Neurulation and Neural Crest Flashcards
What is meningocele spina bifida?
spinal cord in correct place; cyst of CSF and meninges outside of body; pts may or may not have deficits
What vitamin deficiency causes spina bifida?
folic acid
What does the ectoderm just lateral of the neural groove (medium amount of SHH) turn into?
neural crest –> migrates down to become spinal ganglion
What does the most medial ectoderm above the notochord become?
neural groove –> neural tube (neuroectoderm)
What are cranial neural crest derivatives?
neurons and glia of cranial gangia
cartilage and bone
connective tissue
What does the posterior part of the pituitary gland come from?
neural tube
What is the pachymeninx?
What is it made of and give rise to?
structure that gives rise to DURA mater
made of MESOderm
What are trunk neural crest derivatives?
pigment cells
sensory neurons and glia
sympathoadrenal cells
schwann cells
What germ cells do pigment cells come from?
neural crest
What is the region of secondary neurulation? What happens there?
caudal eminence: fuses with caudal neuropore –> lumbar and coccyx regions
What tissue gives rise to the arachnoid and pia mater?
neural crest
What is encephalocele?
what is it due to?
cyst on head; can be with or without brain tissue
Due to failure of rostral neural pore closure
What does the anterior part of the pit gland come from?
surface ectoderm
What does the most lateral ectoderm become?
surface ectoderm –> developing epidermis
What germ layer do epithelium of GI tract, liver, pancreas, and bladder come from?
endoderm
When does the caudal neuropore close?
day 28
What is myelocele spina bifida?
open spinal cord out of body; motor and sensory deficits
What is memingomyelocele spina bifida?
neural tube/spinal cord, meninges, and csf are protruding out of body; motor and sensory defects
What germ cells does the retina come from?
neural tube
When does the rostral/ cephalic neuropore close?
day 25
What is anencephaly?
What is it due to?
loss of neocortex and calvera (open brain); incompatible with life
due to failure of rostral neural pore closure
What is the meninx primitiva?
What is it made of?
structure that gives rise to the meninges (dura, arachnoid, pia)
made up of sclerotome from mesoderm and neural crest cells
What is the significance of alpha fetoprotein in spina bifida
levels of alpha FP increase when there are neural tube defects –> can be detected in amniocentesis
What is spina bifida occulta?
least severe spina bifida; vertebral arch isn’t closed and there is often a tuft of hair; no symptoms
What germ layer do epithelial parts of the trachea, bronchi, and lungs come from?
endoderm
What is hirschspring’s disease/aganglionic colon?
defect where autonomic sensory nerves don’t innervate the colon –> can’t poop and colon keeps expanding
problem with trunk neural crest cell migration
What signal does the notochord release to induce the neural plate?
Sonic Hedgehog
What types of nerves come from neural crest?
SENSORY and cranial
What germ layer does the pharynx and thyroid gland come from?
endoderm
