ALPHA AND BETA RECEPTOR PROPERTIES Alpha-1 receptors Location: Vascular smooth muscle Effect: Vasoconstriction Clinical significance: Increases blood pressure by narrowing blood vessels. Epinephrine and norepinephrine stimulate these receptors. Alpha-2 receptors Location: Presynaptic nerve terminals and CNS Effect: Inhibits norepinephrine release Clinical significance: Helps regulate sympathetic nervous system activity and decreases sympathetic outflow. Beta-1 receptors Location: Heart Effects: - Increased heart rate (chronotropic effect) - Increased contractility (inotropic effect) - Increased conduction through AV node Clinical significance: Stimulation increases cardiac output. Beta-2 receptors Location: Lungs, vascular smooth muscle, uterus Effects: - Bronchodilation - Vasodilation - Relaxation of uterine smooth muscle Clinical significance: Albuterol works by stimulating beta-2 receptors to open the airways. PHYSIOLOGY OF CELLULAR FUNCTION Cells generate energy primarily through metabolism of glucose in the mitochondria. Key cellular functions include: Energy production ATP is produced through aerobic metabolism using oxygen and glucose. Cell membrane transport The membrane regulates movement of substances in and out of the cell. Active transport Requires energy to move substances against a concentration gradient. Passive transport Diffusion or osmosis moves substances along a concentration gradient. Cellular injury occurs when oxygen delivery is insufficient, leading to anaerobic metabolism and lactic acid buildup. HELICOPTER USE ON SCENE Air medical transport may be used when: - The patient has severe trauma or critical illness - Ground transport time is excessive - The patient requires rapid access to specialty care (trauma center, stroke center, burn center) - Terrain or traffic prevents timely ground transport Important considerations: - Scene safety - Landing zone size and hazards - Coordination with incident command - Weather conditions