Neurologic System

Neurologic System

1. Nervous system

   • Central Nervous System CNS
     • brain
       • Spinal cord
   • Peripheral Nervous System SNS
     • All nerve fibers outside brain and spinal cord
       • 12 Pairs Cranial nerves
         • 31 Pairs spinal nerves
   • Affarent messages from PNS to CNS. From sensory receptors
   • Efferent messages from CNS to muscles, glands, and autonomic nervous system. Govern organs and blood vessels.

2. Cerebral Cortex

   • Nerve cell bodies look like grey matter
     • lack myelin
       • Center human's highest functions
         • Governs thought, memory, reasoning, sensation, voluntary movement.
   • 2 hemispheres
     • 4 lobes
       • Frontal
         • Parietal
           • Occiptal
             • Temporal
               • Primary auditory reception center, hearing, taste, and smell.
                 • Wernicke's area, language comprehension.
                   • injury to dominate hemisphere, receptive aphasia. Can hear sounds/no meaning
             • Primary Visual receptor center
           • pre central gyrus primary sensation center.
         • personality, behavior, emotion, intellectual fxn,
         • Broca's area, motor speech in dominant hemisphere
           • Injury results in expressive aphasia

3. Basal Ganglia

   • bands grey matter deep within 2 hemispheres.
     • form subcortical-assoc motor system
       • extrapyramidal system
         • initiate coordinate movement autonomic assoc movements
           • ex. arm swing/ leg walk

4. Thalmus

   • Main relay system sensory pathways of spinal cord, cerebellum, basal ganglia, and brainstem
     • integrating system crucial to human emotions and creativity.

5. Hypothalmus

   • major respiratory center, basic vital fxns: temp, appetite, sex drive, heart rate, BP control., Sleep center.
     • anterior/posterior pituitary gland regulator
       • Coordinator of autonomic nervous system activity and stress response.

6. Cerebellum

   • coiled structure under occipital lobe
     • equilibrium, muscle tone
       • smoothes and coordinates movement. Does NOT initiate movement.

7. Brainstem

   • Central core of brain, mostly nerve fibers.
     • Cranial nerves III-XII originate from brainstem
     • Midbrain
       • Pons
         • Medulla

8. Spinal Cord

   • Occupies 2/3 of vertebral canal
     • myelinated bundles
       • mediates reflex, posture control, urination pain response

9. CNS Pathways

   • Sensory pathways
     • receptors in skin, mucous membranes, muscle, tendons and viscera
       • monitor conscious sensation, internal organ fxn, body position and reflexes.
         • 2 routes
           • anteriolateral or spinothalmic tract.
             • sensory fibers transmit sensation, pain, temp, crude/light touch
               • Fibers enter dorsal root & synapse w/a second sensory neuron
                 • Second order neuron fibers cross and ascend up spinothalmic tract to thalmus.
           • posterior/dorsal columns
             • Conduct sensation, position, vibration & localized touch
               • position, proprioception, vibration
                 • Fibers enter dorsal root, proceed up spinal cord to brainstem, synapse @ medulla w/second sensory neurons. Travel to thalamus synapse to sensory cortex
   • Motor pathways
     • upper motor neurons
       • lower motor neurons

10. PNS Pathways

    • Peripheral
      • Somatic
        • voluntary skeletal muscles
      • autonomic
        • smooth involuntary muscles, cardiac muscles, glands
          • mediates unconscious activity
            • fxns maintain homeostasis
      • carry input to CNS via sensory afferent fibers and deliver output from CNS via efferent fibers
        • Cranial nerves
          • Spinal nerves

11. Glasgow Coma Scale

    • normal score 15
      • eye open response
        • motor response
          • verbal response