Notes on the Nervous System Lecture

Introduction

• The nervous system, often referred to as the brain, is unique due to its ability for self-awareness.
• This ability is known as Consciousness or Intelligence.

Primary Function of the Nervous System

• The primary purpose is to coordinate all body activities.
• Allows the body to respond and adapt to internal and external changes.

Parts of the Nervous System

Central Nervous System (CNS)

• Composed of:
  • Brain
  • Spinal Cord

Structure of the Brain

• Six main sections:
  1. Cerebrum
     • Largest section, divided into left and right 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 below the cerebrum, responsible for muscle coordination, balance, posture, and muscle tone.
  3. Diencephalon
     • Contains the thalamus and hypothalamus:
       • Thalamus: Relay station for sensory impulses.
       • Hypothalamus: Regulates autonomic functions (temperature, appetite, sleep, etc.) and emotions.
  4. Midbrain
     • Responsible for certain eye and auditory reflexes.
  5. Pons
     • Responsible for reflex actions (chewing, tasting, saliva production).
  6. Medulla Oblongata
     • Connects to the spinal cord and regulates heart function, digestion, respiration, and blood pressure.

Spinal Cord

• Link between the brain and the rest of the body.
• Divided into four regions:
  • Cervical
  • Thoracic
  • Lumbar
  • Afferent and Efferent spinal nerves
    • Afferent: Carries information from the body to the brain.
    • Efferent: Carries information from the brain to the body.

Peripheral Nervous System

• Comprises the nervous system outside the brain and spinal cord.
• Divided into two systems:
  • Somatic Nervous System:
    • Carries motor and sensory information to and from the CNS.
    • Involved in voluntary muscle movements and processing sensory information.
  • Autonomic Nervous System:
    • Controls involuntary functions and is divided into:
      • Sympathetic Nervous System: Responsible for fight or flight response.
      • Parasympathetic Nervous System: Counterbalances sympathetic responses, returning the body to normal after stress.

Recap

• Nervous system coordinates body activities and adapts to changes.
• Composed of CNS (brain and spinal cord) and Peripheral Nervous System.
• Peripheral system includes somatic and autonomic nervous systems.

• This lecture only covers the basics; the nervous system is complex and further exploration is encouraged.