Brain Unit 3 Behaviour, Populations and Environment
Brain
Unit 3
Behaviour, Populations and Environment
Learning Outcomes
• To learn about the structure of the brain
• To learn about the convoluted nature of the cerebrum
• To learn about the location of the discrete areas of the brain and their functions
• To relate the size of the discrete areas with the function they carry out
Evolution of the Brain
Brain Structure
Brain Structure
• Plasticity - Brain is flexible. If injured, the functions of the damaged part can be taken by unaffected parts.
• Sensory/ Motor areas - Brain receives information along sensory neurones from sensory receptors in eyes, ears, skin etc. It then sends out information along motor neurones to muscles or glands.
Cerebrum
• Convoluted (folded) which increases number of cell bodies
• 2 halves called cerebral hemispheres
• Controls conscientious thought, voluntary actions, determines personality etc
Areas of Cerebrum
Motor Homunculus
• Imaginary human whose body parts have been drawn in proportion to their mobility and fine motor control
• The more motor control needed, the larger the motor area required
Corpus Callosum
• Mass of fibres which separates cerebral hemispheres
• Transfers information from 1 hemisphere to the other
Cerebellum
• Attached to underside of brain
• Unconscious fine control of voluntary muscle movement and balance
Medulla Oblongata
• Connects brain to spinal cord
• Unconscious co-ordination of basic functions – breathing, heart rate, digestion, reflex actions
Medulla oblongata
EEG
• Electroencephalogram• records brain’s electrical
activities
Split-brain studies
• when a person’s corpus callosum has been cut
• exchange of information between cerebral hemispheres doesn’t occur
Brain Injuries
• Studies for brain injuries include:
• Phineas Gage – frontal lobe determines personality
• a man with visual agnosia mistook his wife for a hat
• soldiers with shrapnel wounds• people with brain lesions• Stroke sufferers
The Facts you need to know
p17
“in recent human evolutionary history ….”
to
“the cerebral hemispheres are ….”