Overview of the Nervous System

Apr 16, 2025

Lecture Notes: The Language of Medicine - The Nervous System

Chapter 10: Overview

  • Focus on major organs and functions of the nervous system.
  • Understand nervous system combining forms with suffixes and prefixes.
  • Define pathological conditions affecting the nervous system.
  • Describe related lab tests, clinical procedures, and abbreviations.

Key Concepts

Nervous System Structure

  • 10 billion nerve cells facilitating voluntary and involuntary functions.
  • Neurons: Microscopic nerve cells forming macroscopic nerves.
  • Electrical Messages: Carried all over the body, activated by stimuli.

Divisions of the Nervous System

  • Central Nervous System (CNS): Brain and spinal cord.
  • Peripheral Nervous System (PNS): Cranial nerves, spinal nerves, plexuses, and peripheral nerves.

Functionality

  • Cranial Nerves: Carry impulses between the brain and head/neck.
  • Spinal Nerves: Carry impulses between the spinal cord and various body parts.
  • Autonomic Nervous System (ANS): Manages involuntary functions via sympathetic and parasympathetic systems.
    • Sympathetic: "Fight or flight" response.
    • Parasympathetic: "Rest and digest" response.

Neurons & Neurotransmitters

  • Neuron Structure: Dendrites, cell nucleus, axon, myelin sheath, terminal fibers.
  • Neurotransmitters: E.g., dopamine, acetylcholine, norepinephrine.
  • Pathways: Impulses transferred across synapses.

Glial Cells

  • Types: Astrocytes, microglial cells, oligodendroglia, ependymal cells.
  • Functions: Supportive, protective, and connective roles.

Brain Anatomy

  • Lobes: Frontal, temporal, parietal, occipital, Broca's, and Wernicke's areas.
  • Functions:
    • Frontal Lobe: Thought processes, behavior, personality.
    • Temporal Lobe: Hearing, understanding speech/language.
    • Parietal Lobe: Body sensations, visual/spatial perception.
    • Occipital Lobe: Vision.

Brain Components

  • Cerebrum: Largest part, managing speech, vision, smell, movement, etc.
  • Cerebellum: Coordinates voluntary movements, maintains balance.
  • Thalamus: Integrates and monitors sensory impulses.
  • Hypothalamus: Controls body temperature, appetite, emotions.
  • Brain Stem: Midbrain, pons, medulla oblongata managing autonomic functions.

Spinal Cord and Meninges

  • Spinal Cord: Pathway for impulses, extends from brain to L2 vertebra.
  • Meninges: Protective layers - dura mater, arachnoid membrane, pia mater.
  • Cerebrospinal Fluid (CSF): Cushions brain, circulates nutrients and waste.

Key Terms and Concepts

  • Blood-Brain Barrier: Keeps many substances out of the brain.
  • Cerebral Cortex: Outer nerve cell layer managing complex processes.
  • Cranial Nerves: Not part of CNS, manage head and neck functions.
  • Efferent vs Afferent Nerves: Motor (efferent, away from brain) vs Sensory (afferent, towards brain).

Additional Notes

  • Understanding neurotransmitters and their effects on behavior and drug interactions.
  • The importance of recognizing the role of the nervous system in both physical responses and mental health.

These notes should provide a comprehensive overview of the nervous system as covered in the lecture, including its structure, functions, and various components. These concepts will form the basis for understanding medical terminology related to the nervous system.

Full transcript