Chapter 4 - 'Brain Development In Infancy And Adolescence' Flashcards
How large is the brain compared to an adults at... Birth? Six months? Two years? 6? 21?
Birth - 25% Six months - 50% Two years - 75% 6 - 90-95% 21 - 100%
What areas of the brain develop first?
Areas controlling vital survival functions.
Hind brain to fore brain
Why does the brain enlarge so much from birth?
3 reasons?
The Production of Myelin through ‘myelination’
The growth of new neural connections through ‘synaptogenisis’
The branching of dendrites.
Which areas of the cerebral cortex are myelinated first?
Sensory neurons and then motor neurons.
What is synaptogenisis?
Synaptogenisis is the formation of new synapses between the brain’s neurons.
(The creation of new connection points between neurons)
How is synaptogenisis carried out?
Through the new formations of axon collateral and terminals as well as dendrites and dendritic spines.
Where does synaptogenisis occur quicker and why?
Occurs quicker in sensory neurons, motor neurons and lastly inter neurons. This is believed to allow the brain to have the ability to respond to all the new incoming sensations.
How fast is synaptogenisis after the first 15 months?
The amount of synapses by 15 months is tenfold.
What is the process of eliminating synaptic connections called?
Why does this happen?
Where does it occur first?
Synaptic pruning.
In order to ‘fine tune’ the areas of the brain.
Occurs first in sensory neurons and then last in inter neurons.
How long does synaptic pruning go for?
Amount of synapses in 3 year old vs adult?
Stops all together by 30.
40% less.
What is the last area of the brain to fully mature?
What is this area in charge of?
The prefrontal cortex is in charge of more advanced mental functions such as our ability to reason, plan ahead, organise, solve problems, make decisions and so on.
At birth, how many neurons does the brain have compared to an adults?
The same amount.
