TOPIC 9

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Biology Concept Map #2

Ved Omar Escalante

INTEREST

Ved DAVIDE ROCCO

Who Am I Hobbies and Interests

Ved Kha Raymond

Pharmacology of emergency medications

Ved Juan Longoria

TOPIC 9

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Aquaporin 2

Collecting Duct

RAAS and ADH Systems

ADH/Vasopressin

Regulation

Antidiuresis: low urine flow rate

U/P > 1

stimulated by high plasma osmolarity

high urine osmolarity

Diuresis: high urine flow rate (unable to retain water)

U/P < 1

stimulated by low plasma osmolarity

low urine osmolarity

Increase plasma osmolarity, increase plasma vasopressin

Comes from the blood stream

Helps us increase BP by increasing water reabsroption.

Stimulates aquaporin translocation into collecting duct of apical membranes

Loop of Henle

Descending vs Ascending

Ascending

Thick: NaKCl cotransporter 2 (NKCC2) absorbs NaCl. Gap junctions are leaky and allow Na+ to slip through

Thin: Na and Cl are transported actively out of tubule (movement of solutes out = lower osmolarity = hypoosmotic fluid)

Descending

Water moves out to concentrate fluid

Water permeable (moves out of tubules because of hyperosmotic medulla)

Thick medulla allows increased urine osmolarity

Thicker medulla --> longer loops --> more concentrated urine --> more reabsorption of water

Medulla osmotic gradient determines max urine osmolarity

Extension of the loop

The longer the papilla, the longer the loop

Aquatic species have the shortest papilla (don't need to conserve as much water because live in water)

Mesic species (land/terrestrial) have an "average" papilla (have regular access to water)

Arid species have the longest papilla (need to conserve as much as possible because little access to water)

Dips down into medulla (where peritubular capillaries/vasa recta are located)

Loops allow fluid to be edited by environment of kidney