Needs of endocrine glands
Answers
There are 9 main endocrine glands in a human individual. They are known as endocrine because they are a class of glands that pour their secretions directly into the bloodstream, without any ducts to regulate the flow. The pancreas is an exception to this, as it has both endocrine (islets of Langerhans) as well as exocrine parts.
The endocrine system interacts with the neural system, through the hypothalamus, in the body when it comes to communication, and also when it comes to regulation of the endocrine gland function in itself. For example, being in dangerous situations triggers our fight/flight response, which happens due to an adrenaline surge.
Hence, endocrine glands are needed because they are crucial to processes like communication, growth and just about every major bodily function.