Development of the Nervous system Flashcards
when does the brain start developing
in the 3rd week post conception
what do genes determine in the brain
sequence and evolution during neuronal proliferation, migration and reorganisation
development of dendtritic and axonal interconnections
the development of synapses, receptors, and neurotransmitters
when is the embryonic period
conception to week 9
when is the fetal period
week 9 to 40/42
what is gastrulation
process that results in the development of a three layered embryo
what does the ectoderm form
skin nails and neural tissue
what does the mesoderm form
muscle, bone, cartilage, vascular system
what does the endoderm form
gut and respiratory system
when does neural tube form
day 20-27
what does the hollow centre of the neural tube become
ventricular system and central channel of the spinal chord
what becomes the brain
the anterior/rostral tube
what becomes the spinal chord
the caudal tube
what is the importance of neural patterning
creates distinct functional areas in the brain
when does brain develop its folded appearace
fetal pariod (week 9 to term)
why are the development of gyri and sulci needed
to accommodate the proliferating neuronal populations
what cells can continue to divide within the brain in the fetal period
the progenitor cells (cells divide to make a progenitor cell and a neuron)
how do neurones migrate
somal translocation with radial glial guides
what happens when neurones reach their target cortical regions
develop processes which allow them to communicate and transmit information
what do axons do
transmit signals from neurones
what do dendrites do
gather info and transmit to neurones
how many neurones will die and how many connections will be eliminated in normal brain development
50%
what happens postnataly in brain development
proliferation and migration
myelination
describe myelination
Oligodendrocyte progenitor cells (OPCs) develop processes which wrap around axons= myelin sheaths
what is the role of myelin sheaths
increase axonal conduction rates dramatically, maintain axonal integrity, survival, neuronal size and axonal diameter