DEVELOPMENT OF CNS By Dr Samina Anjum NERVOUS SYSTEM    The central nervous system (CNS): - Brain and spinal cord The peripheral nervous system (PNS): - Neurons.

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Transcript DEVELOPMENT OF CNS By Dr Samina Anjum NERVOUS SYSTEM    The central nervous system (CNS): - Brain and spinal cord The peripheral nervous system (PNS): - Neurons.

Slide 1

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 2

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 3

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 4

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 5

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 6

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 7

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 8

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 9

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 10

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 11

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 12

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 13

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 14

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 15

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 16

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 17

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 18

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 19

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 20

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 21

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 22

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 23

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 24

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU


Slide 25

DEVELOPMENT OF CNS

By Dr Samina Anjum

NERVOUS SYSTEM





The central nervous system (CNS):
- Brain and spinal cord
The peripheral nervous system (PNS):
- Neurons outside the CNS
- Cranial and spinal nerves that connect the brain and
spinal cord with peripheral structures
The autonomic nervous system (ANS):
- Has parts in both the CNS and PNS.

Neurulation
CNS appears at the beginning of 3rd week of development.

Closure of Neural Tube
Day 25 Rostral
neuropore closes
 Day 28 Caudal
neuropore closes


Ectoderm to Neuroectoderm: 20 days
to 30 days

Rhombencephalic
isthmus

Pontine flexure

BRAIN FLEXURES
4th week





Rhombencephalic isthmus

Cephalic/Midbrain flexure
Cervical flexure
Pontine flexure
Flexures cause variation in outline
of T.S of brain at various levels &
in position of grey & white
substance

Pontine flexure

Development of Spinal Cord
Neuroepithelial, Mental and
Marginal layers

(White matter
Of S.C)
Neuroblasts (Gray matter of S.C)

Neuroepithelium
With Junctional
complexes at the
lumen

Basal, Alar, Roof & Floor plates

Histological Differentiation
Nerve cells, Glial cells & Neural crest cells
Vascular

Transient dendrite

Marginal layer
Lie b/w Blood vessels and neurons

SPINAL NERVES

Neural Crest Cells

NEURAL CREST CELLS

Myelination

Spinal cord begins in 4th month---1st year
Tracts in N.S myelinate when they start functioning
Neurilemmal sheath

PNS

CNS

Positional Changes in Spinal Cord

Subarachnoid space

3rd

month

End of 5th month

New born

Adult

Spina bifida occulta

Spina bifida cystica

Spina bifida

Meningomyelocele

Myeloschisis

Acrania, Cerebral regression &
Anencephaly

PITUITARY GLAND-ECTODERMAL

Rathke’s pouch

(Ectodermal out pocketing of stomodeum)
embryo is 3 weeks

End of 2nd month
Looses its connection with oral cavity

THANK YOU