Development of the Neuromuscular System Flashcards
Muscle and connective tissue is mostly developed from
Mesoderm
Nervous tissue is mostly developed from
Ectoderm
is the alar plate on the roof plate side or the floor plate side
roof plate
Is the basal plate on the floor plate side or the roof plate side
floor plate
What kind of cells surround the central canal during the 4th week of developement
undifferentiated neuroepithelial cells
The early neural tube consists of ___________ epithelium
psuedostratified columnar
The cellular division and maturation of the neural tube cells leads to what
a population of bipotential progenitor cells
What do the bipotential progenitor cells become
which will give rise to either neuronal or glial lineage progenitor cells
What is the function of neuroglia cells
supporting cells of the CNS. Insulate, nourish, support and protect neurons
What does the marginal layer contain
neuronal processes (axons) white matter
What does the the mantle layer contain
cell bodies (gray matter)
_____ and ______ migrate outward to form a intermediate mantle or cortical zone. This will become the inner grey matter that contains neuronal cell bodies and neuroglia
Postmitotic neurons, glioblasts
Neuronal process (myelinated) move out to surround the developing grey matter and form the ______
Marginal zone (outer white matter)
In molecular regulation of nerve differentiation in the spinal cord ____ and ____ in the ectoderm establish a signalling center in the roof plate
BMP4 and BMP7
In molecular regulation of nerve differentiation in the spinal cord BMP4 in the roof plate upregulates a cascade of _____, incluiding ____ and ____, ____, and ______
TGF-beta proteins, BMP5 and BMP7, activin, dorsalin
in molecular regulation of nerve differentiation in the spinal cord SHH from ______establishes additional SHH signaling in the floor plate
Notochord
What are the three division of mesoderm
Paraxial mesoderm, intermediate mesoderm, lateral plate mesoderm
Where is paraxial mesoderm located
longitudinal blocks of tissue on either side of the notochord.
What does paraxial meosderm give rise to
axial skeleton and skeletal muscle
What does the intermediate mesoderm give rise to
Gives rise to the urogenital system (don’t forget urinary and GONADS)
What does lateral plate mesoderm give rise to
CT and skeleton of the limbs and smooth muscle and CT of viscera and blood vessels.
Which of the three divisions of mesoderm does skeletal muscle come from
Paraxial Mesoderm
Somites for in what direction
caudally from the occipital region
Segmentation is controlled by __________
pulses of gene expression
After paraxial mesoderm differentiates into somite what three divisions are next
Sclerotome, myotome, dermatome
The myotome becomes
skeletal muscle
The dermatome becomes
Dermis
The sclerotome becomes
Cartilage template for skeletal system
Lateral mesoderm becomes what 3 divisions
Splanchnic (circulatory system) and viscera
Somatic (body cavity)
Extra-embryonic
The _______ is an evolutionarily conserved intercellular signaling pathway that regulates interactions between physically adjacent cells
Notch signaling network
Molecular regulation of somite formation is largely regulated by
Notch signaling network
_____ protein accumulates in presomitic mesoderm destined to form the next somite and then decreases as that somite is established. The increase in ____ protein activates other segment-patterning genes that establish the somite
Notch, Notch
Boundaries for each somite are regulated by ______ and a combination of ____ and _____
Retinoic acid (RA), FGF8, WNT3a
_____ is expressed at high concentrations cranially and decreases in concentration caudally during somite formation
Retinoic Acid (RA)
During somite formation ___ and ____ are expressed at higher concentrations caudally and lower ones cranially
FGF8 and WNT3a
The overlapping expresion gradients of ____, ____, ____ control the segmentation clock and activity of the NOTCH pathway
Retinoic acid, FGF8 and WNT3a
In snakes the segmentation clock ticks fast or slower than humans
around 4 times faster
What are the three divisions of a somite
Sclerotome, Dermamyotome ( which divides into dermatome and myotome)
Where is the sclerotome located
ventromedial portion closest to the notochord
The dermatome forms the
dermis (located under the epidermis in the skin)
What does myotome give rise to
muscles
Explain resegmentation
takes place only in the sclerotome. the rostral and caudal halves of somites segregate, and re-fuse with their neighbouring halves to form vertebra this is important for creating a space that spinal nerves go through
Cells of the sclerotome condense around the notochord and form the _____
Vertebrae
The notochord forms the _______ in intervertebral disk (between vertebra)
Nucleus pulposus
Vertebral differentation is controlled by
Hox gene interaction
Hox 5 leads to the formation of
Cervical vertebra
Hox 6 and Hox 9 together leads to the formation of
Thoracic vertebra
Hox 10 leads to the formation of
Lumbar, Sacral, and Coccygeal
What are two members of a family of transcription factors called myogenic regulatory factors (MRFs)
MyoD and MYF5
Myf5 leads to myotome differentation into what
Hypaxial muscle only
MyoD leads to myotome differentation into what
epaxial muscles
The doral ramus innervates
The epaxial muscles
Where does intermediate mesoderm move as it further developes
Moves to position on posterior abdominal wall
What does the intermediate mesoderm form
forms gonads (excpet primitive germ cells) Forms ducts, accessory glands of urinary and reproductive tract
Lateral plate mesoderm divides into two divisions
Somatic and Spalnchnic
The somatic lateral mesoderm forms
The wall of the body cavity
The splanchnic lateral mesoderm forms
visceral, “internal organs” (innervated by the autonomic nervous system)
The neuronal lineage progenitor cells give rise to
neurons
The glial lineage progenitor cells give rise to
neuroglia cells
What cells line the central canal
ependymal cells
Astrocytes and oligodendrocytes are in found in what layer
The marginal layer
The radial glia cell body is located in the ___ layer
Ventricular layer, put it has processes that extend through the intermediate (mantle layer) and into the marginal layer
