Nephrons
Why is the presence of microvilli important to the epithelial tissue of the PCT?
a.because most reabsorption occurs at the PCT
b.because filtration is taking place
c.because secretion of toxins and ions are actively secreted to waste at the PCT
d.because hormonally controlled reabsorption of water and sodium occurs in the PCT
a.because most reabsorption occurs at the PCT
Angiotensin II
A) causes vasoconstriction
B) stimulates aldosterone secretion
c) stimulates ADH secretion
d) increases the sensation of thirst
e) all of these are correct
e) all of these are correct
True or False?
Sodium is the most prevalent cation in the extracellular and intracellular fluid compartments.
False. While Na+ is the most predominant in plasma and interstitial fluid (extracellular), K+ is the most predominant cation in intracellular fluid.
Buffers
a) release H+ when pH increases
b) resist changes in the pH of a solution
c) include the proteins of the blood
d) all of these are correct
d) all of these are correct
The amount of plasma that enters the Bowman capsule per minute is the
a) glomerular filtration rate (GFR)
b) renal plasma flow
c) renal fraction
d) renal blood flow
a) glomerular filtration rate (GFR)
An appropriate response to hypocalcemia would be:
a) increase calcitonin secretion
b) increase PTH secretion
c) decrease aldosterone secretion
d) inhibit ADH secretion
b) increase PTH secretion
Respiratory alkalosis is caused by ________ and can be compensated for by the production of a more ___________ urine.
a) hypoventilation, basic
b) hypoventilation, acidic
c) hyperventilation, acidic
d) hyperventilation, basic
d) hyperventilation, basic
The ability to control the micturition reflex depends on the ability to control which muscle?
a.urogenital diaphragm
b.internal urethral sphincter
c.external urethral sphincter
d.coccygeus
c.external urethral sphincter
What volume of glomerular filtrate do adults make every day?
a) 1-5 liters
b) 80 liters
c) 180 liters
d) 250 liters
c) 180 liters
The juxtaglomerular cells of the ________ and the macula densa cells of the __________ form the juxtaglomerular apparatus.
a) afferent arteriole; proximal convoluted tubule
b) afferent arteriole, distal convoluted tubule
c) efferent arteriole, proximal convoluted tubule
d) efferent arteriole, distal convoluted tubule
b) afferent arteriole, distal convoluted tubule
All of the following EXCEPT _____ are effects of angiotensin II.
a.elevation of glomerular pressures and GFR
b.inhibition of ADH release
c.elevation of arterial pressure throughout the body
d.stimulation of Na+ reabsorption in the DCT
b. inhibition of ADH release
An increase in blood CO2 levels is followed by a(n) _______ in H+ and a(n) _____________in blood pH.
a) increase, increase
b) increase, decrease
c) decrease, increase
d) decrease, decrease
b) increase, decrease
Which of the following structures are located in the renal cortex? Select all that apply.
Collecting ducts
Distal convoluted tubules
Papillary ducts
Renal corpuscles
Proximal convoluted tubules
Distal convoluted tubules, renal corpuscles, and proximal convoluted tubules.
True or False: If blood pressure falls, blood flow to the kidneys is reduced, which increases activity of the renin– angiotensin–aldosterone-ADH system and, in turn, restores blood pressure to its original level.
True
Which of these conditions reduces filtration pressure in the glomerulus?
a) elevated blood pressure
b) constriction of the afferent arterioles
c) decreased plasma protein in the glomerulus
d) dilation of the afferent arterioles
e) decreased capsular hydrostatic pressure
b) constriction of the afferent arterioles
Wayne’s cardiac muscle cells have been releasing ANP in response to overstretching of his heart walls. What is the effect of the release of ANH?
a.ANH release could cause a heart attack.
b. ANH blocks the release of ADH and aldosterone.
c. Water is conserved at the kidneys.
d. Blood volume and blood pressure increase.
b. ANH blocks the release of ADH and aldosterone.
High levels of bicarbonate ions in the urine indicate
a) a low level of H+ secretion into the urine
b) that the kidneys are causing blood pH to increase
c) that urine pH is decreasing
d) All of these are correct
a) a low level of H+ secretion into the urine
Identify routes by which water is lost from the body. Select all that apply.
Perspiration
Cellular metabolism
Urination
Defecation
Respiration
Ingestion
Perspiration, urination, defecation, respiration
What is the primary cause of hypercalcemia?
a.hyperparathyroidism
b.excessive consumption of vitamin D supplements
c.chronic renal failure
d.alcoholism
a.hyperparathyroidism
How would the absence of juxtamedullary nephrons affect the volume of urine and its osmotic concentration?
a.decrease volume; decrease osmotic concentration
b.decrease volume; increase osmotic concentration
c.increase volume; decrease osmotic concentration
d.increase volume; increase osmotic concentration
c.increase volume; decrease osmotic concentration
A patient has the following symptoms: slight increase in extracellular fluid volume, large decrease in plasma sodium concentration, very concentrated urine, and cardiac filibration. An imbalance of what hormone is responsible for these symptoms? Are the symptoms caused by oversecretion or undersecretion of the hormone?
Imbalance of aldosterone, specifically a decrease in aldosterone.
(Decreased aldosterone leads to decreased sodium reabsorbtion; sodium is lost in the urine, leading to highly concentrated urine. Decreased potassium secretion into nephron also decreases, which leads to higher plasma potassium levels, which can affect the heart)
Critical thinking: In patients with diabetes mellitus, not enough insulin is produced; as a consequence, blood glucose levels increase. If blood glucose levels rise high enough, the kidneys are unable to absorb the glucose from the glomerular filtrate, and glucose "spills over" into the urine. What effect does this glucose have on urine concentration and volume? How does the body adjust to the excess glucose in the urine?
When excess glucose is not absorbed, osmotically, it leads to water remaining in the nephron. This results in the production of a large amount of urine, with a consequent loss of water, salts, and glucose. This loss of salts can compensated for by increasing fluid intake; this also relates to an increased sense of thirst. Increased blood osmolality increases ADH secretion, which in turn increases the distal convoluted tubule and collecting duct's permeability to water. Normally, this allows for reabsorption of water, but if glucose levels are high enough, water loss can increase even with high levels of ADH.
A patient with has low blood pH resulting from an injury that damaged his kidneys. Which of the following will help him compensate for this low pH?
A) increased respiration
B) increased HCO3 absorption
C) increased H+ secretion
D) All of these are correct.
E) Both a and b are correct.
A) Increased respiration
Respiratory system responds to low pH by increasing the rate of respiration.
(Assume damage to the kidneys has affect the nephron's ability to absorb and secrete HCO3 and H+)
What is a possible reason for the development of metabolic acidosis?
a.strenuous exercise resulting in lactic acid accumulation
b.choking on food
c.diabetics who are compliant with their insulin
d.none of the above
a.strenuous exercise resulting in lactic acid accumulation