Development of the Nervous System Flashcards
Process whereby the neural plate forms the neural tube
Neurulation
Lengthening of the neural plate and body axis by the phenomenon of ___________, whereby there is a lateral to medial movement of cells in the plane of ectoderm and mesoderm.
Convergent extension
During the _____ week of development, the ectoderm on the dorsal surface of the embryo between the primitive knot and the buccopharyngeal membrane becomes thickened to form the neural plate
Third
The neural folds continue to elevate, approach each other in the midline and finally fuse, forming the _____.
Neural tube
Neural fold fusion begins in the _____ region (___ somite) and proceeds in cephalic and caudal directions.
Cervical
5th
The cavity of the neural tube remains in communication with the amniotic cavity through the ___________
Anterior and posterior neuropores
The Anterior (Cranial) Neuropore closes at the ____-somite stage (____ day)
18 to 20 somite stage
25th day of gestation
Posterior (Caudal) Neuropore closes at ____-somite stage (_____ day)
25 somite stage
28th day of gestation
Three primary brain vesicles of the cephalic end of the neural tube
Prosencephalon
Mesencephalon
Rhombencephalon
Neural flexure at the junction of the rhombencephalon/hindbrain and spinal cord
Cervical flexure
Neural flexure at the midbrain region
Cephalic (Mesencephalic) flexure
By ___ week of development, the primary vesicles divide into the secondary vesicles
5th
The development of the optic vesicles come from which secondary vesicle?
Diencephalon
During the invagination of the neural plate to form the neural groove, the cells forming the _____ margin of the plate form a strip of ectodermal cells that lie between the neural tube and the covering ectoderm
Lateral
The strip of ectoderm that migrates ventrolaterally on each side around the neural tube and differentiates into the cells of the posterior root ganglia, the sensory
ganglia of the cranial nerves, autonomic ganglia, the cells of the suprarenal medulla, and the melanocytes.
Neural crest
Excessive numbers of neurons and neuroglial cells
are developed, and many (nearly half of the developing neurons) will be programmed to die by a process known as ___________.
Programmed cell death
The lateral edges of the neural plate soon elevate to form ________
Neural folds
The prosencephalon gives rise to which secondary brain vesicle/s
Telencephalon and Diencephalon
In the developing spinal cord, the wall of a recently closed neural tube consists of _______ cells
Neuroepithelial cells
Type of epithelium formed in the walls of the neural tube
Pseudostratified columnar epithelium
What do you call the primitive nerve cells that develop once the neural tube closes?
Neuroblast
What do you call the layer that surrounds the neuroepithelium in the developing spinal cord, and what cells form this layer?
It’s the mantle layer formed by the neuroblast
The layer surrounding the neuroepithelium forms which part of the mature spinal cord?
Grey matter
What do you call the outermost layer of the developing spinal cord containing nerve fibers from the neuroblast?
Marginal layer
As a result of myelination, the outermost layer of the developing spinal cord forms which part of the mature spinal cord?
White matter
As a result of myelination, the outermost layer of the developing spinal cord forms which part of the mature spinal cord?
White matter
What do you call the ventral thickening of the developing spinal cord?
Basal plate
The ventral thickening of the developing SC forms which areas of the mature spinal cord?
It forms the motor areas of the spinal cord or the anterior gray horn
The ventral thickening of the developing SC forms which areas of the mature spinal cord?
It forms the motor areas or the anterior gray horn
What do you call the dorsal thickening of the developing spinal cord?
Alar plates
The dorsal thickening of the developing SC forms which areas of the mature spinal cord?
It forms the sensory areas or the posterior gray horn
In addition to the ventral motor horn and the dorsal sensory horn, a group of neurons accumulates between the two areas and forms a small _____
Intermediate horn
This horn of the Spinal cord contains the sympathetic portion of the autonomic nervous system
Intermediate horn
The horn that forms the sympathetic portion of the autonomic nervous system can only be found in which segments of the spinal cord?
Thoracic (T1-T12) and Upper Lumbar (L1-L2/L3)
Before the cytoplasmic processes appears, the neuroblast, formed by the neuroepithelial cells, start as a/an _______ neuroblast
Apolar
The processes at one end of the bipolar neuroblast elongates rapidly to form the _______
Primitive axon
The processes on one end of the neuroblast shows a number of arborizations forming the ________
Primitive dendrites
These are primitive supporting cells formed by the neuroepithelial cells after stopping the production of neuroblasts
Gliablast
The gliablast differentiate in to which type of cells once it migrates to the mantle layer?
Protoplasmic and Fibrous Astrocytes
Which cells, derived from the gliablast, form the myelin sheath around the axons in the marginal layer?
Oligodendrocytes
These cells, derived from macrophages of the mesenchyme, migrate into the nervous system during fetal life
Microglia
When neuroepithelial cells cease to produce neuroblasts and gliablasts, they differentiate into ________ cells lining the central canal of the spinal cord.
Ependymal cells
These are group of cells, appearing along each ends of the neural folds, extend throughout the length of the neural tube
Neural crest cells
These cells migrate laterally and give rise to the dorsal root ganglia
Neural crest cells
The Neural crest differentiate into which cells/structures?
(Don't Say She Promised Open Marital Partnership) DRG Sympathetic Neuroblast Schwann cells Pigment Cells Odontoblasts Meninges Mesenchyme of the pharyngeal arches
In the development of spinal nerves, motor nerve fibers begin to appear in the _____ week
4th
The motor nerve fibers arising from the nerve cells of the basal plates of the spinal cord collect into bundles known as ________
Ventral Nerve Roots
These are collection of nerve fibers originating in the dorsal root ganglia
Dorsal nerve roots
The distal processes of the dorsal nerve roots join the ventral nerve roots to form the _______
Spinal nerve
The dorsal rami from the spinal nerve innervates which structures?
Dorsal axial musculature,
Vertebral joints,
Skin of the back
The dorsal rami from the spinal nerve innervates which structures?
Dorsal axial musculature,
Vertebral joints,
Skin of the back
The ventral rami of the spinal nerve innervate which structures?
Limbs and Ventral body wall
This division of the spinal nerves form the major nerve plexuses
Ventral Rami
