Areas of the brain
- The cerebrum - this is the largest part of the brain and is made up of 2 hemispheres, this is controls the voluntary muscle, memory and imagination. it makes up 85% of the brains mass.
- The corpus callosum - this is a thick band of nerve fibres that joins the two hemispheres of the cerebrum and allows the transfer of information between them
- The cerebral cortex - this is the outermost layer and is made up of a thin layer of nerve cell bodies, this is the more highly developed part of the brain and plays a role in the conscious thought, overriding reflexes and reasoning and judgement. This then has three regions within it (may be others too) which are the sensory area, the motor area and the association area.
- The sensory area - this is the area that recieves impulses from receptors around the body
- The association area - this is where judgement is made, previous experiences are compared with the input and a rational and appropiate response can be sent
- The motor area - this is where the impulses are sent to the effecors (muscles/glands)
- The cerebellum - this controls the finer movements that are nonconscious e.g. driving a car, walking (examples include antagonistic muscle movement, changing the body's position quickly, judging the positioning of objects, the tensioning of muscles to manipulate tools). It carries impulses to the motor neurones to cause an effect on the effectors and explains why we go into 'autopilot' mode
- The areas that the cerebellum recieves information from - the retina, the balance organs in ears, specialised fibres called spindles in muscle fibre and the joints
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- The brain is protected by bones of the cranium and membranes called meninges. They secrete a fluid that provides protection and cushioning of the brain.
- The brain has a blood-brain barrier that means that the capillaries in the brain are not as 'leaky' as those that are found elsewhere in the body. This prevents potentially damaging substances that are found in the blood (like ammonia, alcohol and drugs).
- The cerebral cortex is responsible for the features that make us human e.g. speech, emotions, logical thought.
- We can use MRI or PET scanning to understand how various parts of the brain work
- Association areas are involved in what the sense organs tell us about the position of different parts of the body, the planning of movements and actions (decided in the frontal lobe) and emotions and memory (called the limbic system).
- The limbic system contains the hippocampus which is involved in memory storage
- The left hemisphere is used more for the use of language and understanding it - Broca's area is involved in speaking the language whereas the Werniche's area is responsible for understanding it.
- The right hemisphere is used more in the non-verbal processes such as visualising objects and recognising faces
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- The hypothalamus - this is the region that is associated with controlling the homeostatic conditions within the body (autonomic nervous system). It controls the pituitary gland which secretes hormones as a result in the change of internal conditions (from the thermoreceptors, osmorereceptors or chemoreceptors).
- The medulla oblongata - this controls the non-voluntary muscles such as cardiac muscle or involuntary muscle. This means it can manipulate and regulate the rate of the heart beat, the depth of the breathing and the rate of the breathing
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