Page 1 of 2: physio mock test 50

doctorgirl78 · Credits: 5306 My Scrapbook

10) A reduction in dietary intake of K+ would be expected to alter K+ transport in which segment of the nephron ?

One answer only.

a) PCT
b) Descending limb of Henle
c) Proximal straight tubule
d) Collecting duct
e) Thick ascending limb of Henle

help me with this Q please................

doctorgirl78 · Credits: 5306 My Scrapbook

still wondering

jayanta · Credits: 34192 My Scrapbook My Reading List 45 Books

IT IS PROXIMAL CONVOLUTED TUBULE.

Anatomicus · Credits: 493 My Scrapbook My Reading List 8 Books

I thought So!!!!!!!!!!

ujwals · Credits: 4860 My Scrapbook

#4

drsainish · Credits: 11255 My Scrapbook

e) Thick ascending limb of Henle

ujwals · Credits: 4860 My Scrapbook

Much of the filtered K+ is removed from the tubular fluid by active reabsorption in the proximal tubules , and K+ is then secreted into the fluid by the distal tubular cells. The rate of K+ secretion is proportionate to the rate of flow of the tubular fluid through the distal portions of the nephron, because with rapid flow there is less opportunity for the tubular K+ concentration to rise to a value that stops further secretion. In the absence of complicating factors, the amount secreted is approximately equal to the K+ intake, and K+ balance is maintained. In the distal tubules, Na+ is generally reabsorbed and K+ is secreted. There is no rigid one-for-one exchange, and much of the movement of K+ is passive. However, there is electrical coupling in the sense that intracellular migration of Na+ tends to lower the potential difference across the tubular cell, and this favors movement of K+ into the tubular lumen. Since Na+ is also reabsorbed in association with H+ secretion, there is competition for the Na+ in the tubular fluid. K+ excretion is decreased when the amount of Na+ reaching the distal tubule is small, and it is also decreased when H+ secretion is increased. When total body K+ is high, H+ secretion is inhibited, apparently because of intracellular alkalosis; K+ secretion and excretion are therefore facilitated. Conversely, the cells are acidic in K+ depletion, and K+ secretion declines. Apparently the K+ secretory mechanism is capable of "adaptation," because the amount of K+ excreted gradually increases when a constant large dose of a potassium salt is administered for a prolonged period.

THEROCK · Credits: 1456 My Scrapbook

i agree with ujwals

jayanta · Credits: 34192 My Scrapbook My Reading List 45 Books

OOOOOOOOPPPPPPSSSSSS.
UJWALS.
IT IS GREAT.
REGARDS.
HAPPY INDEPENDENCE DAY.

vishal_goyal1997 · Credits: 217 My Scrapbook

ch of the filtered K+ is removed from the tubular fluid by active reabsorption in the proximal tubules , and K+ is then secreted into the fluid by the distal tubular cells. The rate of K+ secretion is proportionate to the rate of flow of the tubular fluid through the distal portions of the nephron, because with rapid flow there is less opportunity for the tubular K+ concentration to rise to a value that stops further secretion. In the absence of complicating factors, the amount secreted is approximately equal to the K+ intake, and K+ balance is maintained. In the distal tubules, Na+ is generally reabsorbed and K+ is secreted. There is no rigid one-for-one exchange, and much of the movement of K+ is passive. However, there is electrical coupling in the sense that intracellular migration of Na+ tends to lower the potential difference across the tubular cell, and this favors movement of K+ into the tubular lumen. Since Na+ is also reabsorbed in association with H+ secretion, there is competition for the Na+ in the tubular fluid. K+ excretion is decreased when the amount of Na+ reaching the distal tubule is small, and it is also decreased when H+ secretion is increased. When total body K+ is high, H+ secretion is inhibited, apparently because of intracellular alkalosis; K+ secretion and excretion are therefore facilitated. Conversely, the cells are acidic in K+ depletion, and K+ secretion declines. Apparently the K+ secretory mechanism is capable of "adaptation," because the amount of K+ excreted gradually increases when a constant large dose of a potassium salt is administered for a prolonged period.
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