The descending limb of the loop of Henle forms the initial part of the loop of Henle which helps in maintaining the urine concentration. It is entirely impermeable to the sodium and chloride ions but it is permeable to the water which accounts for reabsorption of water from this tubule through osmosis.

Which limb of the nephron loop is impermeable to sodium?

The loop has a sharp bend in the renal medulla going from descending to ascending thin limb. The thin ascending limb is impermeable to water, but it is permeable to ions. Sodium (Na⁺), potassium (K⁺) and chloride (Cl⁻) ions are reabsorbed from the urine by secondary active transport by a Na-K-Cl cotransporter (NKCC2).

Which part of nephron is impermeable to?

Ascending limb of loop of Henle is impermeable to water. Here water is not reabsorbed, rather sodium, potassium, magnesium and chloride are reabsorbed and therefore the filtrate becomes hypotonic to blood plasma.

Which component of the nephron is impermeable to NaCl?

Sodium is actively pumped out, while potassium and chloride diffuse down their electrochemical gradients through channels in the tubule wall and into the bloodstream. The walls of the thick ascending limb are impermeable to water, so in this section of the nephron water is not reabsorbed along with sodium.

Which site in the kidney is impermeable to NaCl?

Summary. The ascending thin limb of Henle's loop has been one of the most mysterious nephron segments because of the unique characteristics of its NaCl and water transport systems. The ascending thin limb is essentially impermeable to water under all circumstances.

Where in the nephron is sodium reabsorbed?

33 related questions found

Why is ascending loop of Henle impermeable?

The ascending limb (where loop diuretics work) is impermeable to water. NaCl is pumped from the tubule into the interstitium in the ascending limb. The tubular osmolarity decreases and fluid that leaves the loop is hypotonic. The collecting duct is impermeable to water without ADH.

Where is Na+ reabsorbed in the nephron?

Sodium is reabsorbed in the thick ascending limb of loop of Henle, by Na-K-2Cl symporter and Na-H antiporter.

Which part of loop of Henle is impermeable to water?

The descending limb of loop of Henle is impermeable to both water and electrolytes.

Where are podocytes present?

Podocytes are found lining the Bowman's capsules in the nephrons of the kidney. The foot processes known as pedicels that extend from the podocytes wrap themselves around the capillaries of the glomerulus to form the filtration slits.

What is Henle's loop?

loop of Henle, long U-shaped portion of the tubule that conducts urine within each nephron of the kidney of reptiles, birds, and mammals. ... This function allows production of urine that is far more concentrated than blood, limiting the amount of water needed as intake for survival.

Which region of the nephron tubule is impermeable to h2o?

The ascending loop of Henle is impermeable to water but permeable to salt.

Which of the following portions of the nephron is highly impermeable to water?

Descending limb of loop of Henle.

What is impermeable to water?

Clay, shale and slate are rocks that do not allow water to pass through and are therefore classified as impermeable. Unlike permeable rocks that absorb water, impermeable rocks can support and change the beds of rivers and streams, are prone to erosion, and can prevent the flow of groundwater.

Does ADH effect loop of Henle?

The loop of Henle establishes a salt gradient (hypertonicity) in the medulla. Anti-diuretic hormone (ADH) regulates the level of water reabsorption in the collecting duct.

What happens to sodium and chloride in the ascending limb of the Henle loop?

Thick ascending limbs of Henle's loop have at least three major roles: (1) They reabsorb sodium chloride which dilutes the urine. ... (3) They reabsorb large amounts of potassium, calcium, and magnesium in an energy-efficient manner.

What is happening in the loop of Henle?

This part of the nephron is called the loop of Henle. Its main function is to reabsorb water and sodium chloride from the filtrate. This conserves water for the organism, producing highly concentrated urine.

Where are podocytes found in the kidney?

Podocytes are highly specialized epithelial cells in the visceral layer of the kidney Bowman's capsule (glomerulus) attached to the basement membrane of the capillaries via cytoplasmic pedicles (footlike projections).

Why do podocytes not undergo mitosis?

The podocytes are arrested at G₀ of the cell cycle. If podocytes frequently underwent mitosis, it would alter the number and therefore the size of the fenestrations on the Bowman's capsule, changing the ultrafiltration rate.

What is the role of podocytes in the nephron?

Podocytes play an important role in glomerular function. Together with endothelial cells of the glomerular capillary loop and the glomerular basement membrane they form a filtration barrier. Podocytes cooperate with mesangial cells to support the structure and function of the glomerulus.

Which part of the nephron is almost impermeable to electrolytes?

The descending limb of loop of Henle is permeable to water but almost impermeable to electrolytes. This concentrates the filtrate as it moves down. The ascending limb is impermeable to water but allows transport of electrolytes actively or passively.

Which limb of loop of Henle is impermeable to electrolytes?

Descending limb of loop of Henle is permeable to water but impermeable to electrolytes while ascending limb is impermeable to water but permeable to electrolytes.

Which section of the nephron is after the ascending limb of the loop of Henle?

The turn of the loop of Henle usually occurs in the thin segment within the medulla, and the tubule then ascends toward the cortex parallel to the descending limb. The end of the loop of Henle becomes the distal convoluted tubule near its original glomerulus.

How is Na+ reabsorbed?

Na+ is reabsorbed by active transport using ATP. Most of the energy used for reabsorption is for Na+. Major calyces are: ... Major calyces are the large branches of the renal pelvis.

How does kidney excrete sodium?

Renal Regulation of Sodium Excretion Function in Health and in Edema-Forming States. From the Renal Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis. Urinary sodium excretion could be regulated through changes in glomerular filtration rate (GFR) or sodium reabsorption.