Anatomy & Physiology: Nervous System Overview

Anatomy & Physiology Overview

  • Biology-50A:
    • Skeletal System
    • Muscle System
    • Central Nervous System (CNS)
  • Biology-50B:
    • Peripheral Nervous System (PNS)
    • Autonomic Nervous System
    • Endocrine System
    • Cardiovascular System
    • Respiratory System
    • Digestive System
    • Excretory System
    • Reproductive System

Nervous System Components

  • CNS:
    • Brain
    • Spinal Cord
  • PNS:
    • Cranial Nerves
    • Spinal Nerves
    • Ganglia

Neurons

  • Main Types:
    • Neurons (active signaling)
    • Glial Cells (supporting)
  • Function:
    • Dendrites: Receive signals
    • Axon: Transmits signals
    • Action Potential: Triggered at Axon Hillock if sufficient Na+ influx occurs

Information Processing Stages

  1. Sensory Input: Detect stimuli and transmit signals to CNS
  2. Integration: Interneurons process signals for response selection
  3. Motor Response: Signal relayed to motor neurons to execute response

Nervous Systems Interaction

  • CNS: Integrates and processes signals, deciding actions to take
  • PNS: Transmits information to/from CNS
    • Afferent Neurons: Carry sensory information to CNS
    • Efferent Neurons: Carry motor information away from CNS

Neuron Classes in PNS

  • Afferent Neurons: Sensory, transmit signals TO CNS
  • Efferent Neurons: Motor, transmit responses AWAY from CNS

Functional Hierarchy of Nervous System

  • Motor Division:
    • Somatic System (voluntary)
    • Autonomic System (involuntary)
    • Parasympathetic Division
    • Sympathetic Division

Conclusion

  • The nervous system acts as the master control system, coordinating signals for voluntary and involuntary actions through a hierarchical structure of interconnected components.