Urine would contain excess albumin
Urine would contain excess sodium and chloride
Urine would be less concentrated
Urine would contain excess albumin
A number of hormone are involved in the control of glomerular filtration rate. Which of the following preferentially constricts the efferent arteriole but has little to no effect on the afferent arterioles?
Bradykinin
Angiotensin 2
Endothelial-derived nitric oxide
Endothelin
Angiotensin 2
What is, in L/day, represents the GFR in the average adult human?
3
125
180
360
180 L/day
An increase in which of the following factors will result in a decrease in glomerular hydrostatic pressure?
Arterial pressure Afferent arteriole resistance Efferent arteriole resistance Both B and C All of the above
Afferent arteriole resistance
Approximately how much of the total cardiac output is received by the kidneys?
25%
50%
75%
100%
25%
The thin descending loop of Henle is highly permeable to which of the following?
Sodium
Water
Urea
Amino Acids
Water
Aldosterone is an important regulator of sodium reabsorption and potassium secretion; one it its main targets is?
Podocytes
Principle cells
Intercalated cells
Cells of macula densa
Principle cells
Most potassium reabsorption occurs at which of the following sites?
Ascending Loop of Henle
Distal convoluted tubule
Proximal convoluted tubule
Collecting duct
Proximal convoluted tubule
Primary active hydrogen secretion involves a hydrogen-transporting ATPase. It occurs in which of the following parts of the renal tubules?
Descending limb of Henle
Ascending limb of Henle
Late distal tubules in the intercalated cells
Early collecting tubules in principle cells
Late distal tubules in intercalated cells.
ADH (anti-diuretic hormone) is formed in the supraoptic and paraventricular nuclei. It is secreted by specialized neurons from which of the following areas?
Adrenal cortex
Adrenal medulla
Anterior pituitary
Posterior pituitary
Posterior pituitary
A normal 70 kg human must excrete about 600 mOsm of solute each day in order to get rid of waste products of metabolism and ions that are ingested. The maximal urine concentrating ability is 1200 mOsm/L. Which of the following represents the obligatory urine volume that must be excreted each day to get rid of metabolic waste products?
- 0 L/day
- 5 L/day
- 3 L/day
- 0 L/day
0.5 L/day
ADH acts on what region of the nephron?
Proximal convoluted Tubule
Descending Loop of Henle
Ascending Loop of Henle
Distal Convoluted tubule
Distal convoluted tubule
Which of the following reflects the amount of urine that the kidneys can excrete per day when there is a large excess of water?
180 liters
75 liters
20 liters
4 liters
20 liters
Which of the following reflects the maximum urine concentration that can be produced by the kidneys?
6000-7000 mOsm/L
5500-6000 mOsm/L
1200-1400 mOsm/L
2000-2400 mOsm/L
1200-1400 mOsm/L
Osmoreceptor cells are located in which of the following regions?
Adjacent to carotid bodies
In the macula densa
In the anterior part of the third ventricle
In the distal collecting ducts
In the anterior part of the third ventricle
What segment of the nephron is NOT permeable to water?
Proximal Convoulted tubule in the presence of ADH
Descending Loop of Henle in the presence of ADH
Ascending Loop of Henle in the presence of ADH
Distal Convoluted Tubule in the presence of ADH
Ascending Loop of Henle in the presence of ADH
Which of the following plays a major role in stimulating potassium excretion by the kidney tubules?
Aldosterone
Angiotensin II
Sodium ion
PTH
Aldosterone
Approximately how much of the body’s supply of calcium is stored in bone?
1%
47%
78%
99%
99%
How much of filtered calcium is excreted by the kidneys?
1%
47%
78%
99%
1%
Which of the following cells reabsorbs potassium during potassium depletion?
Intercalated cells
Principle cells
Chief cells
Podocytes
Intercalated cells
A high potassium intake would have which of the following effects on potassium excretion associated with increased renal tubular flow rate?
Potassium excretion would increase with increased tubular flow rate
Potassium excretion would decrease with increased tubular flow rate
There would be little effect
Tubular flow rate would be decreased
Potassium excretion would increase with increased tubular flow rate
Which of the following describes a valid change in potassium distribution due to an acid base abnormality?
Metabolic acidosis decreases extracellular K+ concentration
Metabolic alkalosis increases extracellular K+ concentration
Metabolic acidosis increases extracellular K+ concentration
Both A and B are valid
Metabolic acidosis increases extracellular K+ concentration
Which of the following buffer systems is most important in buffering renal tubular fluid?
Phosphate buffer system
Carbonate buffer system
Bicarbonate buffer system
Hemoglobin buffer system
Phosphate buffer system
Compounds that dissociate incompletely into hydrogen ions and a conjugate base are members of which of the following compounds?
Strong acids
Weak acids
Strong bases
Weak bases
Weak acids
The bicarbonate buffer system consists of a bicarbonate salt and which of the following?
Weak acid
Strong acid
Weak base
Strong base
Weak acid
Which of the following buffer systems is the most important extracellular buffer system?
Phosphate buffer system
Carbonate buffer system
Bicarbonate buffer system
Hemoglobin buffer system
Bicarbonate buffer system
Most bicarbonate reabsorption occurs in which of the following parts of the renal tubule?
Proximal tubule
Descending limb of Henle
Ascending limb of Henle
Distal tubule
Proximal tubule
Which of the following occurs when a decrease in bicarbonate ion results in a decrease in the ratio of bicarbonate ion to carbon dioxide in the extracellular fluid?
Respiratory acidosis
Respiratory alkalosis
Metabolic acidosis
Metabolic alkalosis
Metabolic acidosis
Respiratory alkalosis due to decrease in carbon dioxide concentration caused by hyperventilation is compensated for by which of the following mechanisms?
Increased ventilation rate
Decreased ventilation rate
Renal excretion of bicarbonate ion
Renal addition of new bicarbonate ion to extracellular fluid
Renal excretion of bicarbonate ion
Which of the following would be a result of increased levels of angiotensin II?
Decreased blood pressure
Increased vasoconstriction
Increased natriuresis
Decreased aldosterone levels
Increased vasoconstriction
A 1-sodium, 2-chloride, 1-potassium co-transporter is found in the luminal membrane of which part of the renal tubule?
Proximal convoluted tubule
Thin descending limb of Henle
Thick ascending limb of Henle
Distal convoluted tubule
Thick ascending limb of Henle
If tidal volume is 0.5 liters, dead space is 0.15 liters, and breathing rate is 12 times per minute, What is the minute ventilation?
- 8 liters
- 0 liters
- 0 liters
- 8 liters
6.0 liters