LG 1.13 Early Development of the Nervous System Flashcards
What happens at day 16-18?
Formation of neural plate
What happens at day 19-20?
Neural folds elevate
What happens at day 21-24?
Fusion of neural folds
What happens at day 25?
Cranial neuropore closes
What happens at day 27?
caudal neuropore closes
How does the ventricular system develop?
From the single cavity formed from the hollow neural tube
When is embryonic CSF formed?
Week 5
What does the neural tube give rise to (general)?
CNS
What happens during gastrulation?
Converts the bilaminar embryo to a trilaminar embryo
Where does the notochord form?
On the midline of the mesoderm
What does the notochord induce growth of?
Neural plate
What is Neurulation?
Folding of neural plate in to a closed tube of ectoderm
What results from failure to close anterior neuropore?
- Anencephaly
- Failure to develop brain, cranial vault
What is spina bifida?
- Results from incomplete closer of the embryonic neural tube.
- Usually sacrolumbar
What are the types of Spina bifida?
- Meningocele: protrusion of meninges
- Meningomyelocele: protrusion of meninges and spinal cord
- Rachischisis: open neural tube
What is one method of preventing neural tube defects?
Folic acid
When does Segmentation of the CNS happen?
4th week, 3 primary brain vesicles are formed
When does myelination begin?
3rd trimester and continues after birth
When does the most brain growth occur?
After birth
What does the prosencephalon give rise to?
- Telencephalon
- Diencephalon
What does the mesencephalon give rise to?
Mesencephalon
What does the Rhombencephalon give rise to?
Metencephalon and mylencephalon
What does the telencephalon become?
Cerebral hemispheres
What does the diencephalon become?
Thalamus and hypothalamus
What does the mesencephalon become?
midbrain
What does the met encephalon become?
pons and cerebellum
What does the mylencephalon become?
medulla
What does the myelon become?
spinal cord
What 3 layers does the neural tube form?
1) Ventricular Layer
2) Mantle Layer (Gray matter)
3) Marginal Layer (white matter)
What arises from the neural crest?
- Cranial and sensory ganglia and nerves
- Medulla of suprarenal gland
- Pigment cells
- Pharyngeal arch cartilages
- Head mesenchyme and connective tissue
- Bulbar and truncal ridges in heart
What is Hirschsprung’s disease?
- results from a failure of neural crest migration
- congenital aganglionic megacolon
- newborn has constipation without physical obstruction
- absence of ganglia in lower colon
- caused by mutation in several genes
