Water Reabsorption Process in Cells

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What is the aid in water reabsorption through the plasma membrane?

Tight junctions

Osmolality gradients

Aquaporins (correct)

Presence of sodium ions

What is the result of increasing interstitial osmolarity?

Sodium ion reabsorption

Water diffusion out of the tubular lumen (correct)

Water diffusion into the tubular lumen

Increased sodium ion secretion

What is the primary function of the proximal convoluted tubule?

Sodium ion reabsorption

Water reabsorption

Reabsorption of valued substances (correct)

Filtrate processing

What is the primary mechanism of water reabsorption in the nephron?

Diffusion through aquaporins Signup and view all the answers

What is the result of sodium ion transport in the nephron?

Increased reabsorption of substances Signup and view all the answers

What is the purpose of the basalateral membrane in the proximal convoluted tubule?

Enables active transport of sodium ions Signup and view all the answers

What is the significance of sodium ion reabsorption in the nephron?

Enables reabsorption of valued substances Signup and view all the answers

What is the role of tight junctions in the nephron?

Permits diffusion of water and solutes Signup and view all the answers

What is the main function of the high osmolarity of the medullary interstitium?

To pull water out of the filtrate Signup and view all the answers

What is unique about the cells in the thin descending loop of Henle?

They lack transport proteins Signup and view all the answers

What happens to the filtrate as it passes down the thin descending loop of Henle?

It becomes more concentrated Signup and view all the answers

What is unique about the luminal membrane of cells in the ascending loop of Henle and early DCT?

It has a glycoprotein layer and tight junctions Signup and view all the answers

What is the function of the secondary active transport molecule in the ascending loop of Henle and early DCT?

To cotransport potassium and chloride Signup and view all the answers

What happens to the potassium ions that are imported into the cells of the ascending loop of Henle and early DCT?

They diffuse back into the filtrate Signup and view all the answers

What is present in the basolateral membrane of cells in the ascending loop of Henle and early DCT?

Sodium/potassium ATPase ion pumps and potassium channels Signup and view all the answers

What is the result of the reabsorption of water in the thin descending loop of Henle?

The filtrate becomes more concentrated Signup and view all the answers

What is the primary function of the ascending limb in the Loop of Henle?

To actively transport sodium chloride into the interstitium, increasing its concentration Signup and view all the answers

What happens to the filtrate as it moves down the descending limb?

It becomes more concentrated as water diffuses into the tubule Signup and view all the answers

What is the concentration of solutes in the filtrate at the bottom of the loop?

Approximately four times greater than normal body fluid Signup and view all the answers

What is the role of the descending limb in the Loop of Henle?

To provide a continuous, concentrated supply of sodium chloride to the ascending limb Signup and view all the answers

What is the role of the sodium/potassium ATPase ion pump in the basolateral membrane?

Primary active transport of sodium ions out of the cell and potassium ions into the cell Signup and view all the answers

What is the result of the sodium/potassium ATPase ion pump yielding its energy?

ATP is converted to ADP and an inorganic phosphate ion Signup and view all the answers

What is the result of the ascending limb's active transport of sodium chloride into the interstitium?

The interstitium becomes more concentrated, and the fluid inside the tubule becomes more dilute Signup and view all the answers

What is the purpose of the osmotic gradient created by the ascending limb?

To maintain the osmotic gradient necessary for the countercurrent multiplier mechanism Signup and view all the answers

What is the function of the glucose carrier molecule in the basolateral membrane?

To transport glucose across the basolateral membrane by a passive mechanism called facilitated diffusion Signup and view all the answers

What is the role of the potassium ion channel in the basolateral membrane?

To prevent potassium ion depletion in the blood or excess accumulation Signup and view all the answers

What is the relationship between the activity of the transport proteins in the luminal membrane and the sodium/potassium ATPase ion pump activity in the basolateral membrane?

The activity of the transport proteins in the luminal membrane depends on the sodium/potassium ATPase ion pump activity Signup and view all the answers

What type of transport does the glucose carrier molecule use to transport glucose across the basolateral membrane?

Facilitated diffusion Signup and view all the answers

What is the direction of glucose movement across the basolateral membrane when its concentration is highest in the cell?

Out of the cell into the interstitium Signup and view all the answers

What type of transport is responsible for carrying out the sodium/potassium ATPase ion pump's function?

Active transport Signup and view all the answers

What is the primary function of intercalated cells in the late distal convoluted tubule and collecting ducts?

Secreting hydrogen ions into the filtrate to balance blood pH Signup and view all the answers

What is the role of aldosterone in the late distal convoluted tubule and collecting ducts?

Precise regulation of the final amount of sodium reabsorbed Signup and view all the answers

What is the effect of increased aldosterone on the principal cells?

Increased sodium ion reabsorption and potassium ion secretion Signup and view all the answers

What is the effect of decreased sodium ions or increased potassium ions in the blood on aldosterone levels?

An increase in aldosterone levels Signup and view all the answers

What is the function of sodium/potassium ATPase pumps in the basolateral membrane?

Sodium ion reabsorption and potassium ion secretion Signup and view all the answers

What is the effect of antidiuretic hormone (ADH) on the principal cells?

Stimulation of water reabsorption Signup and view all the answers

Why does water not follow the solute in the principal cells unless stimulated by ADH?

The luminal membrane is impermeable to water unless stimulated by ADH Signup and view all the answers

What is the primary function of principal cells in the late distal convoluted tubule and collecting ducts?

Regulation of water and sodium reabsorption Signup and view all the answers