The hypothalamus maintains internal homeostasis and could be considered the master endocrine gland because.

a. It releases stimulating hormones that cause endocrine glands to produce their hormones. 

b. No hormone-releasing gland responds unless stimulated by the hypothalamus. 

c. It secretes releasing hormones that are an important part of the HPA. 

d. It regulates temperature control and arousal as well as hormone release.