L4: Nervous system development Flashcards
What is the Neural plate and at what point of gestation is it formed?
Primitive neural tissue created as the Ectoderm thickens lengthways, formed by day 18 of gestation.
What is the Neural groove and at what point of gestation is it formed?
The Neural groove is formed when the neural plate flattens and folds in the middle, formed by day 21 of gestation.
What is the Neural tube and at what point of gestation is it formed?
The Neural tube is formed when the neural groove folds completely in the middle creating a tube, formed by day 23 of gestation.
What is Anencephaly?
A Neural tube defect where it fails to completely close over resulting in an under-developed brain and skull, most babies do not survive past the first week after birth. Affects 5/10,000 births.
What is Neurogenesis?
Cell birth of Neurons. Stem cells develop into neuroblasts then into neurons in the Neural tube.
What is cell migration?
Newly formed cells move from the neural tube to their correct destination in the nervous system. They travel along radial glial cells which act as guides.
What is cell differention?
When cells reach their destination and begin to express particular genes. This is where we acquire characteristics and cells either remain neurons or become glial cells.
What is cell maturation?
When dendrites and axons grow on the cell forming a Neuron.
What is Synaptogenesis?
The formation of synapses, continues after birth.
What is Myelination?
The process when Axons get wrapped in a fatty sheath, this speeds up the conduction of electrical signals.
What is Synaptic Pruning?
Cell re-arrangement and the deletion of non-communicating neurons.
What is the definition of epigenetics?
The combination of environment and genes (when intrinsic and extrinsic factors react).
What is experience driven neural activity?
Extrinsic factors that affect how the brain develops e.g. Maternal behaviour, enriched environment.
What are the two types of Demetia?
1) Non-degenerative: Caused by problems in the cardiovascular system
2) Degenerative: Caused by problems in the nervous system, Genetic transmission.
What is Alzheimers?
A degenerative dementia that accounts for 65% of all Dementias. It is the atrophy of the temporal and frontal lobes, also caused by changes in the Hippocampus. Having the Apoe4 gene is considered a high risk for Alzheimers. Symptoms: loss of recent memory that can progress into not being able to answer basic questions. No treatment currently.
