Brain Development Flashcards
What is morphogenesis?
biological processes that causes a cell, tissue or organism to develop it’s shape
Stages of prenatal development of the brain
fertilisation
germinal
Embryonic
Fetal
Birth
What is the Germinal stage?
first stage of prenatal development that doesn’t involve direct development of the brain but instead formation of zygote that contains DNA
What is the Embryonic stage?
when brain forms an embryonic structure called neural tube which develops into spinal cord
What is the fetal stage?
where brain undergoes significant changes
What is 1 characteristic of the early brain?
a tube
known as neural tube
What is the Prosencephalon?
front part of the brain
forebrain
What is the Mesencephalon?
midbrain
What is the Rhombencephalon?
hindbrain
Neural development develops in these stages…
- cell proliferation
- cell migration
- cell differentiation
- programmed cell death (apoptosis)
- synaptic elimination / rearrangement
What is cell proliferation?
massive production of cells through cell growth and division (2-4m of gestation)
continues until birth
What is cell migration?
Immature neurons migrate to reach target layer (this creates layers of cortex)
new created cells travel through embryonic brain through ‘ladder’
What is cell differentiation?
all neurons comes from precursor cells (undifferentiated cells)
when they migrate, they also differentiate
neural progenitor becomes neuron
glial progenitor becomes glia
What happens to the axon as cells differentiate?
axons extend to find appropriate target
top of axon is guided by special proteins which are repulsed by others until they find neurons to connect with
What is apoptosis?
programmed cell death
discarded neurons that didn’t connect with others
input neurons find target neurons and some miss target so slowly disappear
What is synaptic elimination?
eliminate synapses (wires) that don’t receive signal
crazy wiring = not efficient
What is vision like in infants?
immature
(at 6 months perception is blurry)
only see world in 2 dimension
What is face perception like In infants?
infants have slower timing than adults but eletrical pattern when processing visual stimuli is the same
What is sound perception like in infants?
foetus can perceive external sounds
newborns can discriminate mothers voice and recognise songs
starts slow then rapidly evolves
What is language like in infants?
it’s prewired
What is plasticity?
brain’s ability to reorganise and adapt
Key biological changes in adolescent
physical
bone growth
increase in muscle mass and strength
rapid growth in puberty
Key psychosocial changes in adolescent
personality
adopts social duties
own decisions and choices
shift from dependence to independence
What’s the most important factor of brain development in adolescence?
wiring of new connections between cells which makes biggest transformation
brain forms new synapses for synaptic density
