Neurodevelopment (doherty) Flashcards
What happens in the 3rd week of neurodevelopment?
the ectoderm thickens and becomes the neural plate
what will the neural plate do?
fold to form the neural groove
what will the neural plate with the neural groove form?
the neural crest which will close forming a tube…the neural tube
identify the 2 orange lines
left: neural tube
right: notochord
what are the anterior and posterior neuropores?
at which week do the neuropores close?
openings in the neural tube that connect the tube with amniotic cavity
4th week
what will the anterior neuropore become?
lamina terminalis
identify the top and bottom lines
top: anterior neuropore
bottom: posterior neuropore
what is another name for the anterior neuropore?
what is another name for the posterior neuropore?
cranial
caudal
identify the blue and orange line
blue: pericardial bulge
orange: otic placodes
what will the placodes become?
Cranial Nerves 1 and 7
what will the olfactory placodes become?
what wil the otic placodes become?
they will become the olfactory nerve and bulbs
the organ of corti, spiral ganglion, cristae, maculae utriculi and sacculi, vestibular ganglion and CN 8
what are the cells of the neural tube?
what will each develop into?
- marginal layer (outer): develops into white matter
- mantle layer (intermediate): develops into grey matter (neurons and glia)
- neuroepithelial (inner): develops into the lining of the central canal of the spinal cord and ventricles
what is another name for neuroepithelial layer?
ependymal layer
where do we find alpha-feta protein?
if there are altered levels of alpha feta protein, what does this indicate?
what disease can be developed if alpha-feta protein is decreased?
in amniotic fluid
possible neural tube defect
down syndrome
what will the neural crest become?
- Dorsal root ganglia
- Spinal nerves
- Ganglia of cranial nerves
- Cranial nerves
- ANS ganglia
- Leptomeninges (Pia and arachnoid)
- Schwann cells
- Chromaffin cells (adrenal medulla)
- Pigment cells (melanocytes)
what is a disease that can result from problem with the neural crest cells, specifically the neurofibromin protein?
In this disease there is a problem with what? what will this result in?
neurofibromatosis
tumor suppression
neurofibromas, pigmented lesions (cafe au lait spots), pigmented iris hamartomas (lisch nodules)
what will the notochord become?
what is the function of the notochord before it becomes the other part? how does it do it?
the nucleus pulposus
helps in neurodevelopment of the motor neurons by producing sonic hedgehog protein
what happens at the end of the 4th week with the anterior portion of the neural tube?
it develops into 3 primary vesicles
what are the 3 primary vesicles that come from the anterior portion of the neural tube?
- Rhombencephalon (hindbrain)
- Mesencephalon (midbrain)
- Prosencephalon (forebrain)
what happens with the anterior portion of the neural tube at the end of the 5th week?
name the structures
the 3 primary vesicles will further develop
1) Prosencephalon: Telencephalon and Diencephalon
2) Mesencephalon: remains as Mesencephalon
3) Rhombencephalon: Metencephalon, Myelencephalon
what will the telencephalon become?
cerebral hemispheres
basal ganglia
lateral ventricles
olfactory bulbs
what will the diencephalon become?
epithalamus
hypothalamus
thalamus
pineal gland
3rd ventricle
optic nerve
optic chiasm
what will the mesencephalon become?
midbrain
cerebral aqueduct
what will the metencephalon give rise to?
pons
cerebellum
upper part of the 4th ventricle
To what structures will the myelencephalon give rise to?
medulla
lower part of 4th ventricle
what are commissures?
which commissure develops first? second? third?
bundles of axons that connect one hemisphere with the other
1- anterior commissure
2- hippocampal commissure
3- corpus callosum
what is the order of neurodevelopment in weeks?
week 0 = conception
week 3 = neural plate develops
week 4 = neural plate completely developed
week 4/5 = development of 1ry vesicles
week 6 = development of telencephalon from 1ry vesicles
weeks 12-22 = development of corpus callosum
4th month = myelination begins
4th-8th month = development of sulci and gyri
Alar and Basal plates are present from where to where in the Nervous System?
what cells make up the alar and basal plates?
from midbrain to spinal cord
neuroblasts
what will neuroblast cells of the alar plate in the spinal cord become?
waht will neuroblast cells of the basal plate in the spinal cord become?
what will neuroblast cells of the alar plate in the brainstem become?
what will neuroblast cells of the basal plate in the brainstem become?
the dorsal horn
the anterior horn
afferent or sensory component of cranial nerves
efferent or motor component of cranial nerves
what separates the alar and basal plates from the midbrain through the spinal cord?
sulcus limitans
what kind of information enters the dorsal horns?
waht kind of infromation enters the anterior horns?
what type of neural matter (grey or white) will the ventral and dorsal horn be?
sensory information from dermatomes
motor information
grey mater both
most cranial nerves can be found where?
midbrain and medulla
what does the cerebellum do?
what side of the body will each hemisphere of the cerebellum control?
what will the cerebellar vermis controll?
balance and coordination by both hemispheres
left hemisphere controls left leg and arm
right hemisphere controls right leg and arm
vermis = trunk
what helps the cortex neurons reach their destination during development? from where to where do these go?
what happens when cortex neurons have to climb to far places in the cortex?
climbing using radial glial cells
from inside to outside
it increases the posibility of errors –could explain schizophrenia
from where does the anterior pituitary come from?
from where does the retina come from?
neurons that have soma outside the CNS come from where?
all neurons that have soma inside the CNS come from where?
what moves the CSF?
from oral ectoderm or Rathke’s pouch
the diencephalon
neural crest
neural tube
cilia from ependymal cells
what is the APGAR scale?
scale used to evaluate a newborn’s cardio and neurological functions
give the name for what the score should be for the APGAR scale
what is considered a good APGAR scale?
what is a normal score?
what is a low score?
9-10
7
0-3
what is this?
periventricular leukomalacia
what is periventricular leukomalacia?
is it more frequent unilateral or bilateral?
what can it result in?
it is a potential cause of what?
a white matter infarct that happens during a episode of hypotension in premature infants
bilateral
diplegia or quadriplegia
cerebral palsy
what type of spina bifida is this?
what is spina bifida occulta?
defect in the vertenral arch
asymptomatic
look for a small patch of hair
what are the spina bifida cystica types?
1) spina bifida cystica with meningocele
2) spina bifida cystica with meningomyelocele
3) spina bifida cystica with myelocele
4) spina bifida cystica with syringomyeloce
what is spina bifida cystica with meningocele?
what is spina bifida cystica with meningmyelocele?
what is spina bifida cystica with myelocele?
what is spina bifida cystica with syringomyelocele?
only the meninges projects outside
the meninges and the spinal cord herniate outside
open neural tube lies in the surface of the back
meningomyelocele witha huge central canal
what is anancephaly?
why does it happen?
how soon can it be detected in utero?
how?
abscense of skull and cerebral hemispheres
lack of closure of anterior neuropore
14 weeks
elevated AFP
what is this?
anancephaly
what is this type of spina bifida cystica?
what is this type of spina bifida cystica?
spina bifida cystica with meningomyelocele
what is this type of spina bifida cystica?
what is this type of spina bifida cystica?
syringomyelocele
what is anancephaly with raschischisis?
anancephaly with non closure of the posterior en of the neural tube
what is this?
holoprosencephaly
what is holoprosencephaly?
when there is fusion of midline structures
Ex: ventricle (1 large), eyes (cyclopia)
what is porencephaly?
when there is an infarct and a cyst forms
what is this?
porencephaly
what is lissencephaly?
brain with no gyri
what is tuberous sclerosis?
what are 2 symptoms that can be found early in life?
when there is no difference between gray and white matter, resulting in large white gyri
retardation and seizures
what is another name for tuberous sclerosis?
bournville’s disease
what is this?
tuberous sclerosis (bourneville)
what is the most common cause of hydrocephaly?
fetal viral infection with toxoplasmosis gandii or CMV
what is hydrocephaly?
when there is excess CSF enlargin the skull
what is hydrancephaly?
how do you check for this?
disease where the cerebral hemispheres are absent and replaced with large cysts with CSF
if flashlite is used against skull, skull will appear transilluminated (light will pass through skull without problem)
what is Arnorld Chiary syndrome type 1 ?
asymptomatic, herniated tonsil of cerebellum less than 3 mm below foramen magnum
what is Arnorld Chiary syndrome type 2?
tonsilar cerebellar herniation with cerbellar vermins included
what is Arnorld Chiary syndrome type 3?
Herniation of brainstem and cerebellum outside
of skull. (a encephalocele)
what is arnorld chiari type 4?
Herniation of brainstem outside of skull with lack of development of cerebellum
what is this?
arnorld chiari type 4
what is dandy walker syndrome?
very large dilation of 4th ventricle with no vermis in cerebellum
what is agenesis of the corpus callosum?
so …why does this happen?
at what stages does the problem start?
ppl born without a corpus callosum
axons that should cross..dont..and form probst bundles on same side of brain
3rd-12th week of gestation
what is this?
agenesis of corpus callosum
what is a coloboma?
to where can it extend to?
Congenital defect resulting in a fissure of part of
the eye, most often the iris, usually inferior/nasal
(Coloboma Iridis)
to the ciliary body
what will a coloboma of the retina impair?
what will a coloboma iridis impari?
vision
nothing
what is complete Heterochromia Iridum?
what is partial Heterochromia Iridum?
what may cause heterochromia iridium if the affected iris is lighter?
what may cause heterochromia iridium if the affected iris is darker?
- one iris different color from the other.
- part of one iris a different color.
- Simple’ heterochromia, no ocular/visual problems.
Horner’s and Hirschsprung’s disease.
- Lisch nodules (harmartomas of the iris, in NF 1).
Sturge-Weber syndrome.
