Neurological System

Neurological System Study Notes

Chapter Overview

  • The chapter covers the structure and function of the neurological system, consisting of the Nervous System divided into two main components:
    • Central Nervous System (CNS): Comprised of the brain and spinal cord.
    • Peripheral Nervous System (PNS): Connects CNS to the rest of the body.

Nervous System Components

  • Central Nervous System (CNS):

    • Brain:
    • Largest section of the brain, divided into two hemispheres.
    • Responsible for various body functions.
    • Sections of the Brain:
      • Cerebrum:
      • Largest section, handles higher brain functions.
      • Cerebellum:
      • Coordinates voluntary movements, balance, and posture.
      • Diencephalon:
      • Composed of the thalamus, hypothalamus, and epithalamus.
      • Acts as a processing center for conscious and unconscious inputs.
      • Brainstem:
      • Includes the medulla oblongata and pons.
      • Regulates basic body functions, heart rate, and respiratory functions.

  • Spinal Cord:

    • Protected by cerebrospinal fluid, which bathes the spinal cord and supports the brain within the cranium.
    • Meninges:
    • Composed of three protective layers that cover the CNS:
      • Pia Mater: Inner layer
      • Arachnoid Mater: Middle layer
      • Dura Mater: Outer layer

Autonomic and Somatic Nervous Systems

  • Autonomic Nervous System (ANS):
    • Controls involuntary functions.
    • Divided into two main branches:
    • Sympathetic: Activates fight-or-flight response.
    • Parasympathetic: Restores body to rest and digest state.
  • Somatic Nervous System:
    • Controls voluntary muscle movements and external sensory receptors.

Peripheral Nervous System (PNS) Details

  • Spinal Nerve Roots:
    • Named based on their exit points from the spinal column.
  • Sensory Patterns:
    • Dermatomes: Areas of skin supplied by specific spinal nerves for sensation.
  • Motor Patterns:
    • Myotomes: Muscle groups controlled by specific spinal nerves.
  • Grouping by Location:
    • Cervical C1-C8
    • Thoracic T1-T12
    • Lumbar L1-L5
    • Sacral S1-S5

Medical History & Physical Examination

  • Family History: Consider genetic factors that may affect neurological health.
  • Personal History: Previous nerve injuries or neurological illnesses.
  • Physical Examination Components:
    • Posturing Types:
    • Decorticate Posturing: Arms flexed, legs extended; indicates damage to cerebral cortex.
    • Decerebrate Posturing: Arms and legs extended; indicates damage to brainstem.
  • Additional Signs:
    • CSF or blood discharge from nose/ears.
  • Assessment Components:
    • Sensory and motor assessments.
    • Assessment of deep tendon reflexes.
    • Cranial nerve assessment.
    • Cognitive function assessment using standardized tools.

Neurological Pathologies

  • Strokes:

    • Types:
    • Ischemic: Blood clots or plaque block blood flow in the brain.
    • Hemorrhagic: Burst blood vessels in the brain.
    • Transient Ischemic Attack (TIA): Temporary disruption of blood flow, termed a “mini stroke.”
    • Signs & Symptoms:
    • Severe headache, facial weakness, unilateral weakness, poor balance, visual disturbances.
    • Risk Factors:
    • Family history, hypertension, diabetes, substance abuse, etc.
    • Prevention: F.A.S.T criteria (Face drooping, Arm weakness, Speech difficulty, Time to call emergency services).

  • Headaches:

    • Migraine:
    • Etiology poorly understood; triggers may include stress, lack of sleep, food.
    • Signs and Symptoms: Unilateral, throbbing pain, photophobia, nausea.
    • Cluster Headaches:
    • Intense pain around one eye, often accompanied by autonomic dysfunction (tearing, nasal congestion).
    • Sinus Headaches, Tension Headaches: Different presentations with their own signs.

  • Concussions:

    • Etiology: Impact or rotational forces; can occur with direct blows or whiplash.
    • Signs & Symptoms: Headaches, dizziness, confusion, behavioral changes, and various cognitive impairments.

  • Concussion Assessment and Management:

    • Multifaceted approach including sideline assessments for physical and cognitive states, along with gradual return-to-learn and return-to-sport strategies.

  • Post-Concussion Syndrome:

    • Signs and symptoms that persist for over 4 weeks following a concussion, treatment involves managing symptoms and ensuring rest.

  • Meningitis:

    • Bacterial Meningitis: Highly contagious, presents with severe symptoms and requires immediate medical intervention.
    • Viral Meningitis: Less severe, caused by viruses; supportive treatment is required.

  • Seizures:

    • Types of Seizures:
    • Petit Mal (absence seizures) characterized by brief lapses in awareness.
    • Grand Mal (tonic-clonic seizures) involve loss of consciousness and severe motor disruptions.

  • Management during a seizure: Keeping the environment safe, timing the seizure, and ensuring the person’s head is protected.

Recovery Position

  • Proper way to position an individual having a seizure, on their side to maintain airway clearance post-seizure.