Physiology 4 and 5

Question 1

What is the major site of reabsorption in the kidney?

Answer 1

proximal tubule

Question 2

What osmolality does the fluid reabsorbed in the proximal tubule have?

Answer 2

iso-osmotic with filtrate

Question 3

What is reabsorbed in the proximal tubule?

Answer 3

sugars; amino acids; phosphate; sulphate; lactate

Question 4

What primary active transport?

Answer 4

ATP dependent

Question 5

What is secondary active transport?

Answer 5

carrier molecule is transported coupled to a conc. grad of an ion

Question 6

What is facilitated diffusion?

Answer 6

passive carrier-mediate transport of a substance down its conc. grad.

Question 7

What transport mechanism is essential for sodium reabsorption?

Answer 7

Na/K ATPase at hte basolateral membrane

Question 8

What are amino acids and glucose tranported with?

Answer 8

sodium- secondary active transport

Question 9

What other substance does couple with in a transport?

Answer 9

hydrogen- but the other way- countertransport

Question 10

What ion does the high conc. of sodium in the interstitial fluid attract?

Answer 10

chloride

Question 11

what does NaCl pull down an osmotic gradient into the interstitial fluid?

Answer 11

water

Question 12

What pulls the water into the blood?

Answer 12

oncotic drag of peritubular plasma (plasma proteins)

Question 13

What is Tm?

Answer 13

transport maximum- transport systems involved in reabsorption and secretion are saturable

Question 14

What is the function of the loop of Henle?

Answer 14

generates a cortico-medullar solute concentration gradient to enable the formation of hypertonic urine

Question 15

What is the opposing flow in the 2 limbs of the loop called?

Answer 15

countercurrent flow

Question 16

What happens in the ascending limb?

Answer 16

sodium and chloride are being reabsorbed, realtively impermeable to water

Question 17

What happens in the descending limb?

Answer 17

does not reabsorb NaCl and is highly permeable to water

Question 18

Waht is the tranporter found inthe ascending loop of Henle?

Answer 18

sodium/potassium/chloride co-transporter

Question 19

What is the difference in solute between the descending limb and ascending limb?

Answer 19

descending-loses water so osmolality increases; ascending limb loses ions so osmolality decreases

Question 20

What is concurrent mulitplication?

Answer 20

where a steady state has been reached where the water passively flowing down the osmotic gradient in response to solute pumped out of ascending limb

Question 21

What type of fluid is found entering the distal convoluted tubule?

Answer 21

hypoosmotic fluid

Question 22

What otehr substance contributes to medullar osmolality?

Answer 22

urea

Question 23

What is the purpose of countercurrent mulitplication?

Answer 23

to enable kidney to produce urine of different bolume and concentration according to the amounts of ADH

Question 24

What runs along side the long loop of Henle of juxtaglomedullary nephorns?

Answer 24

vasa recta

Question 25

What do the vasa recta act as?

Answer 25

countercurrent exchanger

Question 26

What happens to the vasa recta as a result of their leaky endothelium?

Answer 26

capillary blood equilibrate with interstitial fluid- so that sodium chloride and urea arent washed away- floows the pattern of the nephron—preserves medullary gradeint