The Nervous System

basic info:

• neurons are the fundamental components of the nervous system

• your brain consists of about 85 billion neurons

• these neurons are organized into different lobes, structures, and subdivisions

Nervous System

Peripheral                                                       Central

(rest of body)                                                                       (spinal cord and brain)

Autonomic Somatic

(self-regulated (body sensations and

control of internal organs) control of movements)

Sympathetic Parasympathetic

(arouses body) (calms the body)

Central Nervous System

• the brain + spinal cord

• process sensory information and send signals to body

Peripheral Nervous System

• nerves branching from spinal cord

• somatic and autonomic systems

Somatic Nervous System

• carries info from our sensory organs to our CNS

• allows us to understand what is happening around us

Autonomic Nervous System

• regulates psychological processes in the body 

• internal organs give CNS signs of what is happening

• contains sympathetic and parasympathetic

Sympathetic Division

• arouses body in emergencies by speeding heartbeat, raising blood pressure, and slowing digestion

• body then prepares to respond energetically to a threat or a challenge

Parasympathetic Division

• relaxes the body after an emergency passes

• then does the opposite of the sympathetic division