Development of CNS Flashcards
3 layers of the neural tube of the developing embryo
Endoderm, mesoderm, ectoderm
which is the inner layer of the neural tube of the developing embryo
Endoderm
which is the outer layer of the neural tube of the developing embryo
Ectoderm
How does the neuroepithelium form
Dorsal flexion of the ectoderm, and medial thickening of the ectoderm begins around 3 weeks
When does the neuroepithelium begin to form
begins around 3 weeks
Dorsal flexion of the ectoderm, and medial thickening of the ectoderm beginning around 3 weeks forms the …
neuroepithelium
the neuroepithelium is the …
wall of the neural tube
the wall of the neural tube is known as…
the neuroepithelium
Closure of the neural tube forms the …
neural canal
the neural canal forms on the closure of …
the neural tube
The neural crest develops lateral to the…
Neural canal
Lateral to the Neural canal you find …
the neural crest
The embryological basis of the dorsal root ganglion sensory neurons are the …
neural crest cells
The neural crest cells go on to form …
the dorsal root ganglion sensory neurons
NEUROBLASTS are …
Precursors to all neurons with cell bodies in the CNS
GLIOBLASTS are …
Precursors to astrocytes and oligodendrocytes (the glial cells)
EPENDYMAL CELLS purpose is to …
These line the ventricles and the central canal
What cell is: These line the ventricles and the central canal
EPENDYMAL CELLS
What cells are: Precursors to astrocytes and oligodendrocytes (the glial cells)
Glioblasts
What cell are: Precursors to all neurons with cell bodies in the CNS
neuroblasts
Origin of microglia?
microglia arise systemically and migrate to the brain after development
What cells arise systemically and migrate to the brain after development
Microglia
What cells do the neural crest differentiate into: (4)
Sensory neurons of the dorsal root ganglia
POSTGANGLIONIC AUTONOMIC NEURONS
SCHWANN CELLS – myelinating cells of the PNS
and Non-neuronal derivatives e.g. melanocytes
What cells do the neuroepithelium differentiate into (3)
Ependymal cells
Glioblasts
Neuroblasts
These cells originate from:
Ependymal cells
Glioblasts
Neuroblasts
neuroepithelium
These cells originate from:
Sensory neurons of the dorsal root ganglia
POSTGANGLIONIC AUTONOMIC NEURONS
SCHWANN CELLS – myelinating cells of the PNS
and Non-neuronal derivatives e.g. melanocytes
Neural crest cells
Neuroblasts are formed on the X layer but migrate Y
X - ependymal
Y - outward
Cell bodies of neurons form the X matter in the brain
Grey
Glial cells migrate to what type of matter (grey/white)
Both
Grey matter is mainly composed of …
Neuronal cell bodies
What type of glial cell is found in white matter mostly
Oligodendrocytes
5 different layers/sections of the neural tube?
Ependymal Dorsal Ventral Marginal Mantle
In the neural tube where is the ependymal layer? It’s function?
Innermost, where many neuronal cells originate
In the neural tube where is the marginal layer? It’s type of matter?
Marginal layer = white matter = outside
In the neural tube where is the mantle layer? It’s type of matter?
Mantle layer = grey matter (cell bodies) = middle, outer to the ependymal layer but inside the marginal layer
In the neural tube where is the roof plate?
Dorsally
In the neural tube where is the floor plate?
Ventrally
Ventral fibres are more [efferent/afferent]
Efferent
Dorsal fibres are more [efferent/afferent]
Afferent
Afferent fibres are found more commonly [ventrally/dorsally]
Dorsally
Efferent fibres are found more commonly [ventrally/dorsally]
Ventrally
Example of a signalling molecule that controls differentiation of neural cells? (think funny)
Sonic hedgehog
In the spinal cord, grey matter is on the [inside/outside]?
Inside
Dorsal neurons are in the what type of neurons in the developing spinal cord
Interneurons
Ventral neurons are in the what type of neurons in the developing spinal cord
Motor and interneuromns
What happens to the neural tube at the level of the brainstem
opens up It splits and becomes more lateral making the sensory neurons quite lateral
What happens to sensory neurons at the level of the brainstem in development
the neural tube (alar plate) opens up It splits and becomes more lateral making the sensory neurons quite lateral
In the brainstem lateral neurons are [afferent/efferent] [sensory/motor] neurons
Afferent sensory
In the brainstem medial neurons are [afferent/efferent] [sensory/motor] neurons
efferent motor
In the brainstem efferent motor neurons are [medial/lateral]
Medial
In the brainstem afferent sensory neurons are [medial/lateral]
Lateral
The Future forebrain is known as the …
Prosencephalon
The Future midbrain is known as the …
Mesencephalon
The Future hindbrain is known as the …
Rhombencephalon
the Mesencephalon becomes the …
midbrain
the Rhombencephalon becomes the …
hindbrain
the prosencephalon becomes the …
forebrain
The 3 main vesicles of the developing brain is visible by …
4 weeks
By 4 weeks in the developing brain you can see..
3 main vesicles
The diencephalon contains…
thalamus and hypothalamus
At 5 weeks the future brain develops
a division in the forebrain for the telencephalon and diencephalon
and division between the pons and medulla in the hindbrain
the telencephalon becomes …
the cerebral cortex
In the developing brain By 8 weeks you see…. (4)
- Developing hemispheres in the forebrain
- Appearance of the lateral ventricles and 3rd ventricle in the forebrain
- Aqueduct in the midbrain
- 4th ventricle in the hindbrain and developing cerebellum
The three flexures are known as:
Cephalic, pontine and cervical
From anterior to posterior the 3 flexures are
Cephalic, pontine and cervical
Difference between layers of grey and white matter in the spinal cord vs the brain?
grey matter inside on spinal cord, outside in the Brain
White matter outside in the spinal cord, inside in the brain
How many layers in the cerebral cortex?
6
What guides migration of neurons in the cortex
radial glial cells
How many layers of cells in the cerebellum
3
Production of the 6 layer cortex involves the migration of neurons out along radial glial cells from the X zone out to the Y zone to form the Z plate
X - ventricular
Y - marginal
Z - cortical
Production of the 6 layer cortex involves the migration of neurons out along radial glial cells from the X zone out to the Y zone to form the Z plate
X - ventricular
Y - marginal
Z - cortical
What is non-closure of the neural tube associated with
lack of folate
What is craniorachischisis
Completely open brain and spinal cord
What is anencephaly
Open brain and lack of skull vault
What is encephalocele
Herniation of the meninges (and brain)
What is spina bifida
Closed asymptomatic NTD in which some of the vertebrae are not completely closed
What is closed spinal dysraphism
Deficiency of at least two vertebral arches, here covered with a lipoma
What is meningocele
Protrusion of the meninges (filed with CSF) through a defect in the skull or spine
What is myelomeningocele
Open spinal cord with a meningeal cyst
What is iniencephaly
Occipital skull and spine defects with extreme retroflexion of the head
Open spinal cord with a meningeal cyst is known as….
myelomeningocele
Occipital skull and spine defects with extreme retroflexion of the head is known as….
iniencephaly
Protrusion of the meninges (filed with CSF) through a defect in the skull or spine is known as….
meningocele
Deficiency of at least two vertebral arches, here covered with a lipoma is known as….
closed spinal dysraphism
Closed asymptomatic NTD in which some of the vertebrae are not completely closed is known as….
spina bifida
Herniation of the meninges (and brain) is known as….
encephalocele
Open brain and lack of skull vault is known as….
anencephaly
Completely open brain and spinal cord is known as….
craniorachischisis
What nerves can sometimes regenerate and what can’t
peripheral sometimes, and CNS cannot
