Development of the Brain Flashcards
2.13.2025
Explain the ectoderm.
Outer cellular layer of the developing embryo that later differentiates into integumentary and nervous system, also pituitary.
Explain the mesoderm.
The middle layer between the ectoderm and endoderm that later differentiates into muscle, bone, gonad, heart, red blood cells, and some connective tissue.
Explain the endoderm.
The innermost layer of tissue that later differentiates into epithelial layers of lungs, GI tract, liver, pancreas, bladder, thyroid, and parathyroid glands.
Name the six sequences of brain embryonic brain development.
I. neurogenesis
II. cell mirgation
III. Cell differentiation
IV. Synaptogensis
V. Neuronal cell death
VI. Synapse rearrangement
Explain neurogensis
after the formation of the ecto, endo, and mesoderm, the mitotic division of non-neuronal cells produce neurons.
Explain cell migration.
The massive movements of nerve cells or precursors to establish distinct nerve cell populations.
Explain cell differentiation
the refining of cells into distinctive types of neurons or glial cells
Explain synaptogenesis
the establishment of synaptic connections as axons and dendrites grow
Explain neuronal cell death
selective death of many nerve cells
Explain synapse synapse rearrangement
The loss of some synapses and the development of others, to refine connections- extends throughout lifespan.
Explain what mitosis is.
Process of division of somatic cells that involves duplication of DNA
Where does mitosis take place?
ventricular zone of the neural tube
Explain what gene expression is.
cells begin to use, or express (used to make something functional, such as protein), particular genes
What are cell-cell interactions?
general process during development in which one cell affects the differentiation of the other, usually neighboring cells.
What are stem-cells?
a cell that is undifferentiated and therefore can take on the fate of any cell that a donor organism can produce. Present throughout the embryonic tissue. Treats degenerative disorders
What is adult neurogenesis?
creation of new neurons in the brain as an adult
What is cell death?
apoptosis; surplus cell dies
programmed cell death. chops up everything in the cell
Explain Fragile X syndrome.
a condition that is a cause of inherited intellectual disability and is produced by a fragile site on the X chromosome that seems prone to breaking because DNA is unstable
visual deprivation
What is amblyopia?
reduced visual acuity of one eye that is not caused by optical or retinal impairments
What is sensitive period?
period during development in which an organism can be permanently altered by a particular experience or treatmen
What is genotype?
all the genetic information that an individual
inherits. fixed at birth
What is phenotype?
the sum of an individual’s characteristics at one particular time. changes throughout life
Experience and Expression
What is phenylketonuria?
PKU; disorder of protein metabolism that in the past resulted in intellectual disability; leads to a toxic buildup of phenylalanine metabolites
Experience and Expression
What is epingenetics?
study of factors that affect gene expression without making any changes in the nucleotide sequence of the genes
Experience and Expression
What is Methylation?
chemical modification of DNA that does not affect the nucleotide sequence of a gene, but makes that gene
less likely to be expressed
