Your kidney seizes which hurts so much that you cry and you must go to a Doctor right away
When this tube is blocked, urine backs up into the kidney
Of course. The kidneys are connected to ureter tubes; waste is filtered through the kidneys and emerges as (relatively!) clean urine.
The kidney attached to that ureter would not function properly. uremia could develop.
The ureter leads to the bladder where urine is stored until it is voided.