Chapter 52 Flashcards
when fertilization has happened what element is then released that causes kinase and phsphatase activation
calcium
sperm donates entire nucleus to an egg cell
acrosomal reaction
calcium waves generates
morphological polarity
calcium binds to what that allows for binding to the kinase
camoduline
stage when embryo undergoes a compaction event at around 32 cells
morula
all blastocyst have
inter-cell mass
inter-cell mass of blastocyst is also called
epiblast
next layer in from the epiblast
hydroblast
cells can generate anything and everything from the whole genome, can generate germ layers and trophoblastic cells
totipotent
derived from the intercell mass of blastocyst, have the ability to generate germ layers
pluripotent
cells that make up parts of the placenta and the outside of the blastocyst
trophoblastic cells
after the blastula what occurs
gastrulation
gastrula has three layers from outside to inside
ectoderm
mesoderm
endoderm
gives rise to skin and the nervous system
ectoderm
gives rise to the heart, muscles, blood vessels, and blood cells
mesoderm
gives rise to many secretory organs like the pancreas and liver
endoderm
a little bit past gastrulation what occurs
neurulation
ectoderm under goes a series of events in neurulation
- starts to form a plate on the gastrula (neural plate)
- begins to divide and form neural groove
- wedge shape cells help with envagination of neural groove
overall neurulation has two parts
primary and secondary neurulation
what is formed ultimately from neurulaton
neural tube with neural fluid
cavity of brain and ventricles with CSF
what causes differences between the front and back of the embryo
cephalization
along neural tube what develops
neuroepithelial stem cells
the proencephalon froms the
forebrain
the mesencephalon forms the
midbrain
the rhombencephalon forms the
hindbrain
a cut blastocyst down the center gives rise to
two new organisms
a cut blastocyst down a side gives rise to
one new organism
what part of the ectoderm forms the formation of the nervous system
dorsal lip
mesoderm helps in the generation of the nervous system through
generation of the notochord
what must be present for the nervous system to develop
mesoderm overlying ectoderm
what signal represses neural differentiation
bone morphogenetic protein
how does the organizer overcome the repressor
noggin
chordin
follistatin
BMP promotes cells to become
epidermal cells
without BMP cells become
neurons
signals from the mesoderm and the endoderm define the _____of the neural plate
rostral caudal pattern
during rostral caudal pattern formation the endoderm secretes
WNT inhibitors in the anterior of the organism
during rostral caudal pattern formation the mesoderm releases
WNT
levels of WNT dictate expression of these
Otx2 and Gbx2
the midbrain-hindbrain boundary becomes the
isthmic organizer
regulate the morphology of tissues
morphogens
isthmic organizer produces
engrailed
basal conditions before WNT is in cell
Beta-catenin and GSK-3beta protein complex exists in the cytoplasm of cell
WNT causes this
- phosphorylation of beta catenin signals for its own degradation
- WNT binds to frizzled receptor and co-receptor LRP5
- GSK-3beta undocks from beta catenin to move to nucleus to regulate transcription
region in the diencephalon that secretes sonic hedgehog
zona limitans intrathalamica
sonic hedgehog released in the brain produces the
thalamus
engrailed induces synthesis of
WNT1 and FGF8
combination of FGF and Shh with Otx2 causes neurons to become
dopaminergic
combination of FGF and Shh with Gbx2 causes neurons to become
serotonergic
cues for generating the identity of dorsal or ventral spinal cord neurons comes from
ectodermal and mesodermal cells
signaling for the dorsal spinal cord comes from this first and then this
epidermal ectoderm then roof plate
signaling for the ventral spinal cord comes from this then transferred to this
notochord then transferred to floor plate
the release of certain morphogens causes the release of different or same morphogens
homogenetic induction
every cell has this that senses different types of signals
primary cilia
what is usually in cells under resting conditions
patchin
what does Gli produce during resting conditions
transcription regressor to turn cells off
what does sonic hedgehog gene first bind to in cell
patchin
what happens after sonic hedgehog binds to patchin
patchin comes out of cilia
smoothin moves into cilia freeing gli to go to the nucleus and stimulate transcription
are a group of related genes that control the body plan of an embryo along the cranio-caudal (head-tail) axis.
hoxx genes
hoxx genes on the 3’ end express
rostral end genes
hoxx genes on the 5’ end express
caudal end genes
Hoxx genes help with developing nervous system by
telling neurons where to project their axons
hoxx genes can generate these receptors
epherine
if an axon comes into contact with ephrin B receptors what happens
axon collapses and moves to a different region
these signals from the anteromedial telecephalon esablish the rostrocaudal pattern of the cerebral cortex
FGF8
transcription factors aiding in rostrocaudal gradients
Pax6 and Emx2
genetic elimination of Emx2 causes
expansion of the motor areas and contraction of the auditory and visual areas in the brain
elimination of the Pax6 gene causes
expansion of visual areas and contraction of motor and auditory areas
