Summary Skeletal Muscle Chapter 14

A snapshot of the summary - Skeletal Muscle Chapter 14

• 1 Embryonic origins and fetal development

• From which embryonic cell layer are skeletal muscles cells derived?

  The embryonic mesodermal layer
• What are the precursors of satelite cells?

  myoblasts that retain mitotic potential.
• Name the order of development of a muscle cell from stem cell to myofiber.

  • mesodermal stem cell
  • myoblast
  • primary myotube
  • secondary myotube
  • myofiber
• What is special about the connection between primary and secondary myotubes?

  They share the same basement membrane, until further development seperates the tubes by personal membranes.
• The soleus has mainly slow twitch fibers, what is thought about the origin of the soleus myofibers?

  They probably originate from primary myotubes.
• When during the gestation period are the first contractile elements formed?

  Around the ninth week of gestation.
• Which factors initiate the transition from myoblasts to myotubes?

  myf genes like myf5, myoD, MRF4 and myogenin
• Which factor inhibits the transition from myoblast to myotube?

  Myostatin, it inhibits the function of myoD
• When during the gestation do myotubes start to proliferate?

  From 11 weeks onward
• When during the gestation do tertiary myotubes occur?

  Around the 16th week.