COUNTERCURRENT EXCHANGE

kidneys ________ volume and water; they _______ replace lost volume.

kidneys, cannot

Kidneys regulate internal pH by secreting ___ and _____ as needed.

H+, HCO3-

Water reabsorption is under the control of ____ in its absence very little water will be recaptured resulting in ____ urine.

ADH, dilute

The DESCENDING LIMB of the Loop is ___________ to water BUT relatively ___________ to solutes.

permeable, impermeable

The ASCENDING LIMB of the Loop is ____________ to water BUT is ____________ to solutes (Na+/Cl-) through the NKCC transporter mechanism.

impermeable, permeable

Urea ___________ contributes to the medullary osmotic gradient.

recycling

Fluid in the distal convoluted tubule is ____ concentrated than the fluid in the proximal convoluted tubule

less

The countercurrent exchange is a ______ feedback loop.

positive

Urea can move OUT the _______ ____ by process of ________ moving INTO the _______ limb of the loop of Henle.

collecting duct, diffusion, ascending