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