Susie Chapter 8 Flashcards
this is a set of instructions for making an organ of the body
genome
the first step in brain development is …
cell division
when individual cells stop dividing and take on specific characteristics (signals from different areas of neural tube turn on/off genes in different cells) -such as those of neurons or glial cells, this orders things spatially. this process is called…
cell differentiation
different kinds of neurons migrate to various locations is called…
pattern formation
this is formed by small patch of cells, the front is destined to form the brain, the rear to be the spinal cord. occurs during the 3rd week of human gestation.
neural plate
failure closure at the head end can result in the complete absence of an organised brain, a condition known as …
anencephaly
failure of neural tube closing at the lower spinal cord results in…
spina bifida
embryo sets up a number of localised __ regions in the neural tube that secrete signal molecules
polarizing
the molecule diffuses away from its source to form a __ of concentration with distance.
gradient
higher concentration of sonic hedgehog induces the expression of a gene that makes what type of neuron?
interneurons
lower concentration of sonic hedgehog induces expression of a gene that makes what type of neurons?
motor neurons
once a neuron stops dividing, it extends its axon with an enlarged tip (specialized for moving through tissue, suing its skills to select a favourable path) known as…
growth cone
this the cell of the body with the potential to change into all sorts of different kinds of other cells
stem cells
guidance cues from distance: chemorepulsion is called…
semaphorins
guidance cues from distance: chemoattraction is called…
netrins
guidance cue for contact attraction is called…
cadherins
guidance cue for contact repulsion is called…
ephrins
endoderm is the first layer of embryo, it is responsible for which area （1）of the body?
organs
mesoderm is the second layer of embryo, it is responsible for which areas （3）of the body?
muscles, bones, connected tissue
ectoderm is the third layer of embryo, it is responsible for which areas (2) of the body?
nervous system, skin
oocyte+sperm cell=zygote (name this process)
fertilization
zygote → blastula (name this process)
cleavage
blastula → three-layered embryo (name this process)
gastrulation
three-layered embryo → three-layered embryo with neural tube (name this process)
neurulation
what releases sonic hedgehog and directs process to happen?
notochord
neurulation occurs on the __ week after fertilization.
3rd
gastrulation occurs on the __ week after fertilization.
2nd
true or false
neural development occurs from fertilization to neurulation
false.
it occurs throughout lifetime.
during which stage does cells of the blastyla rearrange themselves into three layers?
gastrulation
on which stage does the process of differentiation happen?
gastrulation
what is formed when the neural plate invaginates (fold in)?
neural tube
how many genes are there in the human genome?
40,000
true or false
fruit flies can be used to study human neuro-development because we share many of the same genes.
true
what do we call the window of time when sensory stimulation is required for neurons to develop properly? (initial exuberant set of connections is sculpted during this period.)
critical period
