Unconsciousness will occur after 8-10 seconds after loss of blood supply to the brain. The brain is responsible for everything that we do, feel and think. Those who study this are called phychobiologists. They study brain anatomy and the rest of the nervous system to determine how they affect our behavior. Neurons are individual nerve cells responsible for transmitting information throughout the body.
All behavior is a result of neuronal activity.
The PNS includes all nerves going to and from the brain and spinal cord. Incoming sensory information is called afferent. Outgoing motor information is called efferent. SNS responds to external stimuli and regulates voluntary actions. These work in opposition to each other to regulate organs such as the heart, intestines, and lungs.