Nervous system -Divisions of the nervous system -The brain
The brain Which 3 interconnecting layers are forming the brain? the central core the limbic system the cerebral cortex (outer layer of cerebrum)
The functions of the central core Medulla? Regulates the basic life processes of breathing, heart rate, arousal (being awake and aware of external environment) and sleep Cerebellum ? Responsible for controlling balance, posture and movement
The functions of the limbic system The limbic system is part of the brain involved with what? processing information for memories influencing emotional states (e.g. anxiety, fear and aggression) influencing motivational states (e.g. hunger, thirst and sex drive)
The functions of the cerebral cortex? receiving sensory information making decisions in the light of experience coordinating voluntary movement. All that allows it to Be the centre of conscious thought recall memories alter behaviour in the light of experience.
Functional areas of the cerebral cortex and their job? The sensory areas receive information as sensory impulses from the body’s receptors The association areas analyse and interpret these impulses ‘make sense’ of them and ‘take decisions’ The motor areas receive information from the association areas and ‘carry out the orders’ by sending motor impulses to the appropriate effectors
Sensory areas, motor areas, association areas for language Language Concentration Planning and Problem solving
What is special about the location of the area for speech? It is found in one hemisphere only, for 90% of population in the left hemisphere.
The cerebrum is divided into two cerebral hemispheres How are the hemisphere connected? By a bundle of nerve fibers called the corpus callosum
Which hemisphere is responsible for what? Right hemisphere Personality, creativity, intuition, music, art and spatial abilities Left hemisphere Logic, maths, language, reading, writing, analysis
Which side of the brain controls the right side of the brain? The left side processes information from the right visual field and controls the right side of the body. The reverse is true of the right hemisphere
If a patient with a split brain (i.e. the corpus callosum has been cut) who has the speech area in the left hemisphere is asked to say what he sees in the picture below, what happens? He will be able to say that he sees a sunflower but won’t be able to say that he sees a frog. However, he will be able to draw a frog (and a sunflower if asked to do so!)
Spilt brain experiment CANo CANo