Ch. 9 Central Nervous System Flashcards
Neural Plate
Flat cluster of cells that will become neural tube
Neural Tube
Formed from folding neural plate
- Neural crest cells become neurons of PNS
- Outer layer becomes neurons and glia of CNS
- Inner layer becomes epithelial ependyma or stem cells
Spina Bifida
When neural tube fails to close
-Folate deficiency
Protective Mechanisms of CNS (5)
- Skull
- Meninges
- Blood/brain barrier
- Cerebral Spinal Fluid
- Vertebrae
Fontanels
Spaces where parts of skull have not fused
Chiari Malformation
Too large of opening at brainstem or too small skull
Vertebrae
33
Cervical, thoracic, lumbar, sacrum, coccyx
Meninges
Cushion the brain
Dura Mater
Arachnoid membrane
Pia Mater
Dura Mater
Outermost layer of meninges
-drainage of excess fluid
Arachnoid membrane
Middle layer of meninges
Pia Mater
Attached to surface of brain
-arterial blood supply
Meningitis
Inflammation of the meninges
Cerebrospinal fluid
- Synthesized by the choroid plexus
- Physical protection (brain floats)
- Chem protection (lower K and higher H)
- Waste removal
Blood brain barrier
capillaries in brain are more selective
-tight junctions b/w epithelial cells (induced by astrocytes)
Blood brain barrier transport
Requires transport proteins in cell membranes and lipid soluble molecules that can diffuse