Caffeine increases activity not only in the brain but also in the branch of the nervous system serving the body. This branch is called the _____ nervous system.

Caffeine is a substance widely used in the workplace or at home for stimulation the peripheral and central nervous system. It enables people to stay in alert, as caffeine blocks some neurotransmitters like adenosine, the brain will remain in an active state of mind, although in the long term if taking several cups of tea other negative symptoms can occur.

Taking coffe decreases the blood flow in the brain yet increasing the metabolism in the brain making noradrenaline neurons and release of dopamine more likely. This will help have a state of alert, initially and can be sustained for some hours.

People may experience fast heart rate, with the recurring need for urine, as well as feelings of anxiety or uncontrolled nervousness.

It is widely unencouraged to take coffe only early in the morning in the late afternoon or at night since it will cause insomnia.