CNS Embryology

Question 1

When is the embryonic period

Answer 1

Conception to week 8

Question 2

When is the Fetal Period

Answer 2

Week 8 to Birth

Question 3

When is the Neonatal Period

Answer 3

After birth

Question 4

Where does the neural plate develop from ( which layer )

Answer 4

Embryonic ectoderm

Question 5

Inner Cell Mass is converted into

Answer 5

Trilaminar embryonic disc

4 extra embryonic membrane

Question 6

Fetus will develop from the ?

Answer 6

Embryonic Disc

Question 7

What are the layers of the embryonic disc ( from outer to inner )

Answer 7

Ectoderm
Mesoderm
Endoderm

Question 8

What does the ectoderm differentiate into ( 5 )

Answer 8

Epidermis of skin 
Nervous Tissue 
Pituitary Gland 
Adrenal Medulla 
Teeth and Lens

Question 9

What does the mesoderm differentiate into ( 8 )

Answer 9

Epithelial lining of blood vessels
Dermis of Skin 
Muscle Tissue 
Connective Tissue 
Heart 
Kidney and Ureters 
Adrenal Cortex
Spleen 
Internal Reproductive Organs

Question 10

What does the endoderm differentiate into ( 8 )

Answer 10

Epithelial lining of resp and GI 
Liver
Gallbladder 
Pancreas 
Thymus 
Thyroid 
Parathyroid 
Palatine Tonsils

Question 11

What happens during gastrulation ( what is formed )

Answer 11

Formation of primitive streak

Formation of notochord

Question 12

What kind of cells form the notochord

Answer 12

Mesodermal Cells

Question 13

What makes the neural plate

Answer 13

A thickened layer of the endoderm

Question 14

Once the notochord induces the specialisation of neural plate, what do you get

Answer 14

Neural Groove

Question 15

After the neural plates develops the longitudinal neural groove, what do you get on each side

Answer 15

Neural Folds

Question 16

Where does the neural folds fuse and what does it form

Answer 16

It fuses in the median plane and will form neural tube. After that, neural tube will separate from surface ectoderm.

Question 17

When neural tube separates from the ectoderm, what structure is formed?

Answer 17

Neural crest

Question 18

What does the neural crest form ( 3 )

Answer 18

Dorsal Root Ganglia
Autonomic Ganglia
Pia / Arachnoid Mater

Question 19

When does neurulation end

Answer 19

By week 4

Question 20

Where are neuropores formed on the neural tube

Answer 20

Rostral and caudal part of the neural tube

Question 21

When the neural plate expands rostrally, what structure develops from it

Answer 21

The brain

Question 22

When the neural tube separates from the surface ectoderm what is formed

Answer 22

Neural Crest

Question 23

What develops from the neural crest

Answer 23

Dorsal Root Ganglia
Autonomic Ganglia
Pia and Arachnoid Mater

Question 24

When the rostral neuropore closes, the thickened neural folds fuse to form 3 primary brain vesicles

Answer 24

Forebrain ( Prosencephalon )
Midbrain ( Mesencephalon )
Hindbrain ( Rhombencephalon )

Question 25

The myelencephalon will form ( ) | The mesencephalon will form ( )

Answer 25

Medulla Oblongata | Pons and Cerebellum

Question 26

Between what weeks does the brain tube fold and at how many points?

Answer 26

Week 4 - 8 | 3 points

Question 27

Forebrain folds at the ( )

Answer 27

Mesencephalic ( cranial / cephalic ) flexure

Question 28

Ventral folding occurs at ( ) between ( )

Answer 28

Cervical flexure between the myelencephalon and spinal cord

Question 29

Reverse dorsal flexion at

Answer 29

Pontine flexure

Question 30

The development of spinal cord is due to the proliferation of

Answer 30

Ventricular layer of neuroepithelial cell

Question 31

Where do neuroblasts migrate to and where does it extend its cell processes to

Answer 31

Migrates to mantle layer ( grey matter ) and will extend cell processes to marginal layer ( white matter )

Question 32

What is the Mantle Layer? | What is the Marginal Layer

Answer 32

Mantle : Grey Matter | Marginal : White

Question 33

In the development of brainstem, the mantle zone is organised into ( ) like in spinal cord

Answer 33

Alar and basal plate

Question 34

The cerebellum arises from ( ) of the ( )

Answer 34

Dorsal rhombic lips of alar plates

Question 35

How does the cerebrum develop via proliferation, migration and differentiation ?

Answer 35

Proliferating cells in the ventricular zone will produce waves of neuroblasts Neurons will migrate outwards to establish cortical layers

Question 36

What are the two causes of disorders of neuronal migration ?

Answer 36

Defects in lamination of 6 layered structure | Failed formation of gyri and sulk

Question 37

What are mini columns and do patients with autism have increased or decreased packing

Answer 37

``` Vertical assemblies of neurons Increased packing ( Layer III has less space ) ```