Tubular reabsorption (10) Flashcards
Is most solute transfer active or passive?
active
Where is the Na/K ATPase found in the kidney?
basolateral membrane of all renal epithelial cells
What are some primary active transport mechanisms found in the kidney>
- Na-K ATPase
- H+ ATPase
- H-K ATPase
What are the two types of secondary active transport?
cotransport and countertransport
What is the most common type of cotransporter?
coupled to inward Na+ gradient
For the driving and driven solutes in cotransport and countertransport, describe the direction of the gradients?
cotransport - opposite gradient directions
countertransport- gradients in the same direction
What are four types of passive transport?
- carrier
- channel
- facilitated diffusion
- simple diffusion
Is paracellular transport active or passive?
passive - driven by transepithelial solute gradient
What is solvent drag?
the movement of solvent contributes the reabsorption or secretion of solutes
comparable to a stream
What does this describe: transcellular reabsorption and secretion is saturable at a maximum rate
Tmax
How do you calculate the amount of reabsorbed glucose?
Plasma concentration x GFR - Urine concentration x Flow of urine
how much glucose is found in the urine?
usually none
As glucose concentration increases, what happens to the filtered load?
it increases linearly
As glucose becomes saturated in the kidney, what happens?
excretion begins to occur
What disease does saturation of glucose, and therefore excretion occur in?
diabetes mellitus
