Development of the Nervous System

Question 1

nervous system develops from what embryonic layer

Answer 1

ectoderm

Question 2

Neural tube gives rise to——

Brain in greek
Brain in latin

Answer 2

CNS (brain + spinal cord

Greek-encephalon
Latin-Cerebrum

Question 3

Notochord embryonic origin

Answer 3

mesodermal origin,

Question 4

Notochord development induces formation of

Answer 4

neural plate ( neural tube + neural crest)

Question 5

what is primary neuralation

Answer 5

the process by which d neural folds fuse
forming a neural
tube.

Question 6

derivatives of neural crest cells

Answer 6

● Pseudounipolar ganglion cells of the spinal and
cranial nerve ganglia
● Schwann cells (which elaborate the myelin sheath)
● Multipolar ganglion cells of autonomic ganglia.
● Leptomeninges (the pia-arachnoid), which envelop
the brain and spinal cord 5. Chromaffin cells of the
suprarenal medulla (which elaborate epinephrine).
● Pigment cells (melanocytes)
● Odontoblasts (which elaborate predentin)
● Aorticopulmonary septum of the heart
● Parafollicular cells (calcitonin-producing C-cells)
● Skeletal and connective tissue components of the
pharyngeal arches

Question 7

neural crest cell gives rise to the PNS which consists of

Answer 7

● Peripheral
nerves
● Sensory ganglia
● Autonomic
ganglia

Question 8

The alar plate of the brainstem & spinal cord gives rise to —– neurons

Answer 8

sensory neurons

Question 9

The basal plate of the brainstem & spinal cord gives rise to —– neurons

Answer 9

motor neurons

Question 10

protein in amniotic fluid which indicates neural tube defect

Answer 10

alpha-fetoprotein

Question 11

3 main vesicles from neural tube

Answer 11

Forebrain (prosencephalon)
Midbrain (mesencephalon)
Hindbrain (Rhombencephalon)

Question 12

cavity of Telencephalon
(cerebral hemispheres)

Answer 12

lateral ventricles

Question 13

5 vesicles

Answer 13

Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon

Question 14

cavity of diencephalon (thalamus + optic vesicle)

Answer 14

Third ventricle

Question 15

cavity of mesencephalon (Mid brain)

Answer 15

cerebral aqueduct

Question 16

cavity of metencephalon (pons and cerebellum)

Answer 16

upper 4th ventricle

Question 17

cavity of Myelencephalon (medulla)

Answer 17

Lower 4th ventricle

Question 18

3 layers of the spinal cord

Answer 18

inner - ventricular layer
intermediate -mantle layer
outer- marginal layer

Question 19

layer that forms the white matter
of the SC

Answer 19

marginal Layer

Question 20

layer that forms the gray matter
of the Spinal cord

Answer 20

mantle layer

Question 21

End of the spinal cord is

Answer 21

Conus medullaris
L3- Children
L1- Adult

Question 22

Part of the brain derived from dorsal surface of alar plate

Answer 22

Cerebellum

Question 23

Anterior neuropore gives rise to —–
Failure to close

Answer 23

Lamina terminalis
Anencephaly : partial or complete absence of the brain with associated
defects of the cranial vault and scalp.

Question 24

Failure of posterior neuropore to close

Answer 24

spina bifida (myeloschisis)

Question 25

Anterior neuropore closes by Day
Posterior neuropore close by Day
Period of primary gastrulation

Answer 25

25
27
18-28

Question 26

Type of spina bifida,
there is no involvement of the
meninges or the underlying spinal
cord, and the overlying skin is
closed.

Answer 26

Spina bifida occulta ( defect of mesodermal origin)

Question 27

Spina bifida aperta with protrusion
○ of either the meninges alone is ———
○ spinal cord together with the meninges Is ——-

Answer 27

Meningocele
Meningomyelocele

Question 28

Protrusion of a sac from the cranium consisting of portions of
the meninges and CSF, glial tissue, and brain substance with or without the ventricles due to failure of anterior neuropore to close is

Answer 28

Encephalocele
-could be frontal or occipital encephalocele

Question 29

HYdrocephalus
(excess accu. of CSF In subarachnoid space &ventricles) is commonly caused by stenosis of

Answer 29

Cerebral aqueduct

Question 30

Dandy walker syndrome is Congenital absence of the —– and ——which through lack of communication with the remainder of the ventricular system,
can be one cause of hydrocephalus.

Answer 30

lateral apertures (of Luschka)
median aperture (of Magendie),

Question 31

Clinical manifestations of Dandy walker syndrome

Answer 31

Dandy-Walker Syndrome:
● Dilated fourth ventricle,
● Water on the brain,
● Small vermis

Question 32

What is arnold-chiari malformation

Answer 32

elongation and herniation of the cerebellar tonsils though the foramen magnum thereby blocking CSF flow

Question 33

Failure of midline cleavage of embryonic forebrain

Answer 33

Holoprosencephaly

( most severe manifestation of fetal alcohol syndrome)

Question 34

Defect in the occipital bone through which meninges, cerebellar tissue, and 4th ventricle may herniate

Answer 34

Cranium bifidum

Question 35

Obstructive hydrocephalus is due to

Answer 35

• Dilated Lateral and III ventricles
• Constriction of the Cerebral Aqueduct

Question 36

abnormal closure of anterior neuropore affecting the
midbrain, hindbrain and entire spinal region dev.

Answer 36

craniorachischisis,

Question 37

Anencephaly with defects confined to the midbrain

Answer 37

meroanencephaly

Question 38

Anencephaly with lesions extending into the hindbrain

Answer 38

Holoanencephaly

Question 39

NTD teratogen
Signalling req. for closure

Answer 39

Retinoid

PCP Signalling