Lesson 10 Flashcards
This is the part of the nervous system that develops from the ectoderm, once it has differentiated into surface ectoderm and neuroectoderm.
Central Nervous System (CNS)
This part of the nervous system develops in association with the CNS and serves as the communication system between the CNS and the rest of the body.
Peripheral Nervous System (PNS)
This embryonic structure, formed from cells that invaginate and move towards the cranial end, eventually forms the notochord.
Primitive Node
This signaling molecule, essential for CNS development, signals the notochord to induce overlying ectodermal cells to differentiate into neuroectoderm.
Sonic Hedgehog
These molecules act between cells within close range and are involved in induction and embryonic cell patterning.
Paracrine Factors (or Morphogens)
This thickening of the ectoderm represents the primordium of the nervous system and is induced by the notochord.
Neural Plate
The process that ends with the formation of the neural tube involves these cells detaching from the neural tube, which are essential for PNS formation.
Neural Crest Cells
This is the process by which the neural plate folds to form a structure that will later develop into the CNS.
Neurulation
This structure is initially formed as a flattened tube that becomes the notochordal plate and eventually reforms into a tube to become the notochord.
Notochord
These are the two subdivisions of the ectoderm that form during the early stages of nervous system development.
Surface Ectoderm and Neuroectoderm
This embryonic structure acts as a signaling center, inducing the overlying ectoderm to begin forming nervous system structures.
Notochord
This structure forms from the neural plate and serves as the precursor to both the brain and spinal cord in the CNS.
Neural Tube
his term describes a series of steps where undifferentiated cells are guided to develop specific structures through signals such as Sonic Hedgehog.
Induction
These types of cells are essential in embryonic development, particularly in cell differentiation and spatial organization. They include Sonic Hedgehog and act locally between cells.
Morphogens
This process involves ectodermal cells differentiating and thickening to form the neural plate, under the influence of signals from the notochord.
Neural Induction
This signaling molecule is a well-known morphogen that plays a critical role in establishing the dorsal-ventral axis in developing neural structures.
Sonic Hedgehog
This gene was named by Robert Riddle after his wife saw an advertisement for a famous video game.
Sonic Hedgehog
This structure, positioned near the midline neural plate, releases Sonic Hedgehog molecules to aid neural development.
Notochord
This protein, produced by the surface ectoderm during gastrulation, prevents the dorsal ectoderm from forming neural tissues.
Bone Morphogenetic Protein-4 (BMP4)
These two molecules act as neural inducers by blocking BMP4, allowing the dorsal ectoderm to form neural tissue during neurulation.
Noggin and Chordin
This term refers to the single layer of cells that make up the neural plate and the neural tube before neurogenesis begins.
Neuroepithelium
Shortly after neural induction, this layer organizes into a structure that appears stratified but is actually a single layer due to its closely packed cells of different sizes.
Pseudostratified Epithelium
During the cell cycle, these structures within neuroepithelial cells shift extensively in the cytoplasm and migrate toward the lumen of the neural tube.
Nuclei
This structure, formed after the neural plate folds, is crucial to the development of the central nervous system and undergoes extensive cellular migration and division.
Neural Tube
When the cleavage plane is perpendicular to the apical surface of the neural tube, these cells migrate to the tube’s periphery for DNA synthesis.
Daughter Cells
This term describes the orientation of a dividing cell’s structure that determines the fates of its daughter cells within the neural tube.
Mitotic Spindle
When the cleavage plane is parallel to the apical surface of the neural tube, the daughter cell closer to this surface remains capable of mitosis and is considered a proliferative progenitor cell.
Inner (Apical) Surface
The daughter cell closer to the basal surface of the neural tube, which inherits a high concentration of a receptor regulating cell differentiation, is called this.
Neuroblast
These are the precursor cells of neurons that eventually develop cell processes, forming axons and dendrites.
Neuroblasts
This receptor regulates cell differentiation in neuroepithelial cells and plays a role in determining the fate of cells during neural development.
Notch Receptor
This molecule is secreted by cells of the notochord to override BMP4’s inhibitory effects, allowing neural tissue formation in the ectoderm.
Noggin and Chordin
This structure, a midline rod of cells, serves as a central signaling center during early neural development by releasing molecules like Sonic Hedgehog.
Notochord
This protein, produced by surface ectoderm cells, initially prevents neural development in the ectoderm by inhibiting the formation of neural tissue.
Bone Morphogenetic Protein-4 (BMP4)
This term refers to neural cells in development that are pluripotent/multipotent and capable of self-renewal through mitotic divisions, eventually maturing into progenitor cells.
Stem Cells
These progenitor cells can give rise to either neuronal or glial cell lineages during CNS development.
Neural Progenitor Cells
These structures are the cellular projections formed by neuroblasts that will become part of neurons, allowing them to connect and communicate.
Answer: Axons and Dendrites
Neuroblasts that extend branches, forming primitive dendrites, are called this type of neuroblast, which will eventually mature into neurons with multiple extensions.
Multipolar Neuroblasts
Once formed, these cells lose their ability to divide and will differentiate further by extending small processes from the cell body, forming primitive axons and dendrites.
Neuroblasts
This type of progenitor cell, derived from neuroepithelial cells after neuroblasts stop being produced, gives rise to various types of glial cells.
Glioblasts
These cells form from O2-A progenitor cells and create the myelin sheath around axons in the CNS.
Oligodendrocytes
These cells, derived from O2-A progenitor cells, play a role in homeostasis and the formation of synapses in the CNS.
Astrocytes
These cells form a framework in the brain that guides migrating neurons during development.
Radial Glial Cells
This layer surrounds the ventricular zone in the spinal cord and becomes the gray matter as development progresses
Intermediate (or Mantle) Layer
As the neural tube thickens and appears layered, these cells in the neuroepithelial layer become the lining of the central canal and the ventricular system of the brain.
Ependymal Cells
These cells, acting as motile macrophages, originate from outside the neuroepithelium and become active after CNS damage.
Microglia
This layer forms on the periphery of the spinal cord and becomes the white matter as neuroblasts develop axons and dendrites.
Marginal Layer
These are dorsal thickenings on either side of the neural tube during spinal cord development.
Alar Plates
These are ventral thickenings on either side of the neural tube during spinal cord development.
Basal Plates
The left and right alar plates are connected dorsally by this structure.
Roof Plate
These cells, originating from the edges of the neural folds, give rise to sensory ganglia of the spinal nerves, Schwann cells, and various other cell types.
Neural Crest Cells
This term describes the process in which the spinal cord, initially spanning the entire embryo, is later outgrown by the vertebral column, leaving the spinal cord’s posterior end within the column.
Ascensus Medullae Spinalis
This term refers to the extensive branching seen in neurons as they form dendrites and establish connections.
Arborization
In adult animals, the spinal cord terminates at these vertebral levels, though this varies slightly by species.
L2 to L3
Which part of the neural tube eventually forms the brain?
The anterior two-thirds of the neural tube.