Loop of Henle

• Loop of Henle wall is one cell thick; thinner and thicker regions of loop reflect differences in lumen diameter, and different regions have different permeabilities to water, sodium and chloride ions

  A) permeable

  B) aquaporins

  C) impermeable

  D) permeable

  E) permeable

  F) facilitated

  G) active

  H) permeable

  I) permeable

  J) facilitated

  K) active

  
• Each nephron has a Loop of Henle in medulla region; they lie very close to collecting ducts and vasa recta (capillary network) that lie adjacent to each Loop of Henle
• Increased salt concentration lowers medulla water potential; more water reabsorbed from filtrate in collecting ducts, this enters vasa recta blood capillaries; crucial for terrestrial mammal water conservation, urine is hypertonic to blood plasma
• Countercurrent multiplier system: Loop of henle hairpin arrangement (two limbs are close), fluid flows in opposite directions; longer loop has greater countercurrent multiplier effect
• Loop of Henle

  A) tubule

  B) H_2O

  C) sodium

  D) chloride ions

  E) Descending

  F) Na^+

  G) Cl^-

  H) water

  I) Descending

  J) osmosis

  K) capillaries

  L) H_2O

  M) Na^+

  N) Cl^-

  O) sodium

  P) chloride ions

  Q) Ascending

  R) Na^+

  S) Cl^-

  T) Na^+

  U) Cl^-

  V) active removal

  W) sodium

  X) chloride

  Y) Ascending

  Z) Distal convoluted tubule

  [) cortex

  \) Medulla

  ]) collecting duct

  ^) H_2O

  _) collecting duct

  `) osmosis

  a) capillaries

  b) H_2O

  c) urine

  d) collecting duct

  e) pelvis