neuro

Question 1

what causes differentiation of ectoderm –> neuroectoderm?

Answer 1

notochord (mesoderm)

Question 2

what does the neural plate –> ?

Answer 2

neural tube

neural crest cells

Question 3

alar vs basal plate?

Answer 3

alar = dorsal = sensory
basal = ventral = motor

Question 4

primary vesicles of brain?

Answer 4

forebrain = prosencephalon
midbrain = mesencephalon
hindbrain = rhombencephalon

Question 5

secondary vesicles of brain?

Answer 5

forebrain –> telencephalon, diencephalon
midbrain –> mesencephalon
hindbrain –> metencephalon, myelencephalon

Question 6

derivatives of telencephalon?

Answer 6

cerebral hemispheres

lateral ventricles

Question 7

derivatives of diencephalon?

Answer 7

thalamus

third ventricle

Question 8

derivatives of mesencephalon?

Answer 8

midbrain

aqueduct

Question 9

derivatives of metencephalon?

Answer 9

pons
cerebellum
upper part of fourth ventricle

Question 10

derivatives of myelencephalon?

Answer 10

medulla

lower part of fourth ventricle

Question 11

derivatives of neuroectoderm?

Answer 11

CNS neurons
ependymal cells
oligodendroglia
astrocytes

Question 12

derivatives of neural crest?

Answer 12

PNS

Schwann cells

Question 13

neurological derivatives of mesoderm?

Answer 13

microglia

notochord –> nucleus pulposus

Question 14

when should the neuropores of the NT fuse?

Answer 14

4th week

Question 15

NT defects - cause, dx?

Answer 15

cause: low folic acid intake
dx: increased AFP (amniotic fluid and maternal serum); increased AChE in amniotic fluid

Question 16

no forebrain, open calvarium, assoc with maternal T1DM?

Answer 16

anencephaly
increased AFP, polyhydramnios (no swallowing)
** give folate to decrease risk

Question 17

range of presentations from cleft lip/palate –> cyclopia?

Answer 17

holoprosencephaly
failure of L/R hemispheres to separate - weeks 5-6
related to SHH mutations
Patau, fetal alcohol

Question 18

herniation of cerebellar tonsils and vermis through foramen magnum?

Answer 18

Chiari II malformation
get aqueductal stenosis and hydrocephalus
often presents with lumbosacral emningomyelocele, paralysis below defect

Question 19

agenesis of cerebellar vermis, enlarged 4th ventricle?

Answer 19

Dandy-Walker malformation

associated with hydrocephalus, spina bifida

Question 20

capelike B/L loss of pain and temperature, fine touch preserved?

Answer 20

syringomyelia
most common C8-T1
assoc with Chiari malformations, trauma, tumors

Question 21

cerebellar tonsillar ectopia >3-5 mm, H/A, cerebellar symptoms?

Answer 21

Chiari II malformation
congenital
usually asx in childhood

Question 22

which branchial arches contribute to the anterior 2/3 of the tongue?

Answer 22

1 and 2

–> sensation = CN V3, taste = CN VII

Question 23

which branchial arches contribute to the posterior 1/3 of the tongue?

Answer 23

3 and 4

–> sensation and taste CN IX; far posterior = CN X

Question 24

motor innervation of tongue?

Answer 24

CN XII –> hyoglossus, genioglossus, styloglossus

CN X –> palatoglossus