Divisions of the Nervous System

Major Divisions

• Central Nervous System (CNS)

  • Composed of the brain and spinal cord.

• Peripheral Nervous System (PNS)

  • Consists of nerves running throughout the body.

Subdivisions of the Peripheral Nervous System

Somatic Nervous System

• Function:
  • Carries sensory signals from the body to the CNS.
  • Transmits motor signals from the CNS to skeletal muscles.
• Association:
  • Linked to voluntary movement, e.g., clicking a video involves the somatic nervous system.

Autonomic Nervous System

• Function:
  • Regulates the body's internal environment.
  • Carries signals between internal organs and the CNS.
• Also Known As:
  • Involuntary nervous system.
• Regulates:
  • Digestion, heartbeat, and other functions outside conscious control.

Subdivisions of the Autonomic Nervous System

Sympathetic Nervous System

• Role:
  • Stimulates and mobilizes energy resources.
  • Involved in the 'fight or flight' response.
• Effects:
  • Increases heart rate and blood pressure.
  • Stimulates sweat glands.

Parasympathetic Nervous System

• Role:
  • Conserves energy.
  • Involved in 'rest and digest' responses.
• Effects:
  • Stimulates digestion and salivation.
  • Slows heart rate.

Summary

• The nervous system is divided into central and peripheral systems, with the peripheral system further divided into somatic (voluntary control) and autonomic (involuntary control) systems.
• The autonomic system is further split into sympathetic and parasympathetic systems, managing energy mobilization and conservation respectively.