Neuro development

Question 1

meningocele

Answer 1

sac with only meninges and CSF

Question 2

Meningoencephalocele

Answer 2

sac with meninges + brain tissue

Question 3

Meningohydroencephalocele

Answer 3

**most severe, meninges + brain tissue + part of lateral ventricle

Question 4

By the ___ week of development, the dorsal midline ectoderm thickens to form the neural plate

Answer 4

3rd

Question 5

The nervous system develops from week ___ to ___?

Answer 5

2 to 16

Question 6

Blastomere =?

Answer 6

cells from first mitotic division, after the fertilized egg

Question 7

What is the next step in development after the blastomere?

Answer 7

The morula (12-16 cells)

Question 8

When does the morula start to migrate/ form inner and outer cell mass?

Answer 8

Day 5

Question 9

When a cavity forms in the morula, it is called?

Answer 9

blastocyst

Question 10

The “inner” cell mass becomes?

Answer 10

The embryo, sometimes called “embryoblasts”

Question 11

What does the “outer” mass become?

Answer 11

becomes the placenta, the cells are called “trophoblasts”

Question 12

What are the two types of trophoblasts?

Answer 12

“synchiotrophoblasts” which go deeper into the uterine wall and “cytotrophoblasts” which cover the embryo and stick out into the uterine cavity.

Question 13

Which is last to develop, ecto, endo or mesoderm?

Answer 13

Mesoderm

Question 14

What does the “ectoderm” form?

Answer 14

sensory organs, epidermis, nervous system

Question 15

What does the “mesoderm” form?

Answer 15

Dermis, muscles, skeleton, urogenital systems, circulatory system

Question 16

What does the “endoderm” form?

Answer 16

GI system, Liver, Pancreas, Respiratory system

Question 17

When does “neurulation” happen? (at which stage)

Answer 17

In the Embryonic stage (2-8 weeks)

Question 18

Define primary and secondary neurulation

Answer 18

Primary: infolding of neural plate, Secondary: sacral and coccygeal formation

Question 19

Somites and the Notochord come from which embryonic layer?

Answer 19

Mesoderm

Question 20

When does the superior neuropore close?

Answer 20

Day 27

Question 21

When does the inferior neuropore close?

Answer 21

Day 30

Question 22

The marginal layer of the ectoderm becomes the?

Answer 22

White matter

Question 23

The mantle layer of the ectoderm becomes the?

Answer 23

Grey matter

Question 24

What represents dermatomal development of a fetus?

Answer 24

Somites

Question 25

What cells eventually make up the peripheral nervous system?

Answer 25

Neural crest cells

Question 26

Immature astrocytes are ? What is their function?

Answer 26

Radial glial cells, they direct the neuroblasts to the proper area of the brain by releasing cytokines

Question 27

Function of the notochord?

Answer 27

Defines long axis, orients vertebrae, eventually becomes the nucleus pulposus of the vertebral bodies

Question 28

What is the origin of the dorsal horn?

Answer 28

The alar plate

Question 29

What is the origin of the ventral horn?

Answer 29

The basal plate

Question 30

What are the 3 regions formed from the somites?

Answer 30

Dermatome (becomes dermis/sensory), Sclerotome (bone development) and myotome (muscle dev.)

Question 31

What do the neural crest cells produce?

Answer 31

posterior root ganglia, sensory:CN, autonomic ganglia, adrenal medulla, melanocytes, pancreatic islets

Question 32

What is 'Colchicine'?

Answer 32

A medication used for Gout (it increases uric acid secretion in the kidneys) but it blocks microtubules (therefore blocking neurological development) so it SHOULD NOT be given to women of child-bearing age.

Question 33

When does myelination begin? When is it finished?

Answer 33

Begins: in 4th month of gestation Ends: by age 3

Question 34

Corticospinal tracts are myelinated by what age?

Answer 34

2 years

Question 35

Cortical assoc. fibers are myelinated by what age?

Answer 35

3 years

Question 36

What is "polyneuronal development"?

Answer 36

Embryonically we have a lot more cells than we actually need, polyneuronal development is referring to the cell maturation process and how >50% wil die in this process

Question 37

When will polyneuronal development//maturation be complete?

Answer 37

By week 25

Question 38

When a fetus is born with cyclopia or other severe facial deficits, what could they have?

Answer 38

Holoprosencephaly

Question 39

What does "lissencephaly" mean?

Answer 39

term used when no gyri are present

Question 40

Possible causes of Holoprosencephaly?

Answer 40

Sporadic, maternal DM, or underlying chromosomal abnormalities such as trisomy 13.

Question 41

Explain what Arnold Chiari is

Answer 41

when the inferior cerebellum and medulla protrude through the foramen magnum

Question 42

What are the possible manifestations of Arnold Chiari?

Answer 42

Asymptomatic, CN deficits (usually lower), cerebellar deficits, hydrocephalus, and migraine headaches

Question 43

Is spina bifida occulta assoc. with folic acid deficiency?

Answer 43

NO!

Question 44

Spina Bifida-meningocele usually results in? Is it corrected surgically?

Answer 44

usually no deficits, yes surgically corrected

Question 45

What is spina bifida occulta due to?

Answer 45

failure of the dorsal vertebrae to close

Question 46

Does spina bifida meningomyelocele result in deficits?

Answer 46

Yes, always

Question 47

What is called when there is spina bifida and part of the cord is outside the body with no overlying skin?

Answer 47

Myeloschisis

Question 48

Meningocele = ?

Answer 48

sac with only meninges and CSF

Question 49

Meningoencephalocele = ?

Answer 49

meninges + brain tissue

Question 50

Meningohydroencephalocele = ?

Answer 50

most severe, meninges + brain tissue + part of lateral ventricle