Write the function of adrenaline hormone.

Adrenaline, also known as epinephrine, is a hormone secreted by the adrenal glands (located above the kidneys) that prepares the body for "fight or flight" responses during stressful or emergency situations. When you encounter danger, stress, or excitement, adrenaline is rapidly released into the bloodstream, triggering immediate physiological changes that enhance your ability to respond quickly and effectively.

The primary functions of adrenaline include increasing heart rate and blood pressure to pump more blood to muscles, dilating air passages to improve oxygen intake, releasing stored glucose for instant energy, redirecting blood flow away from non-essential systems (like digestion) toward muscles and brain, and sharpening mental alertness and reaction time. It also causes pupils to dilate for better vision and triggers the release of clotting factors in case of injury. These changes happen within seconds, which is why you might feel your heart pounding and become hyper-alert when startled or frightened. Medically, synthetic adrenaline is used to treat severe allergic reactions (anaphylaxis), cardiac arrest, and asthma attacks. While adrenaline responses are life-saving in true emergencies, chronic stress leading to frequent adrenaline release can contribute to health problems like anxiety, high blood pressure, and cardiovascular strain.