Nervous System Overview

Introduction

• The nervous system, primarily the brain, is unique for enabling human consciousness and intelligence.
• Main function: Coordinate all body activities, respond/adapt to internal and external changes.
• Divided into two parts: Central Nervous System (CNS) and Peripheral Nervous System (PNS).

Central Nervous System (CNS)

• Composed of the brain and spinal cord.

Brain

• Located within the cranium.
• Six main sections:
  1. Cerebrum
     • Largest section, divided into right and left hemispheres.
     • Further divided into four lobes:
       • Frontal Lobe: Responsible for reasoning and thought.
       • Parietal Lobe: Integrates sensory information.
       • Temporal Lobe: Processes auditory information.
       • Occipital Lobe: Processes visual information.
  2. Cerebellum
     • Located at the back of the head, above the neck.
     • Responsible for muscle coordination, balance, posture, muscle tone.
  3. Diencephalon
     • Contains the thalamus and hypothalamus.
     • Thalamus: Relay station for sensory impulses to the cerebrum.
     • Hypothalamus: Regulates autonomic functions (temperature, appetite, sleep), emotional responses.
  4. Midbrain
     • Located below the cerebrum, responsible for eye and auditory reflexes.
  5. Pons
     • Located below the midbrain, responsible for reflex actions like chewing, tasting.
  6. Medulla Oblongata
     • Connects with the spinal cord, regulates heart and blood vessel function, digestion, respiration.

Spinal Cord

• Connects the brain to peripheral body nerves.
• Four regions: Cervical, thoracic, lumbar, and spinal nerves.
• Afferent nerves: Carry info from body to brain.
• Efferent nerves: Carry info from brain to body.

Peripheral Nervous System (PNS)

• Regulates functions outside the CNS.
• Subdivided into:
  1. Somatic Nervous System
     • Carries motor and sensory info to/from CNS.
     • Involves voluntary muscle movements and sensory processing.
     • Uses afferent (sensory) and efferent (motor) neurons for communication.
  2. Autonomic Nervous System
     • Divided into:
       • Sympathetic Nervous System: Initiates fight-or-flight response.
       • Parasympathetic Nervous System: Balances body's systems post-threat.

Recap

• Nervous system coordinates body activities, adapts to changes.
• Major components: CNS (brain and spinal cord) and PNS.
• CNS: Brain (six sections) and spinal cord (four regions, nerve connections).
• PNS: Somatic and autonomic systems.
• Nervous system complexity is vast - this lecture covers basics.

Further Learning

• For more information, visit cteskills.com.