L9 - MSK - Neurulation and Neural Crest Flashcards
What germ layer does the Notochord come from?
Ectoderm
*Red
What does Neural Plate form?
What induces it’s formation?
What germ layer is it from?
Forms CNS
Induced by Notochord
From Ectoderm (red)
What layer is closest to the mesoderm?
Somatic Layer
What comes from the Neural Crest?
What germ layer is Neural Crest from?
What germ layer does it act like?
Bone, Cartilage, Heart
From ectoderm
Acts like mesoderm
What releases Sonic Hedgehog?
The Notochord
What does Neuroectoderm make?
Neural Plate
Neural Groove
Neural Folds
Neural Tubes
How does the Neural Tube Closure occur?
Starts to zip up in the middle and moves towards the ends
What does Primary Neurulation do?
Brain to lumbar region of spinal cord
What does Secondary Neurulation do? and when?
Day 20 to Day 42
Caudal Eminence and then becomes spinal cord
What day does the Rostral Neuropore close?
Day 25
What day does the Caudal Neuropore close?
Day 28
Why does the Rostral Neuropore close first?
Rostral is brain to lumbar region.
Brain is more important. So more blood goes to head and arms so they will develop first.
What type of cells and tissues arise from Neural Crest?
- Neurons
- Supporting Cells
- Pigmenting Cells
- Endocrine Cells
- Ectomesenchyme
What make Neurilemma cells?
Neural Crest
What makes Enamel and Dentin?
Neural Crest
Neural Crest Derivative Cells
*Sensory Neurons come from Neural Crest*
- Spinal Ganglion
- Autonomic Ganglia
- Schwann Cells / mylenating the PNS
- Arachnoid and Pia Mater
- Hair/Skin - Pigment
- Thyroid C-Cells
- Adrenal Gland Cells
- Cartilage of head and neck
- Parts of heart, eye, teeth
Problem with what cells lead to DiGeorge Syndrome?
Neural Crest cells
- Neurocristopathies
What causes Hirschsprung’s disease? (aganglionic colon (blockage))
Neurocristopathy
Problem with Neural Crest Cells
Neurocristopathies = problems with Neural Crest Cells
examples?
Cleft palate/lip
Heart defects
Eye Defects
DiGeorge
Hirschsprung’s
What is Spinal Bifida occulta?
What causes it?
What are the symptoms?
Who does it affect?
- hidden
- caudal neuroport finally closed but disrupted
- unfused vertebral arch
- bifebed spinous processes
- usually no problems
- tuft of hair on small of back
- 10% of population
What is Meningocele?
What causes it?
Symptoms?
Vertebral arches present?
Defects?
Congenital Neural Tube Defects: Spinal Cord
- Failure of Caudal Neuroport to close in timeley manner
- finally closes, by may or may not be covered by skin
- Vertebral arches did NOT form
- meninges herniate out into a cyst like sac
- may or may not have defects
What is Meningomyelocele?
Cause?
Arches?
Skin?
Defects?
Congenital Neural Tube Defect: Spinal Cord
- failure of caudal neuroport to close
- no vertebral arches
- meninges herniate into sac
- covered with membrane
- motor and sensory defects
What is Myelocele (myeloschisis)?
- most severe
- Conginetial Neural Tube Defect: Spinal Cord
- Spinal cord exposed to environment
- no vertebral arches
- motor and sensory defects
- SOL
- Spina bifida occulta
- Meningomyelocele
- Anencephaly
- Encephalocele
