Development Of The Nervous System Flashcards
What is the neural plate? When is it noticeable in development?
A patch of cells on the dorsal surface of the human embryo after 18 days
What is the neural groove?
A groove developing down the center of the neural plate
What is the neural tube? What does it develop from?
Fluid filled tubes that developed from the neural groove
What is the neural crest?
Cells that break away from the edges of the neural plate. It is dorsal and lateral to the nerual tube
What do the neural crest and tube develop into?
Crest into PNS
Tube into CNS
What type are cells are present in the neural plate? What does this mean?
They are totipotent, can develop into any lands of cell
What are the six stages of early neural development?
Proliferation, migration, aggregation, process growth and synapse formation, neuron death, myelination
What occurs in proliferation? Where?
Cell division at the region of the neural tube adjacent to its fluid filled interior
What occurs during migration?
New cells travel to their specialized location along a temporary network of radial glial cells
What occurs during aggregation?
Neurons align themselves to form specific neural structures
What occurs during process growth and synapse formation?
Axons and dendrites grow out from the developing neurons and establish synaptic contacts
What is the growth cone? What is its function? When is it present?
At the tip of each dendrite it directions the growth of axons and dendrites to appropriate targets that is present during development
Is neuron death random in development?
No, neurons that have not developed efficient or effective synaptic contacts are most likely to die
Does neural proliferation occur at the same rate along the neural tube?
No, it is most present at the anterior end
What are the three swellings of the neural proliferation called?
Forebrain (prosencephalon) , midbrain (mesencephalon), hindbrain (rhombencephalon)
What are the five brain divisions present at week 5 of development?
Telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon
What two divisions does the forebrain develop into?
Telencephalon and diencephalon
What division foes the midbrain develop into during development?
Mesencephalon
What two divisions does the hindbrain develop into during development?
Metencephalon and myelencephalon
What is the chemo affinity theory?
Each postsynaptic target releases a specific chemical label and growing axons follow it up its concentration gradient
What is the blueprint theory?
Axons are programmed to follow particular trails through developing nervous systems
What is the pioneer growth cone?
First growth cone in the bundle of axons to reach the target, leader of the pack
What is fasciculation in axon growth?
The tendency for growing axons to grow along the same path as their neighbors
Which of the five divisions make up the cerebral hemispheres?
Telencephalon
