Sarcomere Structure Flashcards
What is whole muscle made up of?
Bundles of fascicle
What is each fascicle made up of?
Series of fibres
What is each muscle fibre made up of?
Myofibrils
What is each myofibril made up of?
Repeating units (sacromeres)
What cells does muscle start developing from?
Myosatellite cells - mesenchymal cells in each myotome
What do myosatellite/mesenchymal cells give rise to?
yoblasts - immature muscle cells
What are my oblasts like?
Mononuclear
Skeletal muscle precursors
What do myoblasts mature into?
Myocytes
What are myocytes like?
Multinucleated cells
Muscle development:
Myosatellite cells -> myoblasts -> myocytes
What do myotubes form?
Myofilaments by synthesising myosin and actin (contractile proteins)
What type of process is the formation of myofilaments?
Regulated process of differentiation
What inhibits formation of myofilaments?
Myostatin
How are sacromeres organised?
Within skeletal and cardiac muscle
Apparently of sacromeres:
Striped appearance - striated
What is a sacromere?
Portion of myofibril between two successive z discs
What’s the difference from one z disc to another z disc called?
One sarcomere
What do contractile proteins consist of?
Thin filaments (actins)
Thick filaments (myosin)
What does I band represent?
Actin filaments
What does A band represent?
Myosin filaments
What’s a H band?
Gap between successive actin filaments
What makes up a Z-disc?
a-actinin
What is a-actinin?
Actin-binding protein
Why is a-actinin important?
Binds ends of thin filaments to Z-discs