Embryology Flashcards
What does the notochord become?
nucleus pulposus
What does the neural plate become?
neural tube and neural crest cells
What do the neural crest cells become?
PNS neurons
Schwann cells
What does the neuroectoderm become?
CNS neurons
ependymal cells
oligodendroglia
astrocytes
What does the mesoderm become?
microglia
What is the pathogenesis of spina bifida?
neuropores fail to fuse (4th wk) –> persistent connection b/t amniotic cavity and spinal canal
What biomarkers will be seen before birth?
elevated alpha-fetoprotein in amniotic fluid and maternal serum
What physical finding is associated with spina bifida occult?
tuft of hair or skin dimple at level of bony defect
What is anencephaly?
malformation of anterior neural tube –> no forebrain, open calvarium
What disease is anencephaly associated with?
maternal diabetes (type I)
Maternal supplementation with folate decreases a baby’s risk of what diseases/conditions?
spina bifida
anencephaly
What is holoprosencephaly?
failure of left and right hemispheres to separate
What is the hypothesized pathogenesis of holoprosencephaly?
mutations in sonic hedgehog signaling pathway
What is Chiari II (Arnold-Chiari malformation)?
significant herniation of cerebellar tonsils and vermis through foramen magnum with aqueduct stenosis and hydrocephalus
What is Dandy-Walker?
agenesis of cerebellar vermis with cystic enlargement of 4th ventricle (fills the enlarged posterior fossa)
What is syringomyelia?
cystic cavity within the spinal cord that usually crosses the anterior spinal commissural fibers first
What are the typical physical findings of syringomyelia?
“cape-like” bilateral loss of pain and temperature sensation in upper extremities (fine touch sensation is preserved)
What other malformation is syringomyelia associated with?
Chiari I malformation
What vertebral level is a lesion from syringomyelia typically located?
C8-T1
What is the treatment for syringomyelia?
monitoring and surgery
What branchial arches down the anterior ⅔ of the tongue develop from?
1st and 2nd branchial arches
What branchial arches down the posterior ⅓ of the tongue develop from?
3rd and 4th branchial arches
What is the motor innervation for the tongue?
CN XII
Where are the muscles of the tongue derived from?
occipital myotomes
What nerve supplies sensation to the anterior ⅔ of the tongue?
CN V3
What nerve supplies taste to the anterior ⅔ of the tongue?
CN VII
What nerve supplies sensation to the posterior ⅓ of the tongue?
CN IX and CN X
What nerve supplies taste to the posterior ⅓ of the tongue?
CN IX and CN X
