2: Development of NS Flashcards
What is the embryonic origin of the NS?
Ectoderm
Trilaminar germ disc:
- Ectoderm (Skin and NERVOUS SYSTEM)
- Mesoderm
- Endoderm
What is the origin of the Notochord?
Cells migrating from primitive node + pit
Forms during gastrulation
How are the Neural Plate, Groove and Tube formed? (3 steps)
- Overlying ectoderm differentiates → Neural plate
- Neural plate thickens → lat. edges rise up → midline regresses → Neural groove
- Lat. edges meet @ midline → fuse → Neural tube
What are the 2 types of Neural Tube Defects?
- Cephalic NTD’s
- Spinal NTD’s
What is an example of a Cephalic Neural Tube Defect?
Anencephaly (Absent brain / skull / scalp)
- Cephalic end of neural tube fails to close
What is an example of a Spinal Neural Tube Defect?
Spina Bifida (2 types)
- SB Occulta
- SB Cystica
What are the features of Spina Bifida Occulta? (3 things)
- Failure of inferior neuropore closure
- Vertebral arches don’t develop in caudal area
- Spinal cord function: NORMAL
What are the features of Spina Bifida Cystica? (2 things)
- Cyst @ caudal end of spine
- Spinal cord function: IMPAIRED
Which type of Spina Bifida has NORMAL spinal cord function?
SB Occulta
nOrmal : Occulta
What are the brains ventricles formed from?
Neural tube lumen (3 parts):
- Telencephalon→ Lat ventricles
- Diencephalon → 3rd ventricle
- Rhomboencephalon → 4th ventricle
What are the signs of Cerebral Palsy? (3 things)
- Dyskinesia (invol movements + muscle tone changes)
- Athetosis (slow writhing limb movements)
- Rigidity
DAR DAR gaddafi innit
What are the effects of Cerebral Palsy? (3 things)
- Learning difficulties
- Epilepsy
- Speech, hearing, eye sight difficulties
What are the types of glial cells in the CNS? (4 things)
- Astrocytes
- Oligodendrocytes
- Microglia
- Ependymal cells
Where are Astrocyte glial cells found?
Brain + spinal cord
What are the functions of Astrocyte glial cells? (2 things)
- Maintain eletrochemical environment for neurons
- Help form BBB