Final answer:
The adrenal gland is the gland located at the top of the kidney, responsible for secreting hormones important in stress responses and regulating various bodily functions.
Step-by-step explanation:
The gland located at the top of the kidney is the adrenal gland. Each kidney has one adrenal gland sitting on its top, and these glands play a pivotal role in the body's response to stress. The adrenal glands are made up of two main parts: the outer adrenal cortex and the inner adrenal medulla. The adrenal cortex produces corticosteroids, which include hormones like cortisol that help regulate metabolism, immune response, and stress reactions. Meanwhile, the adrenal medulla produces catecholamines such as epinephrine (adrenaline) and norepinephrine (noradrenaline), which are crucial for the fight-or-flight response. These hormones together facilitate the regulation of blood pressure, water homeostasis, and electrolyte levels, and are important for the body's ability to cope with stress.