Renal 4

Question 1

High capacity & variable; very selective
Many electrolytes and nutrients almost completely reabsorbed
Most waste products poorly reabsorbed.

Answer 1

Tubular reabsorption

Question 2

Variable

Important for certain electrolytes (K+, H+), drugs, toxins.

Answer 2

Tubular Secretion

Question 3

How much of urea is reabsorbed?

Answer 3

50%

Question 4

How much of creatinine is reabsorbed?

Answer 4

0%

Question 5

Once fluid is reabsorbed across the tubule epithelium into the interstitial fluid, it enters _____ via Bulk Flow

Answer 5

peritubular capillaries

Question 6

Once fluid is reabsorbed across the tubule epithelium into the interstitial fluid, it enters peritubular capillaries via _____

Answer 6

Bulk Flow

Question 7

The peritubular capillary and renal interstitial fluid favors filtration or reabsorption?

Answer 7

Reabsorption

Question 8

Normal rate of Peritubular Capillary Reabsorption is ____ ml/min

Answer 8

124 ml/min

Question 9

What is the normal GFR in ml/min?

Answer 9

125 ml/min

Question 10

Which Starling’s force is the largest in the peritubular capillary and renal interstitial fluid physical forces?

Answer 10

Capillary colloid osmotic pressure

Question 11

How much of filtered sodium is reabsorbed?

Answer 11

> 99%

Question 12

Sodium Reabsorption can occur via both ____ and ______

Answer 12

Transcellular and Paracellular

Question 13

Transcellular pathways-Passive across ____ membrane and active across _____ membranes

Answer 13

apical; basolateral

Question 14

_____ membrane Na+ transport may be secondary active and tied to reabsorption of other substance

Answer 14

Apical membrane

Question 15

Maximum rate some substances can be transported across the epithelium (absorption or secretion)
Due to saturation of transport proteins

Answer 15

Transport Maximum

Question 16

______- is the plasma concentration that saturates the carrier (tubular load)

Answer 16

Renal Threshold

Question 17

Once the ______ is reached for all nephrons, further increases in tubular load are not reabsorbed and are excreted.

Answer 17

transport maximum

Question 18

As [Glucose]plasma increases, the [Glucose]filtrate ______, Glucose tubular load _______.

Answer 18

increases; increases

Question 19

Reabsorption of Water is strictly active or passive?

Answer 19

Passive

Question 20

As ___ reabsorbed, creates gradient for H2O reabsorption via osmosis

Answer 20

Na+

Question 21

Which segment of the nephron is highly permeable to H2O?

Answer 21

Proximal tubule

Question 22

As H2O moves via osmosis:-Carries other solvents along called _____

Answer 22

Solvent drag

Question 23

T/F: As H2O moves via osmosis, creates gradients for the passive reabsorption of other solute (ex. Cl- and Urea)

Answer 23

true

Question 24

H2O Permeability ____ as move through nephron

Answer 24

varies

Question 25

What is the permeability of H20 in the Ascending limb of Loop of Henle?

Answer 25

(not permeable to H2O)

Question 26

What is the permeability of H20 in the Collecting duct?

Answer 26

(regulated by ADH)

Question 27

PT Reabsorption of Na+, Cl-, Urea and H2O exhibit ______ Transport

Answer 27

Gradient-Time

Question 28

Increased time a substance is in the lumen causes there to be more rabsorbtion

Answer 28

Gradient-Time Transport

Question 29

The concentrations of solutes in different parts of the tubule depend on relative reabsorption of the solutes compared to ______

Answer 29

water

Question 30

if water is reabsorbed to a greater extent than the solute, the solute will become ______ concentrated in the tubule

Answer 30

More concentrated

Question 31

if solute is reabsorbed to a greater extent than water, the solute will become ______ concentrated in the tubule

Answer 31

Less concentrated

Question 32

Cells have High capacity for Active and Passive Reabsorption -Large # mitochondria -Large surface area on both apical and basolateral membranes -Large number of membrane proteins -High permeability for H2O.

Answer 32

Proximal tubule

Question 33

Reabsorbs –~ 65% of filtered Na+, Cl-, HCO3-, and K+ – All filtered glucose and amino acids.

Answer 33

Proximal tubule

Question 34

Secretes - metabolic waste products such as H+ ions , organic acids, and bases such as: bile salts, oxalate, urate, and catecholamines - Harmful drugs or toxins - Para-Aminohippuric Acid (PAH)

Answer 34

Proximal tubule

Question 35

_____ and ______ - Isotonic Solution Reabsorbed

Answer 35

Na+ and H2O

Question 36

Distal Portion of proximal tubule reabsorbs more ____ and ____

Answer 36

Cl- and urea

Question 37

______ of proximal tubule not actively reabsorbed

Answer 37

Creatinine

Question 38

____ inhibitors used in treatment of T2DM

Answer 38

SGLT2

Question 39

What is the Na and Glucose symporter on the lumen in the early PT?

Answer 39

SGLT2

Question 40

What is the Glut transporter is on the basolateral in the early PT?

Answer 40

GLUT2

Question 41

______: Cl reabsorption Paracellularly Passive down ΔEC Solvent drag

Answer 41

Early PT

Question 42

``` ______: Cl absorption Transcellular Apical 2° active Formate/Cl- antiporter Basolateral facilitated diffusion Paracellularly ```

Answer 42

Late PT

Question 43

High H2O permeability (Contain AQP-1 channels): major role in concentration/dilution of urine No active solute transport Urea secretion via facilitated diffusion

Answer 43

Thin Descending Limb (tDL)

Question 44

does not reabsorb significant amounts of any solutes impermeable to water Urea secretion via facilitated diffusion

Answer 44

Thin Ascending limb (tAL)

Question 45

Impermeable to H2O and Urea Major site of Na+, K+, Cl- reabsorption, H+ secretion By end of Loop of Henle, more solute reabsorbed than H2O Distal End of TAL forms part of JG apparatus

Answer 45

Thick Ascending Limb (TAL)

Question 46

``` Parallels TAL in that it absorbs solute w/out H2O Impermeable to H2O (and urea). Reabsorbs ions -5% of Na+ & Cl- –Further dilutes filtrate –Diluting Segment ```

Answer 46

Early Distal tubule

Question 47

Na+-Cl-co-transporter in apical membrane moves Na+ and Cl-into cells from tubule lumen Na+-K+-ATPase transports Na+into interstitium. Cl- diffuses into the interstitium through channels in basolateral membrane.

Answer 47

Early Distal tubule

Question 48

What are the 2 cell types of the Late distal/ cortical collecting duct?

Answer 48

Principal cells and intercalated cells

Question 49

Principal cells and intercalated cells are part of what segment of the nephron?

Answer 49

Late distal/ cortical collecting duct

Question 50

60-70% of cells Site of Aldosterone and ADH action –Reabsorb Na+ and H2O –Secrete K

Answer 50

Principal cells

Question 51

Late distal/ cortical collecting duct are completely impermeable to _____.

Answer 51

Urea

Question 52

Function important during acidosis Secrete H+ Reabsorb K+ and HCO3- 1° Active Transport of H+across apical membrane can secrete H+against a great ΔC (1000:1)

Answer 52

Alpha Intercalated Cells

Question 53

Function important during alkalosis Secrete K+ and HCO3- Reabsorb H+

Answer 53

Beta Intercalated Cells

Question 54

Which intercalated cells secrete acids?

Answer 54

Alpha secretes acids

Question 55

Which intercalated cells secrete bases?

Answer 55

Beta secretes bases

Question 56

Processes < 10% of Na+ and H2O but very important (10% of 180 L). Site of Aldosterone and ADH action Urea reabsorbed via facilitated diffusion Secretes H+ using same mechanism as α-intercalated cells.

Answer 56

Medullary Collecting Duct (MCD)