Glossary of Embryo - Nervous System Development
Other Decks By This User
- Neural tupe formation is induced by ________
- Notocord/middle 3rd week
- Describe closure of neural tube. When is it complete?
- begins in middle , continues anteriorly and posteriorly. Neuropores at both ends.
Completes late in 4th week.
- Neural plate developes into 3 zones. What are they? Describe them.
- 1) Ventricular zone (original cell source)
2) Intermediate zone (cell proliferation and differentiation; future gray matter)
3) Marginal zone (future white matter)
- The immediate zone is further divided into
- Alar plate (dorsal; sensory)
Basal plate (ventral; motor)
- Derivitives of Neuroectoderm
- develop directly into ventricular lining cells
- nerve cell precursors
- differentiates int astroglia and oligodendrocytes
- Derivitives of the INTRAEMBRYONIC MESODERM
- Neural crest Derivitives make up ____ components.
- What are the neural crest derivitives?
Describe what they make?
- PNS components
Ganglion nerve cells (sympathetic, parasympathetic, and unipolar cells)
Peripheral support cells (schwann cells [neurilemmicytes] & satellite cells)
- Formation of Histological Regions
- Intermediate zone - parts inside, where cell bodies differentiate, forms gray matter
Marginal- the parts outside, where axons grow and become myelinated, forms white matter
Ventricular - the cells adjacent to central canal and ventricals, which are the initial proliferative cells and which eventially develop into ependyma.
- When does Myelination begin, when does it end?
- Begins 16-20 weeks intrauterine, complete around 2 yrs
- Cytological modification that happens during fetal period.
- cell death (timing and percentage of cells depends on site)
- Cytological modification that happens during postnatal period.
- synapse elimination
- Alar plate is located where in the embryo
- dorsal and lateral sulcus, sensory areas
- Basal plates is located where in the embryo
- ventral to lateral sulcus, forms motor areas
- Where are somatic regions of alar and basal plates located?
- extreme ends: farthest dorsal 1/4 is somatic sensory and farthest ventral 1/4 is somatic motor
- Where are visceral regions of alar and basal plates located?
- adjacent to lateral sulcus; dorsal part is visceral sensory, ventral part is visceral motor (autonomic
- describe sensory/motor organization of spinal cord
- most like embryonic pattern.
dorsal horn- snesory
intermediolateral grey column-autonomic motor
- describe sensory/motor organization of medulla oblongata
- Roof of rhombencephalon is expanded so sensory columns are most lateral, motor columns most medial
- describe sensory/motor organization of midbrain
- Sensory parts are dorsal to aqueduct, motor parts are ventral to aquaduct
- spinal cord fills canal at ___
- 8 wks
- Terminal end of spinal cord is roughly at ____ birth
- L3 (+/- 1 vert level)
- Spinal cord terminates where in adult?
- cause of spinal bifida
- spinal cord is the last area to close.
A delay in closure causes the mesoderm to miss it's developmental 'window' in forming the dorsal arch of the vertibrae.
- spinal bifida occulta
- not conspicuous without close examination
- spinal bifida cystica
- conspicuous sac
- most proximal of the three sections of developing brain.
-Consists of Telencephelon & Diencephelon
- Telencephelon describe it's size, when it developes and what it consists of.
- Largest and last of the regions to develop.
- Diencephelon. What does it connect, what is it's function, and what does it consist of.
- Connects the telencephelon to brainstem, involved with significant neural processing
Consists of :
- Midbrain region
-contains several important nuclei, connects to rhombencephalon
Where is it located and what does it consist of?
- Most posterior part of brainstem
- Metencephelon consists of
- Pons - what does it connect and contain
- connects medulla w/ midbrain, contains several important nuclei
- side-branch; major motor part of brain
- Myencephelon consists of
- Medulla oblongata
- Medula oblongata. What does it connect and contain.
- connects brainstem to spinal cord; contains several important nuclei
- Flexures are
- bends in the brainstem
name and describe
- cervical - between spinal cord and myencephalon
cranial - at midbrain
- Cortical differentiation
- intermediate zone becomes thick. refered to as Germinal matrix. All cells of Cortex differentiate from it.
Cells of cerebral cortex migrate through marginal zone. Three waves of migration: ssecond migrates through the first wave, and the third migrates through the 1st and second waves.
By 34 weeks, this migration is complete and germinal epithelium becomes a series of cortical nuclei adjacent to the ventricals
- Anencephaly. What is it What part of brain is typically effected.
- Absence of part of skull or brain.
usually only prosencephalic sx affected (generally the telencephalon will always be affected, with more or less involvement of the diencephelon. Brain stem may or may not be affected, or affected only mildly.
- inadequate development of brain leading to small size (mult causes)
- Cranium bifidum
- similar to spinal bifida; a part of the cranium does not develop due to delay in closure of skull
- hydrocephalus. What is it? What part of the brain can be crushed? What is most common cause?
- Fluid pressure build-up inside ventricle which causes cranium to expand. -will crush telencephalon if left unchecked.
most common cause is blockage of cerebral aqueduct.
You must Login or Register to add cards