What Is an Automated External Defibrillator? An automated external defibrillator (AED) is a portable device that checks the heart rhythm and can send an electric shock to the heart to try to restore a normal rhythm. AEDs are used to treat sudden cardiac arrest (SCA). SCA is a condition in which the heart suddenly and unexpectedly stops beating.
curl. 1  to form into coils or ringlets, as the hair. 2  to form into a spiral or curved shape; coil. 3  to adorn with, or as with, curls or ringlets. 4  to grow in or form curls or ringlets, as the hair. 5  to become curved or undulated. 6  to coil. 7  to play at the game of curling.
The agonist is not always the muscle that is shortening (contracting concentrically). In a bicep curl the bicep is the agonist on the way up when it contracts concentrically, and on the way down when it contracts eccentrically. This is because it is the prime mover in both cases. 2.