Question

Describe how the specific gravity of the urine changed after drinking water, and explain the physiological mechanisms responsible for this change.

Answer 1

Adult's urine generally has a specific gravity in the range of 1.000 to 1.030.

Increases in specific gravity of urine are said to be hypersthenuria. For example, increased the concentration of solute in the urine. While decreases in specific gravity of urine concentration result in hyposthenuria.
The concentration of solute levels may be slightly lower after drinking an unusually high amount of water, this occurs only because the urine has been diluted and concentration of solutes is less.
The lower protein level doesn't mean there are fewer solutes because it simply there is more water. Drinking an excessive amount of water is immediately apparent reason being urinalysis test which includes an indication for a specific gravity.
Specific gravity is referred to as the ratio which compares the density of urine compared to the density of water. If you drink a lot of water the specific gravity of urine is lower than normal.