human phys renal countercurrent mech acid base baalcne electrolyte disord final exam

kidney

reg water balance

filtrate

initally resembles plasma

urine concentration

req osmotic gradient

ggradient

exists in renal medulla

gen by countercurrent mechanism

strucutre of loop of henle

descending limb

ascending limb

descending limb

permeable to water

ascending limb

imperm to water

perm to Na k cl

loop of henle

create osmotic diff

basis of countercurrent multiplicaton

descening and ascending limbs

oppositie flow

solute transport

ascendign limb

water movement

descending llimb

countercurrent multiplicaiton

establishes medullary osmotic gradient

enables urine concentration

role of vasa recta

specialized peritubular capillaries

run parallel to loops of henle

maintain medullary osmotic gradient

operate via countercurrent exchange

prevent gradient washout

kidney

reg hydrogen and bicarbonate

compliment respiratory reg

acid base balance

important in metabolic distrubances

essentail for enzyme and cellular function

bicarbonate reabosorption

in proximal tubule

involves H secretion

reclaims filtered bicarbonate

prevents bicarbonate loss in urine

carbonic anhydrase

catalyzes bicarbonate reabsorption

hydrogen ion secretion

occurs in distal nephron

uses proton pumps and exchangers

gen new bicarbonate

crtical for acid excretion

maintain blood pH

kideny

reg na k cl and other

transport

occurs along nephron segments

electrolyte balance

controlled by hormones

maintains plasma osmolarity

esential fo rcellular function

hyperkalemia

excess K

hypokalemia

low K

kidney

reg K excretion

K disorder

changes affect cardiac excitability

linked to renal dysfunction