slide flashcards W1D1
taratogen (def)
environmental factors (toxins, viruses, etc) that disrupt embryonic or fetal development
trisomy (def)
3 copies of a chromosome (down syndrome is example of non-lethal trisomy)
what is a baby called from weeks 3-8
embryo
during what period is a baby an embryo
weeks 3-8
what is a baby called from weeks 9-40
fetus
when is a baby called a fetus
weeks 9-40
what is the phase called before a baby is an embryo
preimplantation phase
how many days post conception does gastrolation occur
13-19 days post conception
what is invagination
the formation of the primitive streak along midline (during gastrolation)
in a blastocyst, what are the two components
epiblast and hypoblast (fluid filled cavity)
what is the trophoblast and what does it become
cells forming edge of blastula/blastocyst that becomes the placenta
what is a notochord
rod-like structure that defines the midline of the embryo and the position of CNS also sends signals to the ectoderm above to differentiate into the neural plate
the ectoderm thickens and grows into the BLANK over the BLANK
the ectoderm thickens and grows in the NEURAL PLATE over the NOTOCHORD
the cell devides from the midline (what stucture is there)
primitive streak notochord determins midline
cells continue deviding some faster than others forming the BLANK
neural groove
ridges of the neural ggroove join forming the BLANK which eventualy becomes the BLANK
ridges of the neural groove join forming the NEURAL TUBE wich eventually becomes the CNS
ectoderm columns are pinched off from each side of the neural tube (the sides of the neural tube are called the BLANK) which become BLANK and BLANK
ectoderm columns are pinched off from each side of the neural tube (called the NEURAL CREST) which eventually become sensory and autonomic ganglia (PNS)
what is the neural crest
ectoderm cells next to neural groove that are pinched off and become sensory and autonomic ganglia (PNS)
what does the notochord become in adult humans
nucleous pulposes in spine
what happens during prenatal developement if there is excessive vitamin a
can impede neural tube closer and differentiation
what are the meninges
protective membrains covering + surrounding brain
name the three meninges from out to in
dura matter, arachnoid matter, pia matter
through which layer of meninges do blood vessels flow
arachnoid matter/space
stem cell definition
a single cell that can either 1. replicate itself or 2. differentiate into many different cell types
what are the two zones during neurogenesis
ventricular and marginal zone
cells in the ventricular zone during neurogenesis will BLANK
continue to devide/devide again
cells in the marginal zone during neurogenesis will BLANK
eventually leave the ventricular zone and will differentiate into either neurons or glial cells
how do cells know where to go in brain + how do they get there
migrating cells ‘climb’ along radial glia and move away from ventricular layer, the migrating cells release molecules that guide other cells
what are radial glia cells
Cells. That. aid in cell migration (migrating cells ‘climb’ the radial glia)
where do radial glia cells come from
neuroepithelial cells
are radial glia cells precurser neurons
yes, radial glia are a type of precurser neuron cell and produce neuroblasts and glioblasts
what is lissencephaly
brain with no folds
the fate of a differentiating cell depends on both BLANK and BLANK
the fate of a differentiating cell depends on both its GENETIC PROGRAM and CHEMICAL SIGNALS it receives from its surroundings
gene expression is effected by BLANK to BLANK interactions
CELL to CELL interactions
what is process outgrowth
the extensive growth of young axons and dendrites
how do axons know where to point/go
guided by attracting chemical signals released by target cells
extensions at the tips of axons and dendrites are called BLANK
growth cones
why does neuronal cell death ocur
competition for synaptic sites, size of the target area, competition for chemicals (food), neurotropic factors
what makes neurotropic factors
target cells
what is a neurotropic factor
protien produced by target cell(s) which regulate expression of genes and affect development of the neuron
what 2 things influence synaptic survival/not dying
neural activity (use or lack of use) and neurotrophic factors
what does enrichment/an enriched environment effect (4)?
- more glial cells per neuron
- thicker cerebral cortex
- increased dendritic complexity
- increased synaptic efficacy
