Lecture 4: Development of the Periphery (unfinished) Flashcards
After the fusion fo the neural folds, what happens to neural crest cells?
They leave the dorsal aspect of the developing neural tube.
Neural cells migrate away from..?
the neural tube
cells form the nerual crest differentiate into what?
into a variety of neural and non-neural cell types.
neural crest stem cells can become?
BDNF - sensory neurones BMP - autonomic neurone Endothelin 3 - pigment cell neurkgulin - Schwann cells TGFB - smooth muscle
Presumptive sympathetic ganglion neurons migrate from ?
the developing neural crest and neural tube.
Presumptive sympathetic ganglion neurons form what and when?
They form 2 chains of sympathetic ganglia at 5 weeks.
where do neuroblasts migrate from?
migrate from the thoracic portion
what do neuroblasts supply?
supply structures in the head and neck and caudally to innervate structures in the lower body.
what do some neuroblasts form?
prevertabral ganglions or organ plexuses.
Spinal nerve fibers grow to innervate the ?
sympathetic ganglia
sympathetic ganglionic neuroblasts extend what to what/
extend fibres to their target organs.
Sympathetic plexuses are found where?
heart and lungs
where do Pre-ganglionic parasympathetic neurons project from ?
they project from the mesencephalon, rhombencephalon and sacral region of the spinal cord.
Pre-ganglionic parasympathetic neurons send axons along what?
They send axons along the paths of the cranial and somatic nerves.
what does the parasympathetic NS not contain?
chains of ganglia
ganglia arising from the PNS are generally ?
terminal or intramural.
The ENS forms from neural crest arising from ?
the rhomencephalon (vagal) and sacral regions of the spinal cord.
Ablation of the vagal section of the neural crest prevents formation of what?
enteric ganglia in the oesophagus, stomach, small and large intestine.
Ablation of the sacral section of the neural crest prevents formation of ?
enteric ganglia in the large intestine.
what’s a placode?
thickened patches of ectoderm that develop primarily into special sensory structures.
where do places derive from?
They are derived from a ectoderm around the neural plate
what are the 5 main placodes?
olfactory placode optic placode Adenohypophyseal placode otic placode Profundal/trigeminal placodes
what does the olfactory placode form?
the nasal olfactory epithelium
where does the optic placode lie?
lies on the surface, adjacent to the optic vesicle (which forms the retina) and form the lens.
