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44 Cards in this Set
- Front
- Back
The characteristic event that happens during week three of development is called? |
gastrulation |
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Which of the following are derived from ectoderm? Adrenal cortex Connective tissue Gonads Peripheral nervous system Thyroid gland |
Peripheral nervous system |
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Which of the following are derived from endoderm? Dermis of the skin Epithelial lining of the rectum Epithelial lining of the lungs Epithelium of the pituitary gland Lymphaticsystem |
Epithelial lining of the lungs |
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Which of the following are derived from mesoderm? Adrenal medulla Lens of the eye Muscular system Parathyroidgland Skin glands |
muscular system |
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Which of these muscles is not made from mesoderm? • Cardiac muscle |
muscle tissue in sweat glands |
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Which region of the mesoderm will form serous membranes around organs? • Intermediate • Paraxial • Parietal • Visceral |
parietal |
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Which of the following genes is responsible for skeletal muscle differentiation from the mesoderm? • MyoD • MEF-2 • SRF |
MyoD |
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From which type of mesoderm does cardiac muscle originate from? • Extra-embryonic • Visceral layer of the lateral plate mesoderm |
visceral layer of lateral plate of mesoderm |
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during what phase are the 3 essential germ layers (mesoderm, ectoderm and endoderm) formed |
gastrulation |
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what tissue and parts of the body are derived from the ectoderm |
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what tissue and parts of the body are derived from the mesoderm |
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what tissue and parts of the body are derived from the endoderm |
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once the mesoderm layer is found, what sections does it divide into |
n= notochord |
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during what days does mesoderm differentiation take place and what mesodermic structures are formed during this period |
days 17-21 paraxial intermediate and lateral plate of mesoderm are formed |
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what portion of the mesoderm forms the somites |
paraxial mesoderm |
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what part of the body does the intermediate mesoderm form |
the genitourinary system (GU) |
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the lateral plate mesoderm is split into 2 layers by a cavity 1) what is the name of this cavity 2) name the 2 parts of the lateral plate mesoderm |
1) coleom 2) 2 parts of lateral plate: -Somatic/parietal layer -Splanchnic/visceral laye |
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on the following diagram identify the parietal/somatic and visceral/splanchnic layers of the lateral plate of the mesoderm |
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where does skeletal muscle originate from |
the paraxial mesoderm |
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from where does smooth muscle originate |
visceral/sphlanchnic layer of lateral plate of mesoderm around the gut tube |
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from where does the cardiac muscle originate |
visceral/sphlanchnic layer of lateral plate of mesoderm around the heart tube |
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the paraxial mesoderm gets organised into segments, what are these segments called |
somitomeres |
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what is the formation of somites known as |
somitogenesis |
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next to what structure do the somitomeres form |
the neural tube (becomes spinal cord?) |
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how many somitomeres form per day until week 5 and why is this medically relevant |
3 pairs of somitomeres form per day until week 5 this is medically relevant because it can be used to accurately determine the age of the embryo |
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by the end of the 5th week, 42-44 pairs of the somites are present, what are these? |
– 4 occipital – 8 cervical – 12 thoracic – 5 sacral – 5-7 coccygeal |
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what are the 2 genes which are expressed to regulate the formation of somites in an "oscillating pattern" |
NOTCH and WNT, NOTCH then accumulates in pre-somitic mesoderm |
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which gene is expressed cranially during the formation of the somites |
retinoic acid |
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which genes are expressed caudally (posterior/tail of body) during the formation of the somites |
FGF8 and WNT3a |
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how is notch activity controlled |
through overlapping gradients (of genes being expressed?) |
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what part of the somite forms the vertebra and ribs |
sclerotome |
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what part of the somite of the paraxial mesoderm forms the dermis of the back |
the dermatome of the somite |
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what part of the somite of the paraxial mesoderm forms majority of the bodies musculature |
the myotome |
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which 2 signalling molecules induce sclerotome formation |
sonic hedgehog and noggin |
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what 2 proteins combine to activate MYOD |
WNT (activating) BMP (inhibitory) MYOD is activated, creating a group of precursor muscle cells which express MYF5 |
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what is the role of MYOD / MYF5 (myogenic regulatory factors) |
they activate muscle specific genes and they can also convert non-muscle cells to muscle cells |
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what factor is responsible for cardiac muscle differentiation |
Serum response factor (SRF) |
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Serum response factor is upregulated by what kind of pathways |
kinase phosphorylation pathways |
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what enhances serum response factor activity levels |
Myocardin/ Myocardin related transcription factors
is a transcriptional cofactor of SRF levels |
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myoblasts are muscle precursors, when they fuse together, they form long, multi-nucleated fibres, what are these fibres called? |
myotubes |
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the formation of long mult-nucleated fibres called myotubes (in skeletal muscle) are under control of what 3 gene sets |
the 3 MYs:
– MYOD – Myf5 |
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where are tendons derived from in embryos and under what transcription factor are they controlled |
SCLERAXIS |
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in embryonic cardiac muscle, how do myoblasts adhere to each other |
via intercalated discs |
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lack of/ mutations in which human homolog can lead to serious heart defects |
NKX2.5 |