Fundamentals of Neuroscience/Classification of the Nervous System

Resource type: this resource is a lesson.

Subject Classification: this is a neuroscience resource.

Goals

• To learn about how the nervous system is divided
• To learn the functions and responsibilites of each division
• To learn how the sections of the nervous system interact with each other

Primary Divisions

• The central nervous system (CNS) consists of the brain and spinal cord and has the greatest diversity of functions, ranging from thought to perception
• The peripheral nervous system (PNS) consists of all the neural cells located outside the brain and spinal cord, and primarily sends sensory signals to the CNS and receives motor signals from the CNS. The PNS can be divided itself into two groups:
  • The somatic nervous system controls the movement of voluntary skeletal muscles
  • The autonomic nervous system regulates more involuntary functions, such as cardiac muscles

Sympathetic vs. Parasympathetic

• The autonomic nervous system itself can be divided into the sympathetic and parasympathetic nervous systems:
  • The parasympathetic nervous system is responsible for rest and digest functions including:
    • Lowering breathing rate
    • Slowing down heart
    • Encouraging the secretion of stomach enzymes
  • The sympathetic nervous system is responsible for fight or flight functions, including
    • Raising breathing rate
    • Speeding up heart
    • Stopping the secretion of stomach enzymes
• These two divisions work antagonistically, and must be balanced to preserve homeostasis

Exercises

• Identify the portion of the Nervous System most involved in the following functions:
  1. Feeling that ice cream is cold
  2. Contemplating why ice cream feels cold
  3. Kick generated from a doctor hitting below the knee
  4. Kick generated by a professional kickboxer in a match
  5. Eyes dilating from an approaching bear