Neurological System Development

the ______________ becomes the CNS, PNS, and outer epidermis of the skin

ectoderm

the ______________ becomes dermatomes, myotomes, and sclerotomes

mesoderm

the __________________ becomes the gut

endoderm

the neural __________ becomes the CNS (brain and spinal cord)

tube

the neural _____________ becomes the PNS (cranial, spinal, and autonomic ganglia and nerves)

crest

What does the notochord become?

vertebral body

the neuroplate, containing a neural groove and neural folds, develops at _____ days of gestation

18

At what day is the first menstrual period missed?

15

the end of the neural tube close, and the walls become thickened to develop the brain and spinal cord at _____-_____ days of gestation

24-26

the hole down the center of the neural tube becomes the _____________ system of the brain and the ________________ for the spinal cord

ventricular; central canal

a birth defect occurring when the neural tube does not close at the top, and the brain is absent

anencephaly

a birth defect occurring when the neural tube does not close in the center

spina bifida (myelodysplasia)

At what days is there a risk severe brain and spinal cord anomalies such as anencephaly and myelodysplasia?

24-26 (closure of the neural tube)

________________ are groups of mesoderm that will give rise to cells that will eventually form the vertebrae and ribs

somites

True or False: Muscle masses will trail their nerves with them as they differentiate into the limbs.

true

at _____ weeks, the fetus looks human and has completed the most critical period of CNS development

8

at ____ weeks, the neural folds fuse to form three primary brain vesicles

4

at ____ weeks, the primary vesicles divide into five secondary vesicles

5

What are the three primary brain vesicles?

forebrain, midbrain, and hindbrain

the forebrain divides into the ________________ and _______________

telencephalon and diencephalon

the midbrain becomes the _______________

mesencephalon

the hindbrain divides into the _______________ and ______________

metencephalon and myelencephalon

What are the five secondary vesicles?

telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon

the telencephalon forms the ______________

cerebral hemispheres

the diencephalon forms the _____________

thalamus

the mesencephalon forms the _____________

midbrain (cerebral peduncles and tectum)

the metencephalon forms the ______ and ______________

pons and cerebellum

the myelencephalon forms the _______________

medulla oblongota

4th week of gestation:

- the embryo is _______ cm

- is the brain developed?

- you can see which vesicles?

- made up mostly of ______ and the spinal cord

0.6; no; primary; eye

5th week gestation:

- the embryo is _____ cm

- you can see which vesicles?

- the eye is much smaller

1.7; secondary

3 months or 12 weeks gestation:

- the embryo is ______ cm

- you can now see the cerebral hemispheres, thalamus, and midbrain

7.8 (3 in)

the major structures of the brain are present at _______ weeks of gestation

24

What limits survival at 24 weeks of gestation?

cardiopulmonary system (and immature brain)

the fetal brain is highly susceptible to __________ which can occur from relatively mild stresses to the infant's system

anoxia

decreased oxygen to the brain

hypoxemia

decreased perfusion to the brain

ischemia

lack of oxygen without pulse

asphyxia

asphyxia occurs due to a drop in _______________

BP

Name the lobe:

- responsible for memory, personality, and motor control

- contains the primary motor cortex

- damage to this lobe will result in paralysis and spasticity

frontal

Name the lobe:

- responsible for integrating senses

- damage to this lobe will result in sensory processing disorders

parietal

Name the lobe:

- responsible for vision

occipital

Name the lobe:

- responsible for memory, hearing, and speech on the L side

temporal

Name the brain structure:

- located around the thalamus

- important for movement initiation and coordination

- damage to this structure will result in hyperkinesia (athetosis), hypokinesia (bradykinesia and dyskinesia), rigidity, and a resting tremor

basal ganglia

Name the brain structure:

- responsible for posture and motor planning

- damage to this structure will result in dysmetria, dysdiadochokinesia, hypotonia, ataxia, and intention tremors

cerebellum

neural ___________ is the ability of the nervous system to change

plasticity

plasticity is the greatest when the nervous system is _______________

developing

_______________ includes the ability of damages neurons or nerve tracts to adapt

plasticity

Activity dependent changes in neural circuitry usually occur during a restricted time in development. What are these restricted times called?

critical periods

adaptability was thought to be limited to _______________ because regeneration could not occur

reorganization

True or False: New neurons can be produced in the damaged area following a stroke.

true

Name the recovery phenomenon:

- damages axons can give off new processes which lead to synapses forming

- PT attempts to use this reorganization for the recovery of function

collateral sprouting

Can the PNS regenerate?

yes (1 inch/month)

anything that causes malformation in an embryo; examples include viruses, drugs, stress, and malnutrition

teratogen

When is the embryo not susceptible to teratogens?

first two weeks of gestation

if a teratogen is introduced in 3-6 weeks of gestation, the embryo is susceptible to ____________ deficiencies

limb

if a teratogen is introduced in 3-20 weeks of gestation, the embryo is susceptible to _______ issues

CNS

if a teratogen is introduced in 3-4 weeks of gestation, the embryo is susceptible to __________________________

myelomeningocele

if a teratogen is introduced in 5-6 weeks of gestation, the embryo is susceptible to agenesis of the ___________________

corpus callosum

if a teratogen is introduced in 8-16 weeks of gestation, the embryo is susceptible to _______________

microcephaly

if a teratogen is introduced in 16-20 weeks of gestation, the embryo is susceptible to _____________, meaning there are holes in the brain

schizencephaly

if a teratogen is introduced in 7-8 weeks of gestation, the embryo is susceptible to developing a ________________

cleft palate

Some body structures grow together. What often grows the same time as the palate?

ear

in embryo, the spinal nerves pass through the intervertebral foramina (above / at the level of / below) its origin

at the level of

What tissue grows the fastest?

bone

At 8 weeks gestation, the caudal end of the spinal cord lies where?

tip of the sacrum

At 6 months gestation, the caudal end of the spinal cord lies where?

S1

As a newborn, the caudal end of the spinal cord lies where?

L3

As an adult, the caudal end of the spinal cord lies where?

L1

dorsal and ventral roots below the caudal end of the spinal cord are called the _____________

cauda equina

myelinization starts after neuron formation around ____-____ weeks of gestation

12-20

myelinization first occurs in the _____________ and ______________ for swallowing and sucking

medulla and cranial nerves

What system is myelinated by the end of the 5th month?

vestibular

_______________ must be transported through the blood-brain barrier to bring nutrition to the brain because no fats exist in the brain

lipids

it is important to drink breast, whole, or 2% milk through the age of _____

2

Which milk is not beneficial for babies to drink in the first two years of life?

A. breast milk

B. skim milk

C. 2% milk

D. whole milk

B

fetal movements begin in utero at about ____-____ weeks gestation

6-7

_________ movements in response to touch have been reported as early as 7-8 weeks

reflex

reflex connections, like development, progress in a ________________ direction (arm withdrawal before leg withdrawal)

cephalocaudal (top down and proximal to distal)

the first _____ months after birth are considered a period of CNS organization

2

synaptic proliferation occurs from birth to _____ years of age

4

What are two critical periods of brain growth (in months)?

3-10 and 15-24

_____________________ during the critical periods of development is shown to cause impaired motor ability

malnourishment

brain weight doubles by ______ months

6

fibers in the brain are largely (myelinated/unmyelinated) at birth

unmyelinated (continues into young adulthood)

myelination of the (CNS/PNS) is largely complete at birth

PNS

True or False: At birth, the PNS allows immediate access to information about the environment through touch, motion, smell, and taste.

true

Are cranial nerves myelinated at birth?

yes

during the first 6 months, an infant will demonstrate a positive ________________ sign

Babinski

recall of events is minimal until the child is about _____ years of age

3

What is the leading known cause for microcephaly (MR)?

fetal alcohol syndrome (FAS)

What is the most common physical disability in childhood?

cerebral palsy (CP)

Guidelines for Pediatric Treatment:

1. practice, practice, practice

2. make practice _____ and motivating

3. thoughtfully _______ and practice activities

4. use _____ to promote desired functional outcomes

5. adjust task complexity and ______________

6. schedule practice to enhance retention and transfer

7. adapt the physical _______________ to support desired motor behaviors

8. conduct practice in the ___________ environment

9. consider the influence of the psychosocial environment

10. thoughtfully provide _________________ information

(type number followed by answer)

2. fun

3. plan

4. toys

5. difficulty

7. environment

8. natural

10. augmented

Which artery of the brain will affect the face and upper extremity?

middle cerebral

Which artery of the brain will affect the lower extremity?

anterior cerebral

describe Homunculus starting from the lateral ventricle and working to the outside

foot, hip, trunk, arm, hand, face, tongue, larynx

According to Homunculus, which body part is situated at the primary motor cortex (MI)?

arm

Where do the corticospinal tracts cross?

medulla

a softening of the white brain matter near the ventricles due to decreased perfusion of the corticospinal tracts in this area

PVL

corticospinal spinal tracts are also called ________________ tracts because they cross in the medulla and form a triangle

pyramidal

Where do the corticospinal tracts come from?

primary motor cortex