Urinary System
During reabsorption of water in the proximal convoluted tubule, what causes water to osmose from the lumen into the interstitial space?
an increase in the osmolarity of the interstitium
Which of the following transporters in the luminal membrane results in secretion?
Na+-H+ countertransport
How is the osmotic concentration of the tubular fluid adjusted in the DCT and collecting system?
active transport
In the countercurrent multiplication mechanism:
active transport at the apical surface of the thick ascending limb of the nephron loop moves sodium and chloride ions out of the tubular fluid and into the peritubular fluid of the renal medulla.
Which factor controlling glomerular filtration rate (GFR) is usually 0 mm Hg under normal circumstances?
capsular colloid osmotic pressure
What is the function of the vasa recta?
collect and transport water and solutes within the renal medulla in the juxtamedullary nephron
Which renal structure begins in the renal cortex, and carries tubular fluid through the osmotic gradient in the renal medulla?
collecting duct
Variable secretion of potassium and hydrogen ions is a specific function of which renal structure?
collecting system
What is the primary driving force (pressure) that produces glomerular filtration?
hydrostatic pressure of blood (blood pressure)
What is the osmolarity of the filtrate at the end of the proximal tubule?
isotonic - 300 mOsm
Hormonal or metabolic complications such as those associated with diabetes or glomerulonephritis result in:
polyuria
Which substance would be found in higher concentration if the membrane were damaged?
protein
Which metabolite(s) or nutrient(s) is/are not present in normal urine?
proteins
In which region of the nephron is tubular fluid first formed?
proximal convoluted tubule
Which nephron part do you think will be most at risk of damage due to chronic hypertension?
renal corpuscle
The active transport of which ion out of proximal convoluted tubule cells causes the reabsorption of both water and solutes?
sodium
Hypertensive kidney failure would most likely result in which of the following conditions?
Increased retention of creatinine
Calculate the net filtration pressure if capillary hydrostatic pressure is 60 mm Hg, capillary osmotic pressure is 25 mm Hg, and capsular hydrostatic pressure is 10 mm Hg.
25 mm Hg
In severe dehydration or blood loss, what would be the levels of ADH and what would be the urine flow rate?
ADH - high; low urine flow rate (0.25 ml/min)
In overhydration, what would be the levels of ADH (high, normal, or low) and what would be the osmolarity of the urine?
ADH - low; 100 mOsm (urine)
Which of the following statements about ADH (antidiuretic hormone) is correct?
ADH is released by the posterior pituitary gland.
______ deliver blood to the glomerulus.
Afferent arterioles
Which of the following statements about aldosterone is NOT correct?
Aldosterone increases sodium reabsorption by increasing the number of Na+-K+ ATPase pumps in the luminal membrane of the proximal tubule.
Aldosterone
Aldosterone increases the number of passive sodium channels in the luminal membrane of the distal tubule and collecting duct, thus aiding sodium reabsorption. Aldosterone is produced in the adrenal cortex. Aldosterone is stimulated by decreased plasma sodium levels and increased plasma potassium levels.
When someone's blood pressure rises slightly, the function of their urinary system will probably most immediately change in which of the following ways?
GFR will rise
Which ion/solute movement or event does not occur in the distal convoluted tubule?
Osmosis pulls water out of the tubular fluid and into the peritubular fluid.
Which event correctly occurs under maximum ADH stimulation?
The DCT and collecting system become more permeable to water.
Kidneys
The left kidney lies slightly superior to the right kidney. The kidneys are retroperitoneal organs. Each kidney is stabilized and protected by three concentric layers of connective tissue. The kidneys lie between vertebrae T12 and L3.
Which of the following substances is not normally found in filtrate?
blood cells and large particles
Which of the following is comprised of a layer of collagen fibers that covers the outer surface of the kidney?
fibrous capsule
Which transport mechanism(s) results from blood pressure that forces water and solutes across the membranes of the glomerular capillaries and into the capsular space?
filtration
When the pH of body fluids decreases, which of the following are secreted in exchange for sodium ions reabsorbed in the distal convoluted tubule?
hydrogen ions
The ______ control(s) capillary diameter and the rate of capillary blood flow.
mesangial cells
The ______ collects the urine produced by a single kidney lobe.
minor calyx
Which of the following reabsorbs 25% of the water in the nephron?
nephron loop
If the osmotic pressure in the glomerular capillaries increased from 28 mm Hg to 35 mm Hg, would net filtration increase or decrease?
net filtration would decrease
What is the limiting factor for the reabsorption of most actively transported solutes in the proximal tubule?
number of transport carriers in the luminal membrane
The decreased intracellular concentration of sodium in tubular cells during active transport is caused by which of the following mechanisms?
the sodium-potassium ATPase pump in the basolateral membrane
Most solutes that are reabsorbed in the proximal convoluted tubule use which of the following pathways?
transcellular