What is the role of the adrenal glands in the endocrine system?

The adrenal glands play a vital role in the endocrine system by regulating metabolism and the body's response to stress. They produce hormones such as cortisol, which is essential for glucose metabolism and helps the body respond to stress by increasing energy availability. Additionally, the adrenal glands secrete adrenaline (epinephrine), which is crucial during "fight or flight" situations, enhancing the body's ability to respond to stress through increased heart rate, improved blood flow to muscles, and heightened alertness. This dual role of managing metabolic processes while responding to stressors underscores the importance of the adrenal glands in maintaining overall homeostasis within the body.

While other functions mentioned in the choices are related to endocrine regulation, they are not primarily regulated by the adrenal glands. Blood glucose levels are primarily controlled by insulin and glucagon from the pancreas. Digestion is largely supported by hormones from the gastrointestinal system. Nitrogen balance is influenced mainly by the kidneys and liver in relation to protein metabolism.