5. CEREBRUM

• Cerebrum


  The largest part of the brain
• Cerebrum


  • Divided into 2 parts (halves) called the left and right cerebral hemispheres
  • The 2 hemispheres are connected by a bridge of nerve fibres called the corpus callosum
  • The right half controls the left side of the body, the left half controls the right side of the body
• Cerebral cortex


  The outer surface of the cerebrum, also called grey matter, where nerve cells make connections (synapses) that control brain activity
• White matter


  The inner area of the cerebrum containing the insulated (myelinated) bodies of the nerve cells (axons) that relay information between the brain and spinal cord
• Cerebral cortex


  • Highly wrinkled, which increases the surface area and amount of neurons
  • The cerebral hemispheres are separated by the longitudinal cerebral fissure
  • The surface has folds or gyri separated by sulci or deeper fissures
• Main sulci and fissures

  • Central sulcus
  • Lateral sulcus
  • Parieto-occipital sulcus
  • Calcarine sulcus
• Cerebral lobes


  • Frontal (front)
  • Parietal (top)
  • Temporal (side)
  • Occipital (back)
• Frontal lobe


  • Controls movement, speech, behaviour, memory, emotions and intellectual functioning (thought processes, reasoning, problem solving, decision making, planning)
• Motor cortex


  • Sends signals (motor neurons) to tell our body to move
• Broca's area


  • Controls the muscles in our mouth involved in speech
• Parietal lobe


  • Controls sensations (touch, pressure, pain, temperature) and spatial orientation (size, shape, direction)
• Sensory cortex


  • Responsible for feeling touch sensations from our body
• Temporal lobe


  • Controls hearing, memory and emotions, and the left temporal lobe controls speech
• Wernicke's area


  • Responsible for interpreting both written and spoken speech
• Occipital lobe


  • Controls vision
• Arterial blood supply to the brain

  • Internal carotid arteries
  • Vertebral arteries
• Internal carotid arteries


  • Provide blood to most of the cerebrum
  • Divided into anterior cerebral artery (supplies midline cerebral circulation) and middle cerebral artery (supplies lateral surface of cerebral hemisphere)
• Vertebral arteries


  • Provide blood to occipital and inferior temporal lobes and brain stem
  • Form basilar artery which branches into anterior inferior cerebellar artery, superior cerebellar artery (provide blood to pons and cerebellum), and posterior cerebral arteries (supply midbrain and inferoposterior cerebrum)
• The carotid and vertebrobasilar arteries form the Circle of Willis at the base of the brain, from which the anterior, middle and posterior cerebral arteries arise and travel to all parts of the brain