38 Questions
What is the aid in water reabsorption through the plasma membrane?
Aquaporins
What is the result of increasing interstitial osmolarity?
Water diffusion out of the tubular lumen
What is the primary function of the proximal convoluted tubule?
Reabsorption of valued substances
What is the primary mechanism of water reabsorption in the nephron?
Diffusion through aquaporins
What is the result of sodium ion transport in the nephron?
Increased reabsorption of substances
What is the purpose of the basalateral membrane in the proximal convoluted tubule?
Enables active transport of sodium ions
What is the significance of sodium ion reabsorption in the nephron?
Enables reabsorption of valued substances
What is the role of tight junctions in the nephron?
Permits diffusion of water and solutes
What is the main function of the high osmolarity of the medullary interstitium?
To pull water out of the filtrate
What is unique about the cells in the thin descending loop of Henle?
They lack transport proteins
What happens to the filtrate as it passes down the thin descending loop of Henle?
It becomes more concentrated
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
What is the function of the secondary active transport molecule in the ascending loop of Henle and early DCT?
To cotransport potassium and chloride
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
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
What is the result of the reabsorption of water in the thin descending loop of Henle?
The filtrate becomes more concentrated
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
What happens to the filtrate as it moves down the descending limb?
It becomes more concentrated as water diffuses into the tubule
What is the concentration of solutes in the filtrate at the bottom of the loop?
Approximately four times greater than normal body fluid
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
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
What is the result of the sodium/potassium ATPase ion pump yielding its energy?
ATP is converted to ADP and an inorganic phosphate ion
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
What is the purpose of the osmotic gradient created by the ascending limb?
To maintain the osmotic gradient necessary for the countercurrent multiplier mechanism
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
What is the role of the potassium ion channel in the basolateral membrane?
To prevent potassium ion depletion in the blood or excess accumulation
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
What type of transport does the glucose carrier molecule use to transport glucose across the basolateral membrane?
Facilitated diffusion
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
What type of transport is responsible for carrying out the sodium/potassium ATPase ion pump's function?
Active transport
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
What is the role of aldosterone in the late distal convoluted tubule and collecting ducts?
Precise regulation of the final amount of sodium reabsorbed
What is the effect of increased aldosterone on the principal cells?
Increased sodium ion reabsorption and potassium ion secretion
What is the effect of decreased sodium ions or increased potassium ions in the blood on aldosterone levels?
An increase in aldosterone levels
What is the function of sodium/potassium ATPase pumps in the basolateral membrane?
Sodium ion reabsorption and potassium ion secretion
What is the effect of antidiuretic hormone (ADH) on the principal cells?
Stimulation of water reabsorption
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
What is the primary function of principal cells in the late distal convoluted tubule and collecting ducts?
Regulation of water and sodium reabsorption
This quiz covers the process of water reabsorption in cells, including the role of aquaporins in facilitating water transport across cell membranes.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
