Search results
Results From The WOW.Com Content Network
Diagram outlining movement of ions in nephron, with the collecting ducts on the right. The collecting duct system is the final component of the kidney to influence the body's electrolyte and fluid balance. In humans, the system accounts for 4–5% of the kidney's reabsorption of sodium and 5% of the kidney's reabsorption of water. At times of ...
The collecting duct system begins in the renal cortex and extends deep into the medulla. As the urine travels down the collecting duct system, it passes by the medullary interstitium which has a high sodium concentration as a result of the loop of Henle's countercurrent multiplier system. [1]: 67
The 300 mOsm/L fluid from the loop loses water to the higher concentration outside the loop and increases in tonicity until it reaches its maximum at the bottom of the loop. This area represents the highest concentration in the nephron, but the collecting duct can reach this same tonicity with maximum ADH [clarification needed] effect. [3]
H + secretion is carried out mainly through Na + /H + exchangers in the tubules of the nephron. [150] The collecting ducts are involved in the energy-dependent secretion of H +. [151] When H + ions enter the urine, they can combine with filtered HCO 3-to form carbonic acid H 2 CO 3, which is being converted into CO 2 and H 2 O (water) by the ...
The initial filtering portion of a nephron is the renal corpuscle, which is located in the cortex. This is followed by a renal tubule that passes from the cortex deep into the medullary pyramids. Part of the renal cortex, a medullary ray is a collection of renal tubules that drain into a single collecting duct. [citation needed]
This allows urea to leave the collecting duct into the medulla, creating a hyperosmotic solution that "attracts" water. Urea can then re-enter the nephron and be excreted or recycled again depending on whether ADH is still present or not.
At this location, in the wall of the last portion of distal straight tubule, there is a modified region of tubular epithelium called the macula densa.(Fig. 5 in Kumaran and Hanukoglu 2020) [5] Cells in the macula densa respond to changes in the sodium chloride levels in the distal tubule of the nephron via the tubuloglomerular feedback (TGF) loop.
The composition of tubular fluid changes throughout the nephron, from the proximal tubule to the collecting duct and then as it exits the body, from the ureter. Concentration (m M ) of substances in different segments of nephron and collecting duct system