Final answer:
The hypothalamus is the part of the brain that controls the pituitary gland, playing a key role in regulating homeostasis and various other bodily functions.
Step-by-step explanation:
The part of the brain that controls the pituitary gland is the hypothalamus. The hypothalamus is located in the diencephalon of the brain and plays a crucial role in homeostasis by regulating the autonomic nervous system and the endocrine system. It synthesizes hormones and transports them to the posterior pituitary gland, and also secretes regulatory hormones that control the endocrine cells in the anterior pituitary gland. In addition, the hypothalamus is involved in various functions, such as body temperature regulation, circadian rhythms, and it forms part of the limbic system, which is associated with emotion and memory.