Peripheral Nervous System

The Peripheral Nervous System (PNS) is composed of nerves and ganglia that are connected to the Brain but are technically outside of the brain itself and the Spinal Cord.

The main function of this system is to connect with the Central Nervous System (CNS).

The PNS is not protected by the bone of the spine or skull and there isn’t the protection of the blood-brain barrier.

The PNS allows the central nervous system to connect with the limbs and organs of the body.

The PNS is divided into two categories:

1.)  Somatic Nervous System

–  Has a function of body movement control and receiving stimulation for an external source.
–  Regulates activities that are under conscious control.

2.)  Autonomic Nervous System

The Autonomic Nervous System is divided into 3 divisions:

1.)  Sympathetic Division
2.)  Parasympathetic Division
3.)  Enteric Division

Sympathetic division – this is responsible for stimulation when danger and/or stress is present causing an increase in blood pressure, heart rate, excitement, and other physiological changes. This is an increase in adrenaline

Parasympathetic division – this is responsible for stimulation when no danger or stress is present but rather simplistic or relaxation is occurring. This causes a slowing heart rate, digestion, and other physiological changes. This is when no adrenaline is required.

Enteric division – this is responsible for the management of the digestion system from the oral cavity to the through the small intestines.