Development of the Brain Flashcards
Secondary Vesicles
5th Week = 5 Vesicles
Forebrain: Telencephalon + Diancephalon
Midbrain: Mesencephalon
Hindbrain: Metencephalon and Myelencephalon
Primary Vesicles
Forebrain, Midbrain, Hindbrain form from neural folds in cranial region
CNS Regions of Neural Tube
- Brain develops during 3rd week from neural tube above 4th pair of somites
- Fusion of neural folds cranial region and closure of rostral neuropore form primary vesicles
Telencephalon Derivatives
Cerebral hemisphere and Lateral Ventricles
Diancephalon Derivatives
Thalami and Third Ventricle
Mesencephalon Derivatives
Midbrain and Aqueduct
Metencephalon Derivatives
Pons, cerebellum, and upper part of fourth ventricle
walls = form pons and cerebellum
cavity = forms rostral fourth ventricle
Myelencephalon Derivatives
Medulla and lower part of fourth ventricle
most inferior part of developing tube/brain
Brain Flexures
- initial spaces where NT folds on itself to fit in calvarium
- midbrain flexure, cervical flexure, pontine flexure
- flexures form as primary vesicles into secondary vesicles
Cervical Flexure
- separates hindbrain from spinal cord
- superior root of C1 at foramen magnum
Pontine Flexure
-separates metencephalon (rostral) from myelencephalon (caudal)
Agenesis of Corpus Collosum
absence of corpus collosum
can have no sx but seizures and mental deficiency
Growth of Cerebral Hemispheres
cortex initially smooth
growth results in sulci
gyri form from infoldings
sulci and gyri increase surface area without increasing volume of neurocranium
brain increase postnatally is from neurons increasing in size and axon myelination
Alar Plate of Medulla
lateral to basal plate form columns of neurons: 1. GVA 2. SVA 3. GSA 4. SSA also forms olivary nucleus on surface of medulla
Basal Plate of Medulla
medial to alar plate form motor neurons motor nuclei medial to sensory nuclei 1. GSE 2. SVE 3. GVE