Which of the following hormone is also known as flight or fight hormone?

Adrenaline

The correct answer is Option 1. Adrenaline

Let us explore adrenaline, also known as epinephrine, in detail, particularly in the context of its role as the "fight or flight" hormone.

Adrenaline is a catecholamine hormone produced by the adrenal glands, specifically in the adrenal medulla. It plays a crucial role in the body’s acute stress response.

Synthesis and Release

Synthesis: Adrenaline is synthesized from the amino acid tyrosine through a series of steps involving its conversion to dopamine, norepinephrine (noradrenaline), and finally, adrenaline.

Release: During a stressful situation (physical or emotional), the sympathetic nervous system is activated. This triggers the adrenal glands to release adrenaline into the bloodstream.

"Fight or Flight" Response

The "fight or flight" response is the body's immediate reaction to a perceived threat. Adrenaline prepares the body to either confront or flee from danger. Here’s how it works:

Physiological Changes:

Increased Heart Rate: Adrenaline causes the heart to beat faster and stronger, increasing blood flow to muscles and vital organs.

Elevated Blood Pressure: Blood vessels constrict to raise blood pressure, ensuring that oxygen and nutrients reach tissues quickly.

Enhanced Respiratory Function: It dilates the bronchioles in the lungs, allowing for increased airflow and oxygen uptake.

Metabolic Effects:

Increased Blood Glucose Level: Adrenaline stimulates glycogenolysis (the breakdown of glycogen to glucose) in the liver, providing a quick energy source.

Fat Mobilization: It promotes lipolysis, the breakdown of fat stores for energy.

Neurological Effects:

Increased Alertness: Adrenaline enhances alertness and improves focus, allowing for quick decision-making and reactions.

Pain Perception: It can temporarily suppress pain sensations, enabling the body to respond to emergencies without being hindered by discomfort.

Digestive and Immune System:

Reduced Digestive Activity: Non-essential functions like digestion are slowed down, redirecting energy to muscles and the brain.

Immune Modulation: Adrenaline can influence immune responses, potentially suppressing inflammation in acute situations.

Clinical Importance

Medical Uses: Adrenaline is used in emergency medicine, particularly for treating severe allergic reactions (anaphylaxis) and cardiac arrest. It helps to rapidly reverse the symptoms of anaphylaxis and restore normal heart rhythms

Chronic Stress: While acute adrenaline release is beneficial, chronic stress can lead to continuous high levels of adrenaline, which may have negative health effects, including anxiety, high blood pressure, and increased risk of cardiovascular diseases.

Comparison with Other Hormones

Androgens: These are sex hormones (like testosterone) involved in male characteristics and reproduction, but they are not associated with the acute stress response.

Thyroxine: This thyroid hormone regulates metabolism but does not play a direct role in immediate stress responses.

Insulin: Produced by the pancreas, insulin regulates blood sugar levels but is not involved in the fight or flight response.

Conclusion

Adrenaline is a vital hormone in the body's response to stress, enabling quick physical reactions through various physiological and metabolic changes. Its role as the "fight or flight" hormone is crucial for survival, allowing organisms to respond effectively to threats. Understanding its mechanisms helps in recognizing its clinical applications and potential health impacts of chronic stress.