The endocrine gland that can function independently of the pituitary gland is Adrenal. The adrenal glands, situated atop each kidney, have two distinct regions: the adrenal cortex and the adrenal medulla. The adrenal cortex produces steroid hormones such as cortisol, aldosterone, and sex hormones (androgens). These hormones regulate metabolism, electrolyte balance, and reproductive functions, respectively. The secretion of adrenal cortex hormones is primarily regulated by factors such as stress, blood pressure, and electrolyte levels, rather than direct control from the pituitary gland.

While the pituitary gland does influence the adrenal glands through the secretion of adrenocorticotropic hormone (ACTH), which stimulates cortisol production, the adrenal glands can still function independently to some extent. In situations of stress, the adrenal glands can respond directly to stressors by releasing hormones without requiring signals from the pituitary gland, demonstrating their ability to function autonomously.