Summary Embryology of the Central Nervous System (CNS)

Embryology of the CNS
(preread)
Dr Minass
Ectoderm becomes the central nervous system



The notochord causes the ectoderm to thicken and develop into
the neural plate. The neural plate is what becomes the CNS



Neural crest cells form:

schwann ceslls

meninges

endocardial cushions

parafollicular cells

adrenal medulla




cranial/anterior neuropore - failure of this to close can
cause anencephaly


Embryology of the CNS (preread) 1

, caudal/posterior neuropore - failure of this to close can
cause spina bifida



anterior should close by day 25
posterior should close by day 27



after closure, the anterior part develops into 3 primary
vesicles: procencephalon, mesencephalon and rhombencephalon.


Parts of the brain

3 main parts of the brain:

procencephalon
(forebrain) →
telencephalon and
diencephalon

mesencephalon
(midbrain) → this
stays the same

rhombencephalon
(hindbrain) →
metencephalon and
myencephalon




Procencephalon

telencephalon becomes the cerebral hemispheres

diencephalon becomes the thalamus, hypothalamus and
epithalamus


Embryology of the CNS (preread) 2