Neuroanatomy

• Cerebral cortex


  Largest part of the brain, occupies anterior and middle cranial fossae, divided into 2 hemispheres

  
• Cerebral cortex


  • Contains grey matter (cell bodies and dendrites of neurons)
  • Contains white matter (myelinated axons of neurons)
• Parts of the cerebrum

  • Cerebral cortex
  • White matter fibres
  • Deeper nuclei

  
• Lobes of the cerebral cortex

  Frontal lobe<|>Parietal lobe<|>Temporal lobe<|>Occipital lobe<|>Insula<|>Limbic lobe

  
• Sulci


  Grooves on the cerebral cortex
• Gyri

  Elevations between sulci on the cerebral cortex
• Lateral fissure

  1. Anterior horizontal ramus

  2. Anterior ascending ramus

  3. Posterior ramus
• Sulci of the frontal lobe

  • Central sulcus
  • Pre-central sulcus
  • Superior frontal sulcus
  • Inferior frontal sulcus
  • Lateral fissure

  
• Gyri of the frontal lobe

  • Pre-central gyrus
  • Superior frontal gyrus
  • Middle frontal gyrus
  • Inferior frontal gyrus (orbital part, triangular part, opercular part)

  
• Sulci of the parietal lobe


  • Central sulcus
  • Postcentral sulcus
  • Intra-parietal sulcus
  • Parieto-occipital sulcus
  • Lateral fissure
• Gyri and lobules of the parietal lobe

  • Postcentral gyrus
  • Supramarginal gyrus
  • Angular gyrus
  • Superior parietal lobule
  • Inferior parietal lobule
• Sulci of the occipital lobe


  • Lunate sulcus
  • Transverse occipital sulcus
• Gyri of the temporal lobe


  • Superior temporal gyrus
  • Middle temporal gyrus
  • Inferior temporal gyrus
• Sulci of the temporal lobe

  • Superior temporal sulcus
  • Inferior temporal sulcus
• Sulci of the medial surface

  • Callosal sulcus
  • Cingulate sulcus
  • Parieto-occipital sulcus
  • Calcarine sulcus
• Gyri and lobules of the medial surface

  • Cingulate gyrus
  • Medial frontal gyrus
  • Lingual gyrus
  • Paraterminal gyrus
  • Subcallosal gyrus
  • Paracentral lobule
  • Precuneus
  • Cuneus
  • Isthmus
• Sulci of the inferior surface

  • Orbital sulci
  • Olfactory sulcus
  • Collateral sulcus
  • Occipitotemporal sulcus
• Gyri and other structures of the inferior surface

  • Orbital gyri
  • Straight gyrus
  • Parahippocampal gyrus
  • Medial occipitotemporal gyrus
  • Lateral occipitotemporal gyrus (fusiform gyrus)
  • Frontal pole
  • Temporal pole
  • Uncus
  • Occipital pole
• Sulci of the insula

  • Circular sulcus
  • Central sulcus
• Gyri and other structures of the insula

  • Short gyri
  • Long gyrus
  • Limen
• Limbic lobe


  Not a true anatomical lobe, ring of cortical structures on medial surface overlying subcortical limbic structures, consists of parahippocampal gyrus, cingulate gyrus, and subcallosal gyrus
• Functional areas of the cerebral cortex

  • Motor areas
  • Sensory areas
  • Association areas

  
• Cerebral dominance (handedness)


  A specific cerebral hemisphere is dominant, associated with the preferred hand, determined before birth
• Functional areas of the frontal lobe

  • Primary (somato)motor area
  • Supplementary motor area
  • Premotor area
  • Frontal eye-field
  • Broca's (motor speech) area
  • Pre-frontal cortex

  
• Primary motor area


  Located in the pre-central gyrus, responsible for voluntary skilled movement on the opposite side of the body, supplied by ACA and MCA
• Supplementary motor area

  Located in the posterior third of the superior frontal gyrus, responsible for planning of complex/coordinated movements on the opposite side, mainly contralaterally active, supplied by ACA and MCA
• Premotor area


  Located in a thin strip between the primary motor area and frontal eye-field, responsible for sensory guidance of movement, controls muscles close to the axis of the body
• Frontal eye-field


  Located in the middle frontal gyrus, responsible for horizontal eye movements, bilaterally active, supplied by MCA

  
• Broca's area


  Located in the inferior frontal gyrus, responsible for motor speech/speech production in the dominant side, and emotional inflection in tone of voice in the non-dominant side, supplied by MCA
• Parts of the pre-frontal cortex

  • Medial part: inspiration area, motivation, spatial memory, focus
  • Lateral part: planning of activities, decision making, reasoning
  • Orbitofrontal part: impulse control, emotional processing, social cognition, personality expression

  
• The primary motor area has a homunculus, a segmental arrangement in which the body is represented (upside-down) showing disproportionate size of the cortex in different areas

  
• Functional areas in the frontal lobe


  Primary motor area<|>Supplementary motor area<|>Frontal eye-field<|>Pre-frontal cortex<|>Broca's area (motor speech)<|>Premotor area

  
• Functional areas in the frontal lobe (medial surface)


  Primary motor area<|>Supplementary motor area<|>Pre-frontal cortex

  
• Functional areas in the frontal lobe (inferior surface)


  Pre-frontal cortex<|>Cerebral cortex

  
• Primary (somato)motor area


  • Segmental arrangement in which the body is represented (upside-down)
  • Shows disproportionate size of the cortex in different areas
  • Area of cortex is proportional to degree of precision with which the movements can be executed

  
• Cerebral cortex


  Body representation: (upside-down)<|>Medial surface: lower limb<|>Superolateral surface divided into thirds: Superior third: trunk, Middle third: upper limb, Inferior third: head and neck<|>Blood supply: Anterior cerebral artery - lower limb, trunk; Middle cerebral artery - upper limb, head and neck

  
• Functional areas in the Parietal lobe

  • Primary (somato)sensory area
  • Sensory association area
  • Wernicke's area
• Primary (somato)sensory area


  Sensory area for general sensations (pain, temperature, touch...)
• Sensory association area

  Allows perception of shape, texture, size of objects; Identification of objects by feel; Conscious awareness of contra-lateral part of body
• Wernicke's area


  Association area for language: Angular gyrus - comprehension of written language, Supramarginal gyrus - comprehension of sound or spoken language