CNS Embryology

Question 1

brain dev’t begins

Answer 1

3rd wk

Question 2

3 vescicles b/c 5 at..

Answer 2

5th wk

Question 3

Precursor of sensory neurons of spinal cord and DRG

Answer 3

Alar plate

Question 4

What separates the motor from sensory neurons in embryonal neural tube?

Answer 4

sulcus limitans

Question 5

Precursor of brainstem and the motor neurons in spinal cord

Answer 5

basal plate

Question 6

What separates the adult brainstem sensory neurons from the brainstem motor neurons?

Answer 6

Also the sulcus limitans

Question 7

Migration of spinal cord end

Answer 7

it goes caudally, from S1 @ 6m to L3 @9m to adult L1-2

Question 8

Failure of anterior neural pore to close

Answer 8

Anencephaly

Encephaloceole

Question 9

Failure of posterior neural pore to close

Answer 9

Myelomeningoceole
Spina bifida
Meningoceole

Question 10

Arnold Chiari Malformation

Answer 10

• Displacemnt of cerebellar tonsils below the foramen magnum
• type II is herniation with aqueductal stenosis and hydrocephalus
• type II pt has paralysis below defect and myelomeningoceole)

Question 11

What is derived from the neural crest?

Answer 11

• sensory neurons in the spinal cord ganglia
• CN V, VII, VIII, IX, X
• postganglionic ANS neurons
• Schwann cells
• adrenal medulla

Question 12

Primary vesicles (3)

Answer 12

• form at 4th week
• prosencephalon –> forebrain
• mesencephalon –> midbrain
• rhombencephalon –> hindbrain

Question 13

Secondary vesicles (5)

Answer 13

• form at 5th week
• telencephalon and diencephalon (both from prosencephalon)
• mesencephalon
• metencephalon and myencephalon (both from rhombencephalon)

Question 14

telencephalon

Answer 14

• forms from the prosencephalon

- gives rise to cerebral hemispheres

Question 15

diencephalon

Answer 15

• forms from prosencephalon

- gives rise to thalamus, hypothalamus, subthalamus

Question 16

metencephalon

Answer 16

• forms from rhombencephalon

- gives rise to pons and cerebellum

Question 17

myencephalon

Answer 17

• forms from rhombencephalon

- gives rise to medulla

Question 18

When does the anterior pore close?

Answer 18

day 25

Question 19

When does the posterior pore close?

Answer 19

day 27

Question 20

When do cerebral hemispheres enlarge?

Answer 20

8th week

Question 21

derived from neuroectoderm

Answer 21

CNS neurons,
ependymal cells,
oligodendroglia,
astrocytes

Question 22

derived from neural crest

Answer 22

PNS neurons,

Schwann cells

Question 23

derived from Mesoderm

Answer 23

Microglia