Development of Nervous system Flashcards
From which layer of metencephalon does pons form?
marginal layer
Embryologic origin of pontine nuclei
alar plate of both metencephalon and myelencephalon
which structure forms the tela choroidea (choroid plexus) over the 4th ventricle?
myencephalon’s roof plate + pia mater
Developmental features of cerebellum by week 12? month 6?
Week 12: cerebellum has vermis and cerebellar hemispheres
Month 6: neuroblasts that migrated to form external granular layer differentiate into granule cells
Enumerate development of cerebellum
- alar plates of metencephalon approaching each other (very close below midbrain but remain separate above it)
- Formation of rhombic lips from alar plates
- Deepening pontine flexure compresses rhombic lips to form cerebellar plate which has the 3 layers of neural tube
Embryologic origin of superior and inferior colliculi
alar plates of mesencephalon; neuroblasts migrate to marginal layer
Functions of superior and inferior colliculi
Superior colliculi; visual relay station
inferior colliculi; auditory relay station
Embryologic origin of crus cerebri
marginal layer of midbrain’s alar plates
Structures formed from mesencephalon’s marginal layer.
Colliculi and Crus Cerebri
Briefly explain embryologic development of corpus striatum
Month 2; bulges from base of cerebral hemispheres grow into floor of foramen of monro
Embryologic development of hippocampus
Develops from thickenings of lateral walls of cerebral hemispheres above choroid plexus
*bulges into lateral ventricle
Which vesicles are covered by the cerebral hemispheres?
Diencephalon and Mesencephalon
When do gyri and sulci appear on brain surface?
final part of fetal life (weeks 28-40)
Define pallium
layers of gray and white matter covering cerebral hemispheres in IUL
Appearance of cerebral cortex at birth and the reason
Stratified because cells differentiating in layers
Cell types found in motor and sensory cortices of cerebrum.
Motor cortex has pyramidal neurons
Sensory cortex has granular neurons
Embryologic development of olfactory bulb
Based on interaction between floor of telencephalon and neural crest cells. Induces differentiation of mesenchymal cells into olfactory bulb.
Order in which anterior and hippocampal/fornix comissures, and corpus callosum appear.
- Anterior commissure
- Hippocampal commissue
- Corpus callosum
The diencephalon structure DOES NOT HAVE
Basal plate
Floor plate
*instead it has 2 alar plates and 1 roof plate
Embryologic origin of choroid plexus of 3rd ventricle
roof plate of diencephalon
Structures originating from roof plate of diencephalon
3rd ventricle’s choroid plexus + Pineal body
Structures from alar plate of diencephalon
thalamus
hypothalamus
mammillary bodies
