Dvelopment of the Nervous System Flashcards
Which cells develop into the CNS
Neuroepithelium (wall of the neural tube)
Which structure develops into the PNS during early development
Neural crest
Describe the early development of the nervous system
- The neural plate folds inwards towards the notochord to form the neural groove/fold
- The fold closes off to form the neural canal with the neural crests on either side
neural crest = PNS/ neuroepithelium = CNS
What are the layers involved in the early development of the nervous system
Neural plate/Ectoderm
Notochord/Mesoderm
Endoderm
What does the mesoderm develop into
Mesodermal somite
What are the 3 main types of cells the neuroepithelium can differentiate into
Glioblasts
Ependymal Cells
Neuroblasts
What are the types of glioblasts and their functions
Astrocytes = involved in neurotransmission, support and the blood-brain barrier
Oligodendrocytes = provide myelin sheaths in the CNS (speed up action potentials via saltatory conduction)
What is the function of ependymal cells
Line the ventricles and central canal of the brain
What 4 cell types do neural crest cells differentiate into
Sensory neurones (dorsal root ganglia)
Schwann cells
Postganglionic autonomic neurones
Non-neuronal derivitives (melanocytes)
Describe the structure of the neural tube
Describe the proliferation and differentiation of the neuroepithelium
Cells actively divide on the inside of the neural tube
Developmental cells (and ventricles) are in the ependymal layer where they then migrate to the grey matter. Axonal projections are in the white matter
what is the difference between matter organisation in the spinal cord and brain
Brain = grey matter outside and white matter inside
Spinal chord = grey matter inside and white matter outside
What controls differentiation
Signalling molecules secreted by surrounding tissue
> control axonal growth and migration (through attraction and repulsion)
What do signalling molecules depend on
Concentration gradient and timing
