Electricity and the Body

Muscle cells can Generate potential differences

• Between the inside of a cell and the outside there is a poetential differnce
• These can be measured with needle electrodes. 
• Resting potential of a muscle cell is -70V

An electromyography machine detects electrical signals in the muscle

• used for identifying problems
• used as a training tool (help people walk again)

EMGs meausre the Action Potentials of the Heart 

When the heart beats an action potential passes through the artia, making them contract. A secound later, an action potential passes through the ventricles, making them contract to. 

P) Arium contracts      QRS) Ventrical contracts & Arium rests       T) Ventrical rests