The interaction function

Endocrine System
Presentation

Spinal nerves: they emerge from the spinal cord.

 THIBODEAU/PATTON.Estructura y función del cuerpo humano. Editorial Harcourt Brace.

THIBODEAU/PATTON.Estructura y función del cuerpo humano. Editorial Harcourt Brace.

The meninges (singular meninx from the Greek μῆνιγξ, "membrane"^[1]) is the system of membranes which envelopes the central nervous system. In mammals, the meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.
http://en.wikipedia.org/wiki/Meninges

There are two parts in the peripheral nervous system:

• The somatic NS: connects the sensory organs with the central nervous system and this in turn with the skeletal muscles. It controls the voluntary actions.
• The autonomic(or involuntary) NS: responsible for controlling involuntary body functions.

The parasympathetic system returns the body functions to normal after they have been altered by sympathetic stimulation. In times of danger, the sympathetic system prepares the body for violent activity. The parasympathetic system reverses these changes when the danger is over.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/PNS.html