Central Nervous System Functions Quiz

Learning Objectives

• Students will be able to identify pertinent neurological system history questions.
• Students will be able to obtain a neurological system history.
• Students will be able to perform a physical assessment of the neurological system.
• Students will be able to differentiate between normal and abnormal findings.
• Students will be able to document neurological system findings.

Structure and Function of the Nervous System

• The Nervous system is divided into:
  • Central Nervous System (CNS): Brain and spinal cord
  • Peripheral Nervous System (PNS):
    • Cranial nerves (12 pairs)
    • Spinal nerves (31 pairs)
  • Autonomic Nervous System (ANS): Sympathetic and parasympathetic divisions.
• Nerves carry information to and from the CNS:
  • Sensory (afferent) messages from sensory receptors to CNS.
  • Motor (efferent) messages from CNS to muscles and glands.

Central Nervous System (CNS)

• The CNS consists of:
  • Cerebrum (or cerebral cortex)
  • Brainstem
  • Cerebellum
• Cerebral Cortex:
  • Center for higher-level functions (memory, reasoning, sensation), and voluntary movement.
  • Divided into four lobes:
    • Frontal: Personality, behaviour, emotions, and intellectual function.
    • Parietal: Sensation
    • Temporal: Hearing, taste, and smell.
    • Occipital: Vision
• Brainstem:
  • Midbrain: Anterior part of the brainstem, contains motor neurons and tracts.
  • Pons: Contains ascending sensory and descending motor tracts.
  • Medulla: Contains vital autonomic centers (respiration, heart, and gastrointestinal function) and cranial nerve nuclei (VIII-XII).
• Cerebellum: Located under the occipital lobe; coordinates voluntary movements, equilibrium, and muscle tone.

Spinal Cord

• Extends from the upper border of the first cervical vertebra to the lower border of the first lumbar vertebra.
• Primary pathway for messages between peripheral areas of the body and brain.
• Encased and protected by meninges and cerebrospinal fluid.
• Protected by the bony vertebrae of the spine.

Peripheral Nervous System (PNS)

• Consists of:
  • Spinal nerves: 31 pairs (both efferent and afferent nerves); named after the region of the spine they exit (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal).
  • Cranial nerves: 12 pairs.

Autonomic Nervous System (ANS)

• Contains motor neurons that regulate visceral organs and affect smooth, cardiac muscles, and glands.
  • Sympathetic division: Controls fight-or-flight reactions.
  • Parasympathetic division: Restores and maintains normal body functions.

Subjective Data

• Headache?
• Head injury?
• Dizziness/vertigo/syncope (temporary loss of consciousness)?
• Seizures (altered or loss of consciousness, involuntary muscle movements)?
• Tremors (involuntary shaking)?
• Weakness (including paresis and paralysis)?
• Incoordination (balance problems when walking)?
• Dysmetria (inability to control distance, power, and speed of muscular action)?
• Numbness or tingling (Paresthesia)?
• Difficulty speaking (dysarthria or dysphasia)?
• Past history of stroke, spinal cord injury, meningitis, encephalitis, or congenital defects?

Objective Data

• Sequence for Complete Neurological Examination:

  • Mental status
  • Cranial nerve function
  • Sensory function
  • Motor function
  • Reflexes

• Mental Status- ABCT:

  • Appearance, posture, body movements, dress, grooming, hygiene
  • Behavior: Level of consciousness, facial expression, speech, mood, affect
  • Cognitive function: Orientation (time, place, person), attention span, recent and remote memory
  • Thought process and perception: Thought process and content, perceptions, screening for anxiety, depression, and suicidal thoughts.

• Cranial Nerves (specific tests for each nerve):

  • I (Olfactory): Smell.
  • II (Optic): Vision (acuity and fields).
  • III (Oculomotor), IV (Trochlear), VI (Abducens): Eye movement, pupil reactions.
  • V (Trigeminal): Motor (jaw muscles), Sensory (face).
  • VII (Facial): Facial expressions, taste.
  • VIII (Acoustic/Vestibulocochlear): Hearing and balance.
  • IX (Glossopharyngeal), X (Vagus): Swallowing, taste, gag reflex.
  • XI (Spinal Accessory): Shoulder and head movement.
  • XII (Hypoglossal): Tongue movement.

• Sensory Function:

  • Pain: Sharp vs. dull sensation.
  • Light touch
  • Vibration
  • Position (Kinesthesia)
  • Stereognosis
  • Graphesthesia
  • Extinction

• Motor Function:

  • Muscle size, strength, tone, involuntary movement
  • Cerebellar function (Coordination and skilled movements tests and balance tests)

• Reflexes:

  • Deep tendon reflexes: Biceps, Triceps, Brachioradialis, Quadriceps, Achilles.
  • Superficial reflexes: Plantar.

• Neurologic Re-check:

  • Level of consciousness
  • Motor function
  • Pupillary response
  • Vital signs
  • Glasgow Coma Scale (GCS)

• Sample Charting (both subjective and objective data): Includes examples.

Abnormal Findings

• Muscle Tone: Flaccidity (decreased tone) or Spasticity (increased tone).
• Muscle Movement: Paralysis (decreased or loss of motor power); different types of paralysis (e.g., monoplegia, hemiplegia, etc.). Tremor (involuntary muscle contractions).
• Gait: Spastic hemiparesis, scissors gait, cerebellar ataxia, steppage or footdrop.
• Postures Decerebrate rigidity, decorticate rigidity.
• Meningeal irritation: Brudzinski's and Kernig's signs.