Abhishek on Instagram: "The Dopamine Trap ⚠️ The Entry: When you inhale, nicotine enters the bloodstream and reaches the brain in about 7 to 10 seconds. 2. The Lock & Key: It attaches to specific binding sites called acetylcholine receptors (specifically the alpha-4 beta-2 nicotinic receptors). 3. The Release: This connection triggers a rapid release of Dopamine—the “feel-good” neurotransmitter associated with pleasure and reward. 4. The Trap: This floods the brain’s reward pathways, tricking th

Rosalindfrankiln on Instagram: "Muscle contraction (short explanation) 🔥 Muscle contraction occurs by the sliding filament mechanism. A nerve impulse releases acetylcholine, generating an action potential in the muscle fiber. Calcium ions (Ca²⁺) are released from the sarcoplasmic reticulum. Ca²⁺ binds to troponin, causing tropomyosin to move and expose binding sites on actin. Myosin heads attach to actin, forming cross-bridges. Using ATP, myosin pulls actin inward, shortening the sarcomere. Rep