Which glands are responsible for the "fight or flight" response?

The adrenal glands are primarily responsible for the "fight or flight" response, which is the body's acute stress response mechanism. When faced with a perceived threat, these glands rapidly release hormones like adrenaline (epinephrine) and norepinephrine into the bloodstream. This hormonal surge leads to physiological changes, such as increased heart rate, heightened alertness, and enhanced energy availability, all of which prepare the body to either confront or escape the threat.

The other glands listed do have important functions in the body but are not directly responsible for the immediate response to stressors. For example, the thyroid glands regulate metabolism, the pituitary gland controls various hormonal functions but acts more as a regulator of other glands rather than initiating the "fight or flight" response, and the pancreas is primarily involved in digestion and regulating blood sugar rather than acute stress responses.