Urea is formed in liver as the end product of protein metabolism and digestion. Urea is transported to the kidneys for excretion. A normal range for blood urea nitrogen is generally 8 to 24 mg/dl for adult males and 6 to 21 mg/dl for females.
Wyatt is a recurring character of the ABC Family series, The Fosters. He's Callie's first real friend in school, due to the fact that they are both outsiders. Eventually, he becomes her love interest often having an on-again/off-again relationship with her. He appears for the first time in Hostile Acts.
These two finally said they loved each other in last Monday's episode and Wyatt is clearly not in the relationship purely for physical reasons. He wants Callie to be happy, whether that is with a new biological father and sister or with The Fosters.