Brain development Flashcards
Development
Following fertilisation what forms?
Morula (16 cells)
Blastocyst (16+ cells)
What structure is 16 cells in development?
Morula
What structure forms after morula (16+ cells)
Blastocyst
What forms after blastocyst?
Tri-laminar disc forms
What are trilaminar discs?
Ectoderm
Mesoderm
Endoderm
What forms neural plate?
Ectoderm
When does ectoderm form neural plate?
3rd week
How does neural tube form?
Neural plate undergoes mitosis
Neural groove formed
Groove deepens and detaches
Form neural tube
What do neural crest cells form?
Sensory ganglia
Schwann cells
Adrenal medulla
Meninges
Dermis
What cells form meninges?
Neural crest cells
What forms in week 5?
Prosencephalon
Mesencephalon
Rhombencephalon
What occurs in week 7?
Secondary brain vesicles develop
Give rise mature brain
Process brain formation
1) Fertilisation
2) Morula (16 cells)
3) Blastocyst (16+)
4) Trilaminar disc- ecto, meso, endo derm
5) Third week ectoderm thickens
6) Neural plate formed
7) Mitosis of neural plate
8) Form neural groove
9) Groove deepens
10) Forms neural tube
11) Neural crest cells
12) Week 5- prosencephalon, mesencephalon and rhombencephalon
13) Week 7- secondary brain vesicles
14) Mature brain
What occurs at 3 weeks?
Eye formation
When are basic structures brain developed?
3 mnths
When does myelination begin?
25 weeks
When do gyri and sulci form?
9 months
When does lobes and cerebrum form?
7 mnths
What structures does prosencephalon form?
Cerebral hemispheres
Later ventricles
Thalamus
Hypothalamus
3rd ventricle
What does mesencephalon form?
Midbrain
Aqueduct
What are secondary brain vesicles of prosencephalon?
Telencephalon
Diencephalon
What are secondary brain vesicles of rhombencephalon?
Metencephalon
Myelencephalon
What structures does rhombencephalon form?
Cerebellum
Pons & upper 4th ventricle
Medulla oblongata
Lower 4th ventricle
When does CNS abnormality occur?
2nd trimester
When does risk of disorders fall?
Wk 16
Most structures developed
What wk eye malformations?
Week 6
What week deafness?
Week 9
What week cardiac malformation?
5-10
When is dermal skin innervated?
28 wks
When does BBB develop?
8 weeks
What forms BBB?
Endothelial cells, pericytes, astrocytes
Function astrocytes?
Regulate blood flow
Regulate synaptic transmission
What does BBB form? (2)
Endothelial tight junctions
Continuous basement membrane
Give example structure doesn’t have BBB? Why
Posterior pituitary
Needs to be contact with blood- sensory role
When should neural tube close?
End week 4
What does failure of neural tube to close cause?
Spina bifida
What is anencephalus?
Failure neural tube to close in cephalic region
How measure neural activity?
Lumbar puncture
