if endocrine glands r ductless........so all d hormones don't gt mixed up??

Endocrine glands secretes hormones into the blood on receiving certain signals from the brain. Blood in turn, transport these to the target tissues located away from the site of secretion. These hormone are specific in their function and do not cause any ill effect on the other organs of the body. They recognize their target cells or tissues due to the presence of specific receptor on them. So its not necessary that all the hormone are released in the blood stream at the same time and if present they do not get mixed due to their specific features.