SECRETION AND REABSORPTION: PCT

Reabsorption ______ useful substances that could be lost after they have been filtered back to the _____

returns, body

Secretion is the _______ of waste products into the kidney ________.

ejection, tubule

Substances can either sneak through tight ______ or have a two-step process to pass completely through the simple cuboidal _______ cells from the apical surface to the basolateral.

junctions, epithelial

What type of substances are REABSORBED?

1) glucose 2) simple sugars 3) ions 4) lipid soluble substances 5) water

What type of substances are SECRETED?

1) NH3+ (ammonium) 2) H+ 3) creatinine 4) drugs 5) toxins

Sodium can move through a ___________ reabsorption (between cells) or a ____________ reabsorption (through the cell)

paracellular, transcellular

Transcellular reabsorption of sodium requires two transporters: one at the _____ surface and one at the _________ surface.

apical, basolateral

Transcellular transport mechanism for sodium at the basolateral surface is ________ - __________ ATPase and apical transport will typically be a ________ _____ transport process.

sodium, potassium, secondary, active

Secondary active transport mechanisms at the apical surface either ________ a substance into the cell along with sodium (i.e. glucose) or ________ something out of the cell at the same time sodium moves in (i.e. H+).

symport, antiport

Substances leaving the epithelial cells at the basolateral surface exit via ________ transport mechanisms and the basolateral side is where the ______ - ________ ATPase resides.

passive, sodium, potassium

Water follows substances that move across the epithelial membrane of the kidney tubule, what is this process called?

solvent drag

Mechanism of Glucose Reabsorption (1): Glucose is cotransported through a _______ _____ transport process with ______ into the epithelial cell at the ______ membrane.

secondary, active, sodium, apical

Mechanism of Glucose Reabsorption (2): Glucose leaves the epithelial cell by process of ________ ________ mechanism (passive) on the ________ side.

facilitated diffusion, basolateral

Mechanism of Glucose Reabsorption: During this mechanism sodium moves _____ its concentration gradient while glucose moves ______ its concentration gradient.

down, against

There is a maximal rate of transport of solutes in the kidney tubules because transport of solute to the epithelial cells is mediated by _______ proteins; at the maximum, all of them are occupied

carrier

Inability to remove glucose from the filtrate in response to all carrier proteins being occupied, glucose shows up in the ____; this problem would be indicative of ________

urine, diabetes

Na+ reabsorption and H+ Secretion (1): Hydrogen ion is exported ____ the kidney tubule _______ its concentration gradient through a ________ (secondary-active transport) mechanism at the apical surface.

into, against, antiport

Na+ reabsorption and H+ Secretion (2): When the hydrogen ion is inside the epithelial cell—before being secreted into the tubular fluid—it is a product of the _______ _______ equation

carbonic anhydrase

Na+ reabsorption and H+ Secretion (3): The carbon dioxide that helps drive the carbonic anhydrase reaction to produce a hydrogen ion can simply diffuse from two places or reside in the third. What are these three places?

1) tubular fluid 2) the body 3) the cell itself as a byproduct of cellular respiration

Na+ reabsorption and H+ Secretion (3): Bicarbonate product generated in the carbonic anhydrase reaction leaves the cell via ________ ______ at the _________ surface and reenters the body.

facilitated diffusion, basolateral