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28 Cards in this Set
- Front
- Back
Primary type of muscle precursor:
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Mesoderm
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3 types of muscle precursor origin:
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-Paraxial mesoderm
-Splanchnic mesoderm -Neural crest ectomesenchyme |
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What will splanchnic mesoderm form?
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Cardiac and smooth muscle (except goosebumps)
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What will paraxial mesoderm become?
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Skeletal muscle
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Where will muscle derived from Neural Crest ectomesenchyme form?
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In certain areas of the head, neck and upper thorax.
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Specific marker of cells destined to become muscle:
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MyoD gene
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ALL SKELETAL MUSCLE PRECURSORS ARE DERIVED FROM _________
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Paraxial mesoderm
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What is the main difference between Premyogenic mesoderm and Myoblasts?
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Premyogenic = mitotic
Myoblasts = postmitotic; can migrate |
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What are satellite cells?
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Mitotic cells that stay with muscle fibers so that in case of injury they become postmitotic and help repair.
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What are the 4 steps of muscle formation?
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1. Mitotic cells turn on MyoD
2. Post-mitotic myoblasts migrate & become muscle spcfc. 3. Myoblasts fuse -> Myotubes 4. Myotubes -> skeletal muscle |
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What are muscles in Head/Neck derived from?
Innervated by? |
Somitomeres & Occipital myotomes
-Cranial nerves |
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What are muscles in Trunk/Limbs derived from?
Innervated by? |
Paraxial mesoderm
-Spinal nerves |
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What is smooth muscle derived from?
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Splanchnic mesoderm
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What is unique about smooth muscle cells?
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Retain ability to divide
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What germ layers contain vscular smooth muscle precursors?
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All
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How does cardiac muscle differ from smooth?
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Immature cardiac myoblasts can divide while beating & maturing, but mature myocytes are postmitotic.
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What is the most common muscle to be absent due to malformation of muscular system?
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Sternocostal head of Pectoralis Major
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What is the syndrome where abdominal muscles are absent?
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Prune belly syndrome
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What is the disease in which there is fixed rotation and tilting of the head?
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Congenital Torticollis
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Family of genetic diseases w/ progressive deterioration of skeletal muscle:
(what is NOT in the pathology?) |
Muscular dystrophy - does not have nervous system pathology.
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Most common type of muscular dystrophy:
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Duchenne type
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Inheritance pattern of duchenne type MD
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X-linked recessive - in boys
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What is the problem in Duchenne type MD?
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Lack of Dystrophin in myocytes - myocytes susceptible to damage when physically stressed.
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How does Connective Tissue change as it matures?
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Embryonic CT: HI CELL:ecm ratio
Mature CT: High ECM:cell ratio |
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What is the only muscle to form from Ectoderm/Neural crest?
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Iris muscles
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What does lateral plate mesoderm associate with to form
-Skeletal components? -Splanchnic mesoderm/Muscle? |
Skeleton = w/ Ectoderm
Muscle = w/ Endoderm |
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What muscle forms from lateral plate splanchnic mesoderm?
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-Cardiac muscle
-Smooth muscle |
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What can vascular smooth muscle have as its precursors?
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Mesoderm OR neural crest
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