2014 Group Project 8

From Embryology
2014 Student Projects
2014 Student Projects: Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6 | Group 7 | Group 8
The Group assessment for 2014 will be an online project on Fetal Development of a specific System.

This page is an undergraduate science embryology student and may contain inaccuracies in either description or acknowledgements.

Musculoskeletal

--Mark Hill (talk) 15:21, 26 August 2014 (EST) OK you have nothing here, not even a project title (that I added). I will be asking your group questions in the lab tomorrow. How about some content, references, sources for each section. See Lab 3 Assessment.

Making Gains

For all you big boys out there who want to get jacked this is where it all starts in 2 easy steps. To be expanded upon...THIS IS NOT BROSCIENCE

Muscle development General Timeline

Primary myofibers develop in first trimester, Secondary myofibers develop during Second and Third Trimester We should do a brief overview of primary myofiber formation, and extensive overview of secondary myofiber formation)

Background Embryonic development

Mesenchymal progenitor cells from somites(occiptal, cervical, thoracic, lumbar, sacral), undergo multiple differentiation stages to create muscle fibers.

http://www.mdconsult.com/books/figure.do?figure=true&eid=4-u1.0-B978-1-4377-2002-0..00015-1--f0025&sectionEid=4-u1.0-B978-1-4377-2002-0..00015-1&isbn=978-1-4377-2002-0&uniqId=464007141-2 (demonstration of myotomes in week 6 and 8)

Muscle develops from a process known as myogenesis. There are 3 types of muscle; cardiac, smooth and skeletal. In embryogenesis skeletal muscle is derived from the somites. Somites are mesodermal structures where the dorsal most end of the somite, which is known as the dermomyotome, becomes skeletal muscle and dermis [1].

A region known as the myotome which lies inbetween the scleratome which is ventrally located and the dermomyotome which is located dorsally which forms the first skeletal muscle in the embryo.

The medial part of the dermomyotome forms the dorsal and intecostal muscles whilst the lateral part of the dermomyotome forms the limb and ventral muscles [2]. Trascription factors Pax3 and Pax7 In these regions MyoD and other transcription factors activate muscle encoding genes. These transcription factors belong to a group known as myogenic bHLH (basic helix loop helix).

During the embryonic phase primary myogenesis occurs. In primary myogenesis myoblasts fuse to form myotubes. Primary myotubes express MHC slow myosin heavy chains [3]. The primary myotubes form the structure and scaffold upon which secondary myotubes form during secondary myogenesis which occurs in the fetal period [4].

Second Trimester Muscular development

Cranial muscles originate from head mesoderm

1st Arch Muscles for Mastication:

2nd Arch Muscles for Facial Expression:

3rd Arch: Stylopharyngeus

4th Arch: Levator Palatini, Intrinsic Muscles of Larynx and Pharynx

Myotomes from Somites (From lect) C3,4,5: supply the diaphragm for breathing. C5: supply shoulder muscles and muscles to bend our elbow. C6: for bending the wrist back. C7: for straightening the elbow. C8: bends the fingers. T1: spreads the fingers. T1-T12: supplies the chest wall and abdominal muscles. L2: bends the hip. L3: straightens the knee. L4: pulls the foot up. L5: wiggles the toes. S1: pulls the foot down. S3,4,5: supply the bladder, bowel, sex organs, anal and other pelvic muscles.


Third Trimester Muscular development

NeoNatal

Not all embryonic muscle fibers persist; many of them fail to establish themselves as necessary units of the muscle and soon degenerate. (Moore: The Developing Human, 9th ed.)

Mechanism/Structure of Muscle fibers

Muscle Fiber types

slow twitch (Type I) fast twitch (Type IIa) fast twitch (Type IIb)

For fiber types I think we should only do that of the skeletal muscle fiber types since cardiac and smooth muscle are not part of the musculo-skeletal system

Abnormalities

Types of Muscular Dystrophy; Duchenne Muscular Dystrophy, Becker type muscular Dystrophy, Occulophayngeal muscular Dystrophy,

Absence of specific muscles;

References

Anatomy and variations of palmaris longus in fetuses.[5]

Development of the rectus abdominis and its sheath in the human fetus.[6]

Sonic hedgehog acts cell-autonomously on muscle precursor cells to generate limb muscle diversity.[7]

The normal growth of the biceps brachii muscle in human fetuses.[8]

  1. <pubmed>9094722</pubmed>
  2. <pubmed>9094722</pubmed>
  3. <pubmed>21204650</pubmed>
  4. <pubmed>21204650</pubmed>
  5. <pubmed> 23529313</pubmed>| [1]
  6. <pubmed> 22869489</pubmed>| [2]
  7. <pubmed> 22987640</pubmed>| [3]
  8. <pubmed>23468258</pubmed>| [4]

Abnormalities

1 Scoliosis 2. Duchenne Muscular Dystrophy 3. Syndactyly : split-hand malformation

R Geoffrey Burwell, Peter H Dangerfield, Alan Moulton and Theodoros B Grivas. (2011). Adolescent idiopathic scoliosis (AIS), environment, exposome and epigenetics: a molecular perspective of postnatal normal spinal growth and the etiopathogenesis of AIS with consideration of a network . Scoliosis. 6 (6), p1-26

(links: http://www.scoliosisjournal.com/content/6/1/26)

Patrizia Pessina, Daniel Cabrera, María Gabriela Morales, Cecilia A Riquelme, Jaime Gutiérrez, Antonio L Serrano, Enrique Brandan and Pura Muñoz-Cánoves. (2014). Novel and optimized strategies for inducing fibrosis in vivo: focus on Duchenne Muscular Dystrophy. Skeletal Muscle. 4 (7), p1-17

(links: http://www.skeletalmusclejournal.com/content/4/1/7)

Naeimeh Tayebi, Aleksander Jamsheer34, Ricarda Flöttmann1, Anna Sowinska-Seidler, Sandra C Doelken. (2014). Deletions of exons with regulatory activity at the DYNC1I1 locus are associated with split-hand/split-foot malformation: array CGH screening of 134 unrelated families. Orphanet Journal of Rare Disease. 9 (108), p1-9

(links: http://www.ojrd.com/content/9/1/108)

Recent findings

References

To be properly referenced at a later date

http://www.journalofanimalscience.org/content/89/2/583.full

http://www.jgenomics.com/v01p0029.htm