2008 bio ce mc 46 water conten

can someone explain why B is not the answe in 2008 bio ce mc?
→請將全題列出。我也許可回答。

why isnt most water is reabsorbed to renal vein and the water content is higher than
that in the ureter ?
→腎靜脈接收了大部份原來就在腎動脈的水。輸尿管不應有吸水功能。

2013-02-26 11:31:58 補充：
答案是D無誤!因為腎靜脈和腎動脈中的血都是具有血漿蛋白和血球的血液，而輸尿管中的尿液已不含血漿蛋白和血球了。再怎麼樣調節血液的水含量也是低於尿液的水含量。
而尿素在腎元中是被濃縮的，自然再怎麼樣也是尿液要大於血液。

2013-02-27 10:13:11 補充：
but what does 水含量 means ?→ water potential 。

I am confused because i think as nearly all the water is reabsorbed into blood vessel, why its water content will be lower ?
→自腎元過濾出的物質一定是小分子(如水)。因此輸尿管中的水含量自然高。

2013-03-04 10:27:49 補充：
hen why b is the incorrect anser
→抱歉!上面的 renal vein and the "water content" is higher than
that in the ureter ?是指水勢。(等於水濃度)

2013-03-04 10:30:01 補充：
if so, the water potential of urine will be very low ?
→同上，水勢是上升的。
and lower than that in renal vein ?'
→不是!水勢(水的濃度)是上升的。

2013-03-04 10:46:19 補充：
if so, the water potential of urine will be very low ?
→同上，水勢(水濃度)是上升的。
and lower than that in renal vein ?'
→不是!尿的水含量(水勢)是較血液高。

2013-03-05 13:19:11 補充：
whyisnt most water is reabsorbed to renal vein and the water content is higherthanthatin the ureter ?→腎靜脈接收了大部份原來就在腎動脈的水。輸尿管不應有吸水功能。答案是D無誤!因為腎靜脈和腎動脈中的血都是具有血漿蛋白和血球的血液，而輸尿管中的尿液已不含血漿蛋白和血球了。再怎麼樣調節血液的水含量也是低於尿液的水含量。而尿素在腎元中是被濃縮的，自然再怎麼樣也是尿液要大於血液。butwhat does 水含量 means ?→ waterpotential 。 Iam confused because i think as nearly all the water is reabsorbed into bloodvessel, why its water content will be lower ?→自腎元過濾出的物質一定是小分子(如水)。因此輸尿管中的水含量自然高。henwhy b is the incorrect anser→抱歉!上面的 renal vein and the "watercontent" is higher than that in the ureter ?是指水勢。(等於水濃度)ifso, the water potential of urine will be very low ? →同上，水勢是上升的。andlower than that in renal vein ?'→不是!水勢(水的濃度)是上升的。ifso, the water potential of urine will be very low ? →同上，水勢(水濃度)是上升的。andlower than that in renal vein ?'→不是!尿的水含量(水勢)是較血液高。 如有疑議請補充!我可以針對您的問題再解說。