Brain

Brain

1. Cerebral Cortex

   • Structure of the cerebral cortex
     • outer layer of the 2 cerebral hemispheres (offers no protection to the brain, that is the roll of the skull)
     • it is 2 to 5mm thick
     • it is convoluted (folded, which gives brain a greater surface area)
     • each hemisphere can be divided into 4 anatomical areas called cortical lobes
   • Functional areas of the cerebral cortex
     • sensory areas
       • processing of sensory info received by various senses i.e smell, touch etc
     • motor cortex
       • controls/processes motor info/body movements
     • association areas
       • integrate sensory & motor info: higher mental processes such as language, thinking and problem solving

2. Corpus collusum

   • located between the 2 cerebral hemispheres
   • consists of 200 million nerve fibres

3. Frontal lobe

   • contains primary motor cortex (back of frontal lobe)
     • initiates voluntary movements of the skeletal muscles
       • specific parts are responsible for specific areas of body
         • upper part of PMC is responsible for lower parts of body
           • Movements of hands and mouth take up largest areas because they're capable of more complex and fine movements
   • contains brocas area
   • the association area is at front of lobe, this area is more involved in cerebral activities such as inititative, planning, judging and reasoning
   • responsible for speech and expression of emotion
   • damage to frontal lobe could:
     • affect body movements
     • damage to left f.l might cause loss of motor function of right foot and vice versa
     • alterations to personality and emotional expression
     • diminish mathematical ability

4. Broca's area

   • know as speech production centre
   • located in left frontal lobe
   • controls muscles required for speech
   • responsible for clear, fluent speech
   • located next to motor cortex, which controls the facial and throat muscles
   • also concerned with meaning of words, structure of sentences, parts of speech such as conjunctions, adjectives and prepositions
   • damage to broca's area can:
     • cause broca's aphasia
       • a person is only capable of short sentences, mainly verbs and nouns
   • combines sounds into words

5. Temporal lobe

   • understanding speech
   • if damaged cannot understand sentences
   • involved with auditory perception
   • plays important role in memory, ability to recognise faces and memories
   • contains primary auditory cortex
   • contains wernickes area

6. Parietal Lobe

   • receives and processes sensory info and skin senses
   • sends info to other parts of the brain
   • contains somatosensory cortex
     • allows us to perceive bodily sensations (touch, pressure and temp, info about muscles)
   • left side info is received and processed by the right primary somatosensory cortex and vice versa

7. Occipital Lobe

   • devoted to the sense of vision
   • contains primary visual cortex
   • info comes to primary visual cortex from visual sensory receptors
   • the left half of each eye (receives visual sensory info from the right half of the visual field) sends info to the visual cortex in the left occipital lobe and vice versa

8. Wernicke's area

   • Wernick's apashia
     • don't know what they are saying doesn't make sense
   • involved in speech production and has a crucial role in comprehension of speech
   • cant process what a word means unltil info has been processed by wernicles area
     • also vital for locating words from memory to express intended meanings when we speak and write

9. Spatial neglect

   • damage to the right parietal lobe causes spatial neglect
   • attentional disorder where individuals fail to notice anything either on their left or right side
     • mostly neglect left side of their world
   • fails to attend to the left side of their environment
   • tend to behave as if that one side of their world does not exist
   • happens to stroke or accident victims who have damage to the rear area of the parietal love of the right hemisphere

10. Split brain

    • people who have seizures undergo a split brain surgery that involves surgically cutting the corpus callosum to prevent seizures from occuring
    • disconnects one hemisphere of the brain from the other
    • because the corpus callosum has been cut, they are unable to say what they see on their left side although they can see it. this is because speech is a specialisation of the left hemisphere and the corpus callsum was unable to exchange info between the two hemispheres
    • however they are able to draw what they saw and then identify it after drawing it, they could also identify it with their left hand on a screen.