L3- Introduction to the CNS

• Guillain-Barre syndrome is an auto-immune response to PNS myelin. Attacks PNS myelin - schwann cells. Symptoms include muscle paralysis, lack of coordination, and loss of sensation
• Multiple sclerosis (MS) is an auto-immune degeneration of myelin in the CNS. Symptoms include lack of muscle coordination, movement and loss of sensation. Symptoms may vary depending on the area of myelin damage
• Neurons do not divide and regenerate therefore, damage to neurons results in permanent damage
• Nerve processes (axons) can regenerate. Distal to the injury will degenerate and be cleaned up by macrophages. Axon will sprout new ends and the myelin sheath will guide the new process. Regeneration is approximately 1.5mm per day
• Regeneration of damaged axons does not return to 100% full function after regeneration
• Label this diagram of loss of sensory or motor function

  A) parathesia

  B) numb

  C) paresis

  D) paralysis

  
• The PNS divides into sensory and motor

  motor divides into somatic and autonomic

  autonomic divides into sympathetic and parasympathetic
• Fissures are large crevasses which divide the cerebral hemispheres between different lobes

  • transverse cerebral fissure - divides cerebral hemispheres from cerebellum
  • longitudinal fissure - divides right and left cerebral hemisphere
• Sulci (sulcus) are shallow grooves on the surface of cerebral hemispheres
• gyri (gyrus) are twisted ridges or surface folds
• Label the fissures

  A) transverse cerebral fissure

  B) longitudinal fissure

  
• The frontal lobe is responsible mainly for motor function

  • voluntary movement
  • planning movement
  • eye movement
  • speech production
• The temporal lobe is mainly responsible for understanding

  • auditory cortex
  • olfactory cortex
  • recognition of objects, words, faces
• The parietal lobe is mainly responsible for sensory functions

  • processes sensory stimuli
  • spatial awareness
  • understanding speech
• The occipital lobe is the visual cortex of the brain
• The insula processes general visceral sensory and taste
• Label the lobes of the cerebral hemispheres

  A) frontal lobe

  B) lateral fissure

  C) temporal lobe

  D) parietal lobe

  E) central sulcus

  F) parieto-occipital sulcus

  G) occipital lobe

  H) insula

  
• Label the spinal nerves

  A) dorsal root

  B) ventral root

  C) spinal nerve

  D) dorsal ramus

  E) ventral ramus

  F) rami communicantes

  G) sympathetic trunk

  
• Spinal nerves in each vertebral region

  • 8 cervical nerves
  • 12 thoracic nerves
  • 5 lumbar nerves
  • 5 sacral nerves
  • 1 coccygeal nerve
• The end of the solid spinal cord is called the conus medularis which then turns into the cauda equina