Nervous system.txt

Concept that implies a state of "normalcy" in the body; it is reached when things are operating within normal biological limits.

• External environment
• Internal environment

• Central Nervous System
• Brain and spinal cord
• Does not include cranial and spinal nerves

Brain and spinal cord (CNS) involved in analysis of sensory information and problem solving

The CNS "decides" how to respond and does so through muscle contraction and glandular secretion

• Voluntary
• 12 pairs cranial nerves; 31 pairs spinal nerves
• Somatic nervous system (SNS)
• Autonomic nervous system (ANS)

carry impulses from receptors to CNS

carry impulses from CNS to effectors skeletal muscle only

Involuntary

carry impulses from visceral receptors to CNS

carry impulses from CNS to visceral effectors - smooth muscle, cardiac muscle and glands