City and Guilds Animal Management Level 3 Biological Systems Practice Test

The primary function of adrenaline, also known as epinephrine, released by the adrenal glands is to prepare the body for action. This hormone is a crucial component of the body's "fight or flight" response, which is activated in stressful situations. When adrenaline is released into the bloodstream, it triggers a range of physiological changes that enhance the body's ability to respond to perceived threats.

These changes include increasing heart rate, raising blood pressure, and boosting energy supply by facilitating the breakdown of glycogen into glucose for immediate energy. Additionally, adrenaline dilates air passages in the lungs and opens up blood vessels to essential muscles, allowing for improved oxygen delivery and physical performance.

Therefore, this preparation for action is vital for survival in emergency situations, making the role of adrenaline central to how the body responds to stress and danger.