Unit 2 - Chapter 4 Reading Flashcards
The embryo consists of three layers of cells, which are:
- endoderm
- mesoderm
- ectoderm
the outermost cellular layer of the developing embryo, giving rise to the skin and the nervous system.
ectoderm
List the 6 stages of cellular processes needed for brain development.
- neurogenesis
- cell migration
- cell differentiation
- synaptogenesis
- neuronal cell death
- synapse rearrangement
The beginning of the central nervous system occurs when the tops of the neural groove come together to form the —————.
neural tube
the frontal division of the neural tube, which in the mature vertebrate contains the cerebral hemispheres, the thalamus, and the hypothalamus
forebrain
the middle division of the brain
midbrain
the rear division of the brain, which in the mature vertebrate, contains the cerebellum, pons, and medulla
hindbrain
the earliest stage in a developing animal; humans are considered to be ———– until 8-10 weeks after conception
embryo
a developing individual after the embryo stage; humans are considered to be ——– from 10 weeks after fertilization until birth
fetus
What is neurogenesis?
the mitotic division of nonneuronal cells to produce neurons
What is cell migration?
the massive movements of nerve cells or their precursors to establish distinct nerve cell populations (nuclei in the CNS, layers of cerebral cortex, etc.)
What is cell differentiation?
the refining of cells into distinctive types of neurons or glial cells
What is synaptogenesis?
the establishment of synaptic connections as axons and dendrites grow
What is neuronal cell death?
the selective death of many nerve cells
What is synapse rearrangement?
the loss of some synapses and the development of others, to refine synaptic connections, which extends throughout our lifespan
Compared to humans, chimps brain development after birth is ————–.
modest; humans seem to have much more brain development that occurs after birth
The protracted brain development post-birth results in a much ———- brain relative to body size, in humans than other apes or Old World monkeys.
larger
The production of neurons is called ————-.
neurogenesis
the mitotic division of nonneuronal cells to produce neurons
what is the process by which cells divide?
mitosis
process of division of somatic cells that involves duplication of DNA
another word for the ventricular zone
ependymal layer
a region lining the cerebral ventricals from which new glial cells are born throughout life, via mitosis
ventricular zone
What is it alled when cells move over relatively long distances to fill out the brain?
cell migration
the movement of cells from site of origin to final location
the turning off of specific genes; the process by which a cell makes an mRNA transcript of a particular gene
gene expression
process of —————————— enables cells to acquire the distinctive appearance and functions of neurons characteristic of their particular regions
cell differentiation
the establishment of synaptic connections as axons and dendrites grow
synaptogenesis
the hallmark of vertebrate devlepment cells sort themselves out via ———————
cell-cell interactions
the general process during development in which one cell affects the differentiation of other, usually neighboring, cells
cell-cell interactions
What is an important consequence of the cell-cell interactions’ impact on brain development?
if cells that have not yet differentiated extensively can be obtained and placed in a certain brain region, they can differentiate in an appropriate way and become properly integrated
stem cells
cells that are undifferentiated and therefore can take on the fate of any cell that a donor organism can produce
True or False: At birth, mammals have already produced most of the neurons they will every have.
True
4.1
What causes postnatal brain growth?
- size of neurons
- branching of dendrites
- eleboration of synapses
- increase in myelin
- addition of glial cells
4.1
Define adult neurogenesis.
generation of new neurons in adulthood (especially in the dentate gyrus of the hippocampal formation)
4.1
True or False:
Research in animals shows that the birth of and/or survival of new neurons is enhanced by factors like exercise, environmental enrichment, and training.
True
4.1
True or False:
Cell death is bad for brain development.
False; cell death is a crucial phase of brain development
4.1
What is another word for cell death?
apoptosis
4.1
True or False:
In some regions of the brain and spinal cord, most of the young nerve cells die during prenatal development.
True
4.1