musculoskeletal development - muscles and innervation Flashcards
what triggers the growth of spinal nerve from the spinal tube?
the presence of somites
does the dermamyotome get split by the spinal nerve?
no
what is a dermatome?
area of skin supplied by a single spinal nerve and its ganglion.
why are dermatomes not even in an adult? (even in embryo)
because the limbs rotate
where does the myotome move to?
forms a population of cells:
- down the back - epimere
- around the ventral surface - hypomere
what will the division between the epimere and hypomere form into?
the transverse processes of spinal vertebrae.
what do the two streams of myotome that migrate from the hypomere develop into?
- extensor compartment
2. flexor compartment
what is the division of everything controlled by?
by the signalling molecules in the adjacent tissues.
how do the cells in the myotome form the myofibrils?
they are myogenic precursors that fuse together to form muscle fibres.
what do the population of cells that are set aside and do not fuse to form fibres become?
satellite cells - stem cells of muscles.
what is sequential process of precursor to muscle cell controlled by?
transcription factors called myogenic factors.
can the muscles of the heart regenerate itself?
no
what happens to your regeneration ability as you get older?
decreases as satellite cells lose the ability to go through the cycle.
what do tendons link
muscles to bones
how does the nerve connection to muscles made?
muscle fibres produce an attractant that attracts the growth of an individual axon from a developing axon.
