Introduction to the Nervous System

Overview

• The nervous system is a complex communication network.
• It processes millions of bits of information every minute.

Functional Units

• Neurons: Primary cells that pick up and send information.
• Glia: Supporting cells with various types.

Information Processing

• Sensory neurons and organs collect information from the environment.
• Information types include:
  • Touch
  • Taste
  • Tickle
  • Temperature
  • Pain
  • Pressure
  • Sight
  • Sound
  • Stretch
  • Concentration

Information Flow

1. Afferent Signals (Sensory Signals)

   • Information is sent to the central nervous system (CNS), comprising the brain and spinal cord.
   • The CNS integrates or makes sense of the information.

2. Efferent Signals (Motor Signals)

   • CNS sends signals to muscles, glands, or organs to enact change.
   • Types of muscles affected:
     • Skeletal muscles (voluntary movement)
     • Smooth muscles (in hollow organs like digestive tract and urinary system)
     • Cardiac muscles (heart)
   • Signals can also affect glands, releasing hormones or chemicals, or organs like the pancreas.

Examples

• If the CNS senses something too hot, it may send a signal to move the arm away.