Organ
Loop of Henle
Tubular limbs with contrasting transport properties
High-yield
NKCC2 moves sodium, potassium and chloride into thick ascending-limb cells. This segment reabsorbs salt while remaining poorly permeable to water, diluting the tubular fluid.
Overview
The nephron loop carries fluid toward the medulla and then back toward its glomerulus. Descending thin segments generally allow substantial water movement, whereas ascending segments recover salt with little water. Combined with collecting-duct and vascular processes, this helps establish the kidney's concentrating system.
Reference facts
- Location
- Loops turn at different depths: short cortical-nephron loops mainly in outer medulla, and long juxtamedullary loops deeper toward the papilla.
- Parts
- Thin descending limb, a thin ascending limb in long loops, and thick ascending limb returning toward the macula densa; permeability differs by segment.
- Blood supply
- Medullary portions lie alongside the vasa recta, while cortical portions have cortical microvascular support.
- Innervation
- Renal sympathetic activity influences both tubular salt transport and associated vascular perfusion.
- Function
- Contributes to the corticomedullary osmotic gradient and reabsorbs a substantial salt load, including much filtered magnesium and some calcium.
Clinical correlation
Loop diuretics inhibit NKCC2 and reduce salt recovery and concentrating capacity. Bartter syndromes involve defects in several thick-limb transport proteins; only some forms are caused by NKCC2 mutations.
Frequently asked questions
Where is the loop of Henle located?
Loops turn at different depths: short cortical-nephron loops mainly in outer medulla, and long juxtamedullary loops deeper toward the papilla.
What does the loop of Henle do?
Contributes to the corticomedullary osmotic gradient and reabsorbs a substantial salt load, including much filtered magnesium and some calcium.
What are the parts of the loop of Henle?
Thin descending limb, a thin ascending limb in long loops, and thick ascending limb returning toward the macula densa; permeability differs by segment.
What is the blood supply of the loop of Henle?
The loop of Henle is supplied by the medullary portions lie alongside the vasa recta, while cortical portions have cortical microvascular support.