Adrenaliinia

Adrenaliinia, or adrenaline, also known as epinephrine, is a hormone and neurotransmitter in humans. It is produced by the adrenal medulla and released into the bloodstream in response to stress as part of the sympathetic nervous system and the fight-or-flight response. It prepares the body for rapid action by increasing heart rate, cardiac output, and blood glucose, while redirecting blood toward muscles and vital organs.

Biochemically, adrenaline acts on adrenergic receptors, including alpha and beta subtypes. Activation of beta-1 receptors increases heart rate and contractility; beta-2 receptors produce bronchodilation and skeletal-muscle vasodilation; alpha-1 receptors cause vasoconstriction in skin and gut. Metabolic effects include stimulation of glycogenolysis and gluconeogenesis in the liver and lipolysis in adipose tissue.

Physiological effects depend on dose and tissue; the overall outcome is enhanced energy supply, improved airway flow, and elevated alertness. In medicine, adrenaline is used in emergency treatment of anaphylaxis and cardiac arrest, often by intramuscular injection or intravenous infusion. It is also used as a local vasoconstrictor in some anesthetics to prolong effect and reduce bleeding, and as a bronchodilator in severe asthma.

Side effects can include anxiety, tremor, palpitations, hypertension, and, in susceptible individuals, arrhythmias. It can interact with certain drugs, such as beta-blockers and monoamine oxidase inhibitors, and requires cautious use in patients with cardiovascular disease.