Test 2: Neruological System Development

CNS arises from

ectoderm

Ntochord turns into

vertebral body

Neural tube turns into

CNS

The neural crest turns into

PNS

Neuroplate develops containing a neural groove and neural folds occurs by

18 days

The ends of the tube close and the walls become thickened to develop the brain and spinal cord occurs by

24-26 days

The hole down the center because the

ventricular system of the brain and the central canal of the SC

Somites

mesoderm (myotomes, sclerotome, and dermatome)

At ______ weeks the baby look human and has completed the most critical period of the CNS development

8 weeks

What week do neural folds fuse to form 3 pirmary brain vesicles

4th weeks

What week does the primary vesicles divide into 5 secondary vesicles

5th week

CNS proliferates and differentiates and fold upon each other to form the

cortical lobes and brainstem

What are the 3 primary vesicles

forebrain, midbrain, hindbrain

forebrain turns into

telencephalon and diencephalaon

Midbrain turns into

mesencephalon

Hinbrain turns into

Metencephalon

myelencephalon

telecephalon turns into

cerebral hemispheres

diencephalon turns into

thalmus

Mesencephalon turns into

midbrain

Metencephalon turns into

pons nd cerebelluma

The myelencephalon turns into

medulla oblongata

When are the major structures of the brain are present

24 weeks

What is the problem at 24 weeks?

The cardiopulm system and the immature brain, fetal brain is highly susceptible to anoxia which can occur from relative mild stresses to the brain

Hypoxemia

decrease O2 to the brain

Ischemia

decrease perfusion to brain

asphyxia is

lack of O2 without pulse (decrease in BP in children)

ability of the nervous to change is

plasticity

Critical peroid

activiy dependent chagnes in neural circuitry usually occue during a restricted time in development, the brain is particularly sensitive to the effect of experience

3-4 weeks what is the baby at risk for

myelo (spina bifida)

5-6 weeks baby is at risk for

agenesis of corpus callosum

9-16 weeks baby is at risk for

microcephaly

16-20 weeks baby is at risk for

skiz encephaly

vertebral column and udra matter grow more rapidly

than the spinal cord, so this relationship cahgnes

SC ends 8 weeks gestation

caudal end lies at tip of sacruj

SC ends 6 months gestation

caudal end lies at S1

Newborn SC ends

L3

adult SC ends

L1

Myslinization starts after neuron formation around

12-20 weeks gestation

What is first thing to be myelinized

medulla and cranial nerves for swallowing and sucking

Vestibular system is myelinated

by the end of the 5th month

fetal movements begin in utero at about

6-7 weeks gestation

felex movements in reponse to touch have been reposrted at early at

7-8 weeks

the first two months after birth are considered a peroid of

CNS organization

Critical peroids of brain growth

3-10 months, 15-24 months, synaptic proliferation from birth to 4 years

Positive babinski sign occurs

for first 6 mongths