阅读短文，选择填空。

    My grandfather is fifty-five years old. He's a taxi driver. He loves his job very much. It is Sunday. Today is his birthday. My father, my mother and I are in his home. My uncle also comes here. He's a tall man. He's a worker. He comes to see my grandfather every Sunday. My grandfather has a good friend. His name is Jim. He's from England. He's a nice cook. He comes to see him, too. My grandfather is very happy today.

下表中的数据是取自某正常人原尿和尿液的样品，如图是肾单位结构模式图，请根据表格数据和示意图回答下列问题．

（1）根据表中的数据分析，原尿是____ （填“样品A”或“样品B”），存在于图中____ 肾小囊腔中．

（2）尿液是原尿经图2中肾小管的重吸收后形成的，重吸收的物质包括全部的____ ，大部分的水和部分____ ．图中456合称为____ 

（3）若5肾小球有炎症，尿液中会出现血细胞和大分子____ ；若尿液中出现葡萄糖，则可能是图中6____ 出现病变．

（4）代谢废物中的尿素除了以尿液形式排除外，还可以通过皮肤以____ 形式排出．