UWorld Endocrine Practice Test

The hormone primarily involved in the body's fight-or-flight response is adrenaline, also known as epinephrine. This response is mediated by the sympathetic nervous system, which is activated in instances of stress or perceived danger. Adrenaline is released from the adrenal medulla, a part of the adrenal glands, and plays a crucial role in preparing the body to face a challenging situation.

When adrenaline is released into the bloodstream, it triggers various physiological changes. These include increased heart rate, elevated blood pressure, dilation of air passages in the lungs, and heightened blood flow to muscles, all of which enhance the body's ability to react swiftly. Additionally, by triggering the liver to release glucose into the bloodstream, adrenaline ensures that energy is readily available for immediate use, further supporting the body's preparedness to either confront or escape from a threat.

Other hormones, such as cortisol, also play a role in stress responses but do so in a different manner, typically contributing to longer-term stress management and metabolic regulation rather than the immediate effects associated with fight-or-flight. Norepinephrine, while also involved in the fight-or-flight response, primarily acts as a neurotransmitter and works alongside adrenaline but is not as directly associated with the acute physical responses. Insulin, on the other hand