Embryology

Question 1

What does the notochord become?

Answer 1

nucleus pulposus

Question 2

What does the neural plate become?

Answer 2

neural tube and neural crest cells

Question 3

What do the neural crest cells become?

Answer 3

PNS neurons

Schwann cells

Question 4

What does the neuroectoderm become?

Answer 4

CNS neurons
ependymal cells
oligodendroglia
astrocytes

Question 5

What does the mesoderm become?

Answer 5

microglia

Question 6

What is the pathogenesis of spina bifida?

Answer 6

neuropores fail to fuse (4th wk) –> persistent connection b/t amniotic cavity and spinal canal

Question 7

What biomarkers will be seen before birth?

Answer 7

elevated alpha-fetoprotein in amniotic fluid and maternal serum

Question 8

What physical finding is associated with spina bifida occult?

Answer 8

tuft of hair or skin dimple at level of bony defect

Question 9

What is anencephaly?

Answer 9

malformation of anterior neural tube –> no forebrain, open calvarium

Question 10

What disease is anencephaly associated with?

Answer 10

maternal diabetes (type I)

Question 11

Maternal supplementation with folate decreases a baby’s risk of what diseases/conditions?

Answer 11

spina bifida

anencephaly

Question 12

What is holoprosencephaly?

Answer 12

failure of left and right hemispheres to separate

Question 13

What is the hypothesized pathogenesis of holoprosencephaly?

Answer 13

mutations in sonic hedgehog signaling pathway

Question 14

What is Chiari II (Arnold-Chiari malformation)?

Answer 14

significant herniation of cerebellar tonsils and vermis through foramen magnum with aqueduct stenosis and hydrocephalus

Question 15

What is Dandy-Walker?

Answer 15

agenesis of cerebellar vermis with cystic enlargement of 4th ventricle (fills the enlarged posterior fossa)

Question 16

What is syringomyelia?

Answer 16

cystic cavity within the spinal cord that usually crosses the anterior spinal commissural fibers first

Question 17

What are the typical physical findings of syringomyelia?

Answer 17

“cape-like” bilateral loss of pain and temperature sensation in upper extremities (fine touch sensation is preserved)

Question 18

What other malformation is syringomyelia associated with?

Answer 18

Chiari I malformation

Question 19

What vertebral level is a lesion from syringomyelia typically located?

Answer 19

C8-T1

Question 20

What is the treatment for syringomyelia?

Answer 20

monitoring and surgery

Question 21

What branchial arches down the anterior ⅔ of the tongue develop from?

Answer 21

1st and 2nd branchial arches

Question 22

What branchial arches down the posterior ⅓ of the tongue develop from?

Answer 22

3rd and 4th branchial arches

Question 23

What is the motor innervation for the tongue?

Answer 23

CN XII

Question 24

Where are the muscles of the tongue derived from?

Answer 24

occipital myotomes

Question 25

What nerve supplies sensation to the anterior ⅔ of the tongue?

Answer 25

CN V3

Question 26

What nerve supplies taste to the anterior ⅔ of the tongue?

Answer 26

CN VII

Question 27

What nerve supplies sensation to the posterior ⅓ of the tongue?

Answer 27

CN IX and CN X

Question 28

What nerve supplies taste to the posterior ⅓ of the tongue?

Answer 28

CN IX and CN X