Bio 202

Maintains/preserves the medullary gradient.

Vasa recta

Play a role in urine concentration

Vasa recta

Aquaporin channels are only found in the collecting duct.

false

The collecting duct is impermeable to water in the presence of ADH.

false

Blood filtrate is captured in the lumen of the ________. glomerulus glomerular capsule calyces renal papillae

glomerular capsule

The factor that promotes filtrate formation at the glomerulus is the ________. capsular hydrostatic pressure glomerular hydrostatic pressure myogenic mechanism colloid osmotic pressure of the blood

glomerular hydrostatic pressure

What is the most direct function of the juxtaglomerular complex?

help regulate blood pressure and the rate of blood filtration by the kidneys

What is the most direct function of the juxtaglomerular complex? help regulate blood pressure and the rate of blood filtration by the kidneys help regulate blood pressure and the rate of micturition help regulate urea absorption by the kidneys help regulate water and electrolyte excretion by the kidneys

help regulate blood pressure and the rate of blood filtration by the kidneys

________ pressure must be greater on the capillary side of the filtration membrane to achieve filtration. osmotic hydrostatic

hydrostatic

An increase in the aquaporins in the collecting duct is due to a(n) ________. decrease in the production of ADH increase in the production of ADH decrease in the concentration of the blood plasma increase in the production of aldosterone

increase in the production of ADH

An increase in the permeability of the cells of the collecting tubule to water is due to a(n) ________. increase in the production of ADH increase in the production of aldosterone decrease in the production of ADH decrease in the concentration of the blood plasma

increase in the production of ADH

What is the effect of aldosterone on the cells of the distal convoluted tubule and collecting duct? triggers synthesis of more potassium channels in the apical membranes increases sodium reabsorption by adding channels and pumps inhibits water reabsorption through the apical membranes causes aquaporins to be inserted into the apical membranes

increases sodium reabsorption by adding channels and pumps

Somatic motor neurons must be ________ to relax the external urethral sphincter to allow urination. inhibited stimulated

inhibited

Secretion moves substances: into the interstitial fluid & capillaries into the filtrate

into the filtrate

Reabsorption moves substances: into the filtrate into the interstitial fluid

into the interstitial fluid

The ascending limb of the nephron loop pumps sodium ___________ into the filtrate into the interstitial fluid

into the interstitial fluid

The descending limb of the nephron loop ________.

is permeable to water, which leaves the tubule

_______ nephrons are responsible for producing concentrated urine. juxtamedullary cortical

juxtamedullary

As ventilation increases and more carbon dioxide is removed from the blood, the pH of the blood increases

true

Atrial natriuretic peptide inhibits sodium reabsorption.

true

Electrolytes determine most of the chemical and physical reactions of body fluids.

true

If the GFR is too high, needed substances may pass so quickly through the renal tubules that they are not absorbed and instead are lost in the urine.

true

In the absence of hormones, the distal tubule and collecting ducts are relatively impermeable to water.

true

In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the nephron loop of the juxtamedullary nephrons (the countercurrent multiplier) and the flow of blood through the limbs of the vasa recta (the countercurrent exchanger). This relationship establishes and maintains an osmotic gradient extending from the cortex through the depths of the medulla that allows the kidneys to vary urine concentration dramatically.

true

Prolonged hyperventilation can cause alkalosis.

true

Sodium is pivotal to fluid and electrolyte balance and to the homeostasis of all body systems.

true

Tubular reabsorption is driven by Na/K pumps on the basolateral membrane

true

Tubular secretion helps to control blood pH.

true

Water reabsorption through the proximal convoluted tubule is termed obligatory water reabsorption, whereas water reabsorption through the distal convoluted tubule is termed facultative water reabsorption.

true

When aldosterone release is inhibited, sodium reabsorption is decreased.

true

What would be the effect on urine output if sodium channels in the tubule cells were inhibited? urine volume would increase urine volume would decrease

urine volume would increase

Glomerular filtration is driven by ATP

False

If the GFR is too low, needed substances may pass so quickly through the renal tubules that they are not absorbed and instead are lost in the urine.

False

It is impossible to overhydrate because people need as much water as they can drink to carry out ordinary body functions.

False

Water reabsorption through the proximal convoluted tubule is mostly hormonally regulated, whereas water reabsorption through the distal convoluted tubule is mostly unregulated.

False

Part of the filtration membrane Afferent arterioles Glomerular capillaries Peritubular capillaries Vasa recta Efferent arterioles

Glomerular capillaries

Part of the filtration membrane Peritubular capillaries Glomerular capillaries Vasa recta Efferent arterioles Afferent arterioles

Glomerular capillaries

The body's water volume is closely tied to the level of which of the following ions? Ca K H Na

Na

When sodium potassium pumps move sodium out of a cell, the inside of the cell becomes more

Negative

The deepest part of the medulla of the kidney has an osmolality of 100 mosm 300 mosm 600 mosm 1200 mosm

1200 mosm

Which of the following is the best explanation for why the cells of the proximal convoluted tubule (PCT) contain so many mitochondria? Contraction of the PCT walls moves filtrate through the tubule. A great deal of active transport takes place in the PCT. This provides the energy needed to fight kidney infection. Cells of the PCT go through a great deal of mitosis.

A great deal of active transport takes place in the PCT.

Which of the following is the best explanation for why the cells of the proximal convoluted tubule (PCT) contain so many mitochondria? This provides the energy needed to fight kidney infection. A great deal of active transport takes place in the PCT. Contraction of the PCT walls moves filtrate through the tubule. Cells of the PCT go through a great deal of mitosis.

A great deal of active transport takes place in the PCT.

Which of the hormones below is responsible for facultative water reabsorption?

ADH

High pressure vessel that forces fluid and solutes into the glomerular capsule. Peritubular capillaries Afferent arterioles Vasa recta Efferent arterioles Glomerular capillaries

Afferent arterioles

If blood pressure drops very low (MAP is below 80mmHg) renin enzyme will be secreted by juxtaglomerular cells. Which of the following is NOT likely to occur in response to this release of renin? Glomerular filtration rate (GFR) will decrease. Net filtration pressure (NFP) will decrease. Blood plasma and extracellular fluids volume will increase. Amount of blood in the kidney capillaries will increase.

Amount of blood in the kidney capillaries will increase.

Peritubular capillaries

D

The main fluid compartment outside the cells. Intracellular Extracellular Interstitial Electrolytes Nonelectrolytes

Extracellular

Aldosterone is secreted in response to low extracellular potassium.

False

Fluid in the spaces between cells. Intracellular Extracellular Interstitial Electrolytes Nonelectrolytes

Interstitial

The main fluid compartment located within the cell. Intracellular Extracellular Interstitial Electrolytes Nonelectrolytes

Intracellular

The concentration of phosphate ions is highest in ________. Intracellular fluid (ICF) Extracellular fluid (EXF)

Intracellular fluid (ICF)

The concentration of potassium ions is highest in ________. Intracellular fluid (ICF) Extracellular fluid (EXF)

Intracellular fluid (ICF)

Which of the following does NOT describe the juxtaglomerular complex? It helps control systemic blood pressure by secreting renin. Its juxtaglomerular cells adjust the diameter of the afferent arteriole. It regulates the rate of filtrate formation. Its macula densa cells produce aldosterone.

Its macula densa cells produce aldosterone.

Which of the following does NOT describe the juxtaglomerular complex? It regulates the rate of filtrate formation. Its juxtaglomerular cells adjust the diameter of the afferent arteriole. It helps control systemic blood pressure by secreting renin. Its macula densa cells produce aldosterone.

Its macula densa cells produce aldosterone.

______ blood pressure triggers the juxtaglomerular complex to release renin.

Low

Proximal convoluted tubule

Site at which most of the tubular reabsorption occurs

Glomerulus. Site at which most of the tubular reabsorption occurs Blood supply that directly receives substances from the tubular cells Site that drains the distal convoluted tubule Site of filtrate formation

Site of filtrate formation

If the diameter of the afferent arterioles leading to the glomerulus increases (vasodilation), which of the following is NOT likely to occur? Systemic blood pressure will go up. Net filtration pressure will increase. Urine output will increase. Glomerular filtration rate will increase.

Systemic blood pressure will go up.

What type of response by the afferent arterioles would you expect if blood pressure increased? The afferent arterioles would constrict. The afferent arterioles would dilate

The afferent arterioles would constrict.

Why is the osmolarity of medullary fluid in the kidney almost four times higher than the osmolarity of plasma? The medullary cells in the kidney synthesize solutes to establish the high osmolarity. The nephron loop acts as a countercurrent multiplier and contributes solutes to the interstitial fluid.

The nephron loop acts as a countercurrent multiplier and contributes solutes to the interstitial fluid.

Why is the osmolarity of medullary fluid in the kidney almost four times higher than the osmolarity of plasma? The nephron loop acts as a countercurrent multiplier and contributes solutes to the interstitial fluid. The medullary cells in the kidney synthesize solutes to establish the high osmolarity.

The nephron loop acts as a countercurrent multiplier and contributes solutes to the interstitial fluid.

What role do the vasa recta play in urine formation? The vasa recta create the medullary osmotic gradient. The vasa recta deliver urea to the medullary interstitial fluid The vasa recta protect the medullary osmotic gradient by preventing rapid removal of salt. The vasa recta receive the dilute filtrate from the distal convoluted tubule.

The vasa recta protect the medullary osmotic gradient by preventing rapid removal of salt.

Hydrostatic pressure is the primary driving force of plasma through the filtration membrane into the capsular space. All but one of the following statements reflects why hydrostatic pressure is so high in the glomerular capillaries. Select the one statement that does NOT explain the high pressure within the glomerular capillaries. The diameter of the efferent arteriole is smaller than the afferent arteriole. The flow of blood is reduced as blood reaches the efferent arteriole. The volume of plasma in the efferent arteriole is higher when compared to the afferent arteriole. The efferent arteriole has higher resistance to blood flow than the afferent arteriole.

The volume of plasma in the efferent arteriole is higher when compared to the afferent arteriole.

Annie has just eaten a large order of heavily salted French fries, some pickled eggs, and some cheese. How will consuming this much salt affect her physiology?

There will be a temporary increase in blood volume.

What is the best explanation for the microvilli on the apical surface of the proximal convoluted tubule (PCT)? They increase the amount of surface area that comes in contact with the blood's plasma to help actively excrete toxins. They increase the surface area and allow for a greater volume of filtrate components to be reabsorbed. They hold on to enzymes that cleanse the filtrate before reabsorption. Their movements propel the filtrate through the tubules.

They increase the surface area and allow for a greater volume of filtrate components to be reabsorbed.

The cortex of the kidney has an osmolality of

the same as systemic osmolality

Which of the choices below exerts primary control over sodium levels in the body? glucocorticoids ADH water levels aldosterone

aldosterone

Which of the following hormones acting on the collecting duct is most responsible for retaining sodium ions in the blood? parathyroid hormone atrial natriuretic peptide antidiuretic hormone aldosterone

aldosterone

Which of the following hormones acting on the collecting duct is most responsible for retaining sodium ions in the blood? atrial natriuretic peptide aldosterone parathyroid hormone antidiuretic hormone

aldosterone

ADH added water channels called ________ are essential for water reabsorption in the collecting duct. hydrovesicles aquaporins Na-K pumps fenestrations

aquaporins

Where does primary active transport of sodium occur in proximal convoluted tubule cells? basolateral membrane (outside) apical membrane (inside)

basolateral membrane (outside)

The macula densa cells respond to ________. changes in pressure in the tubule aldosterone changes in Na+ content of the filtrate antidiuretic hormone

changes in Na+ content of the filtrate

The descending limb of the nephron loop ________. pulls water by osmosis into the lumen of the tubule contains fluid that becomes more concentrated as it moves down into the medulla is freely permeable to sodium and urea is not permeable to water

contains fluid that becomes more concentrated as it moves down into the medulla

_______ nephrons specialize in reabsorption and secretion. cortical juxtamedullary

cortical

_______ nephrons specialize in reabsorption and secretion. juxtamedullary cortical

cortical

The ________ creates the medullary gradient and the ________ preserves it.

countercurrent multiplier, countercurrent exchanger

Which of the choices below is NOT a function of the urinary system?

eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat

Reabsorption of nutrients like glucose and amino acids takes place in the proximal convoluted tubule (PCT) via cotransporters. Which of the following would stop the reabsorption of glucose at the apical surface of the cells in the PCT? loss of K+ leak channels at the apical surface increasing Na+ in the interstitial fluid loss of Na+-K+ pumps in the basolateral surface of PCT cells increasing Na+ concentration in the filtrate

loss of Na+-K+ pumps in the basolateral surface of PCT cells

When antidiuretic hormone (ADH) levels are low, ________.

most of the water reaching the collecting ducts is not reabsorbed

The functional and structural unit of the kidneys is the ________. capsular space nephron glomerular capsule nephron loop

nephron

The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________. distal convoluted tubule glomerular filtration membrane collecting duct nephron loop

nephron loop

The primary nephron structure found within the medulla is the ________. PCT glomerular corpuscle nephron loop DCT

nephron loop

In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the ______________________ (the countercurrent multiplier) and the flow of blood through the _________________ (the countercurrent exchanger). This relationship establishes and maintains an osmotic gradient extending from the cortex through the depths of the medulla that allows the kidneys to vary urine concentration dramatically. nephron loop, vasa recta nephron loop, collecting duct collecting duct, nephron loop vasa recta, nephron loop

nephron loop, vasa recta

The ________ creates the medullary gradient and the ________ preserves it. vasa recta, nephron loop nephron loop, vasa recta

nephron loop, vasa recta

Which of the following is NOT a chemical buffer system? protein phosphate nitrogen bicarbonate

nitrogen

Sodium-linked water flow across a membrane not under hormonal control is called ________ water reabsorption. obligatory facultative

obligatory

An older man sees his doctor for severe pain in his lower abdominal or flank area, elevated temperature, and nausea. Exhaustive tests rule out abdominal obstructions and infections. Plain X-rays indicate a radiopaque (whitish) spot in the area of his right ureter. This should be treated with: chemotherapy painkillers and hydration antibiotics insulin to lower blood sugar

painkillers and hydration

Whereas sodium is found mainly in the extracellular fluid, most ________ is found in the intracellular fluid. iron bicarbonate chloride potassium

potassium

Tubular secretion of most unwanted substances occurs in the

proximal convoluted tubule

Aldosterone is a hormone that causes the renal tubules to ___________. secrete sodium ions into the filtrate reabsorb sodium ions out of the filtrate

reabsorb sodium ions out of the filtrate

The filtration membrane includes all EXCEPT ________. glomerular endothelium renal fascia basement membrane podocytes

renal fascia

Which of the following processes in urine formation is important for regulating blood pH? reabsorption secretion filtration

secretion

Extrinsic controls regulate glomerular filtration rate as a means of regulating _______. systemic blood pressure cardiac output urine formation red blood cell production

systemic blood pressure