In your own words, explain why all endocrine glands have blood vessels coming from them.

Endocrine glands are a part of the body's control system that produce and secrete hormones directly into the bloodstream. These hormones are chemical messengers that travel through the blood to reach target cells or organs, where they trigger specific responses.

The presence of blood vessels in endocrine glands is crucial for this process. Here's why:

1. Production: Endocrine glands produce hormones. These hormones are complex chemical substances that regulate various body functions. They need nutrients and oxygen to do this, which are supplied by the blood vessels.

2. Secretion: Once the hormones are produced, they need to be transported to their target cells or organs. Unlike exocrine glands, which have ducts to carry their secretions to specific locations, endocrine glands are ductless. They rely on blood vessels to carry their hormones throughout the body.

3. Distribution: The blood vessels not only carry the hormones away from the gland, but they also distribute them throughout the body. The hormones travel in the bloodstream until they reach their target cells or organs.

4. Regulation: The blood vessels also play a role in regulating hormone levels. If the level of a certain hormone in the blood is too high or too low, it can signal the gland to adjust its production.

So, in summary, endocrine glands have blood vessels coming from them because these vessels supply the glands with nutrients, carry away the hormones they produce, distribute these hormones throughout the body, and help regulate hormone levels.