Chapter 27: Urine Formation By The Kidneys II

Question 0

Transport of water and solutes through the cell membranes themselves

Answer 0

Transcellular route

Question 1

Both Glomerular Filtration and Tubular Reabsorption are non-selective. True or False

Answer 1

False. GF is mon-selective. TR is highly selective

Question 2

Transport of water and solutes through the spaces between the cell junctions

Answer 2

Paracellular route

Question 3

Mechanism by which water and solutes are transported through the peritubular capillary walls into the blood mediated by hydrostatic snd colloid osmotic forces

Answer 3

Ultrafiltration (bulk flow)

Question 4

Transport coupled directly to an energy source such as hydrolysis of ATP

Answer 4

Primary active transport

Question 5

Transport coupled indirectly to an energy source, such as due to an ion gradient

Answer 5

Secondary active transport

Question 6

4 Primary active transporters of the kidneys

Answer 6

Na-K ATPase
H ATPase
H-K ATPase
Ca ATPase

Question 7

Secondary active transporters in the kidneys

Answer 7

Na-Glucose co-transporters (SGLT1 & SGLT2)
Na-amino acid co-transporters
Na-H exchanger
1-Na, 2-Cl, 1-K co-transporter

Question 8

Reabsorption of large molecules such as proteins occurs through which mechanism?

Answer 8

Pinocytosis

Question 9

Refers to the limit to the rate at which the solute can be transported. This is due to the saturation oft he specific transport systems involved when the tubular load exceeds the capacity of the carrier proteins and specific enzymes involved in the transport process.

Answer 9

Transport maximum

Question 10

Refers to the amount of solute delivered to the tubule

Answer 10

Tubular load

Question 11

Process by which water carries some of the solutes as it moves across the tight junctions by osmosis

Answer 11

Solvent drag

Question 12

Hormone that greatly increases the water permeability in the distal and collecting tubules

Answer 12

ADH

Question 13

2 Methods by which Cl is reabsorbed

Answer 13

Passive diffusion (paracellular pathway)
Co-transport with sodium

Question 14

Percentage of the filtered load of sodium and water reabsorbed by the proximal tubule

Answer 14

65%

Question 15

2 cellular characteristics giving proximal tubules high capacity for reabsorption

Answer 15

Highly metabolic and have Large numbers of mitochondria

Extensive brush border loaded with protein carrier molecules

Question 16

Sodium reabsorption in the first half of the proximal tubule occurs through which mechanism?

Answer 16

Co-transport of Na with glucose, aa, bicarbonate, organic ions

Question 17

Sodium reabsorption in the second half of the proximal tubule occurs through which mechanism?

Answer 17

Co-transport with Cl ions

Question 18

Portion of the loop of Henle which is permeable to water.

Answer 18

Thin descending limb

Question 19

Transporters in the thick ascending limb of the loop of Henle

Answer 19

Na-K ATPase in the basolateral membrane
1-Na, 2-Cl, 1-K co-transporter in the luminal membrane
Na-H counter-transport

Question 20

Site of action of loop diuretics

Answer 20

Thick ascending limb of the loop of Henle

Question 21

Otherwise known as the diluting segment as it avidly reabsorbs most of the ions but is virtually impermeable to water and urea

Answer 21

Second part of the early distal tubule

Question 22

Site of action of thiazide diuretics

Answer 22

Na-Cl co-transporter in the early distal tubule

Question 23

Action of principal cells

Answer 23

Na reabsorption and K secretion by Na-K ATPase in the basolateral membrane

Question 24

2 distinct cells in the late distal tubule and cortical collecting tubule

Answer 24

Principal cells

Intercalated cells

Question 25

Site of action of potassium-sparing diuretics

Answer 25

Principals cells

Aldosterone antagonists on Na-K ATPase
Sodium channel blockers on Na channel

Question 26

Action of Intercalated cells

Answer 26

Hydrogen secretion H-ATPase and H-K ATPase

Bicarbonate and Potassium reabsorption

Question 27

Vasopressin controls the permeability of which tubular segments

Answer 27

Late distal tubule and collecting ducts

Question 28

Final site for processing urine and plays a role in determining final urine output of water and solutes

Answer 28

Medullary collecting duct

Question 29

Used to estimate renal plasma flow

Answer 29

Para-aminohippuric acid clearance

Question 30

Polysaccharide used to measure GFR

Answer 30

Inulin

Question 31

Intrinsic ability of tubules to increase their reabsorption rate in response to increased tubular load. It also acts as second line of defense to buffer the effects of spontaneous changes in GFR and urine output.

Answer 31

Glomerulotubular balance

Question 32

Determinants of reabsorptive force

Answer 32

Peritubular hydrostatic pressure
Peritubular capillary colloid osmotic pressure
Renal interstitial hydrostatic pressure
Renal interstitial colloid osmotic pressure

Question 33

Effect of afferent and efferent arteriolar constriction on peritubular capillary reabsorption

Answer 33

Increased reabsorption due to decreased peritubular capillary hydrostatic pressure

Question 34

Effect of decreased renal plasma flow on reabsorption

Answer 34

Increased reabsorption. Dec renal plasma flow –> inc filtration fraction –> inc colloid osmotic pressure

Question 35

Small increases in arterial pressure causes pressure natriuresis and pressure diuresis. Give 3 events that lead to this.

Answer 35

• increased GFR
• increased peritubular capillary hydrostatic pressure
• reduced angiotensin II formation

Question 36

Cells that secrete Aldosterone

Answer 36

Zona glomerulosa cells oft he adrenal cortex

Question 37

Body’s most powerful sodium-retaining hormone

Answer 37

Angiotensin II

Question 38

3 main effects of angiotensin II

Answer 38

• aldosterone secretion
• efferent arteriolar constriction
• directly stimulates Na reabsorption on Na-K ATPase pump on the basolateral membrane, Na-H exchanger in the luminal membrane and Na-HCO3 co-transporter in the basolateral membrane

Question 39

Effect of parathyroid hormone on tubular reabsorption

Answer 39

Inc calcium reabsorption in the distal tubules and loops of Henle
Dec phosphate reabsorption in the proximal tubule
Magnesium reabsorption in the loop of Henle

Question 40

Effect of SNS activation on sodium and water

Answer 40

Increased reabsorption through:

• decreased excretion d/t renal arteriolar constriction
• increased renin release and agiotensin II formation