Neuro Objectives 4
1.
Neural crest cells: Originate from the endpoints of ectoderm that will form the
future neural tube; after neural tube pinches off from ectodermal layer, neural crest cells
are left between ectoderm and neural tube. These cells will become PNS neurons and
glial cells.
2.
Name the origin:
Primary Vesicle
Secondary Vesicle
* think of cerebrum breakdown from lecture 1!
Cerebral Cortex:
Prosencephalon
Hippocampus:
Prosencephalon
Caudate Nucleus:
Prosencephalon
Putamen:
Prosencephalon
Amygdala:
Prosencephalon
Thalamus:
Prosencephalon
Hypothalamus:
Prosencephalon
Midbrain:
Mesencephalon
Pons:
Rhombencephalon
Cerebellum:
Rhombencephalon
Medulla:
Rhombencephalon
Telencephalon
Telencephalon
Telencephalon
Telencephalon
Telencephalon
Diencephalon
Diencephalon
Mesencephalon
Metencephalon
Metencephalon
Myencephalon
Pineal Gland:
Retina:
Prosencephalon
Prosencephalon
Diencephalon
Diencephalon
Lateral Ventricles:
3rd Ventricle:
Cerebral Aqueduct:
4th Ventricle:
Prosencephalon
Prosencephalon
Mesencephalon
Rhombencephalon
Telencephalon
Diencephalon
Mesencephalon
Metencephalon/Myencephalon
3.
Sulcus Limitans: Midline of spinal cord that separates dorsal and ventral sides
Alar Plate: Will become the dorsal aspect of the spinal cord (the posterior horn).
- Therefore, primary sensory nuclei will reside here
Basal Plate: Will become the ventral aspect of the spinal cord (the anterior horn).
- Therefore, lower motor nuclei will reside here
* Note: During development of the brainstem, the alar plates move lateral to the medial
basal plates. This occurs because the alar plate stays on the dorsal aspect which becomes
the superior part of the brain (remember the cephalic flexure). Since the alar plate is now
superior to the basal plate, and there is considerable pressure on the plates, the alar plates
are compacted and move to the lateral aspect of the spinal cord.
4.
Formation of C shaped cerebrum: The formation of a C shaped cerebrum
occurs because there is disproportionate growth of neocortex in the developing embryo.
This growth of neocortex pushes against a wall and curves into a C shape.
5.
Choroid plexus:
a.
cellular composition
a. made when pial layer (layer bordering subarachnoid space) touches
ependymal layer (layer bordering ventricle) with no CNS in between.
At these junctions, vasculature pushes cells inward and ependymal
cells form tight junctions to prevent free diffusion between blood and
brain. The ependymal cells actively pump out substances for CSF.
b.
adjacent spaces
a. in choroid plexus, ventricles directly border subarachnoid space
c.
locations in CNS
a. roof of inferior horn → body of lateral ventricles → intraventricular
foramen → roof of third ventricle
b. caudal floor of fourth ventricle
6.
Neural Tube problems:
Craniorachischisis: total failure of neural tube to close; tube is open to outside
 Lethal
Anencephaly: (“no brain”) caused by failure of neural tube to close on rostral end.
 Usually Lethal
Spina bifida: failure of neural tube to close on caudal end
 Superior failures cause more serious defects
 “Arnold-Chiari” malformations can occur also (cerebellum and caudal
brainstem elongation into foramen magnum)
Forebrain Differentiation problems:
Holoprosencephaly: since facial and forebrain differentiation overlap, these
problems are accompanied with facial defects.