In human beings urea is formed by.

Urea is an organic nitrogen compound which is a waste product from the breakdown of proteins through nitrogen metabolism. It is excreted in dissolved form with the urine. It is used as a highly concentrated nitrogen fertilizer, and for making skin cosmetics.

Urea is found naturally in the urine of all mammals. When the body breaks down amino acids, its nitrogen is converted to the toxic substance ammonia, which in turn is converted to urea in the urea cycle. The amino acids are derived from degraded proteins.

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d