movement and muscles part 3 Flashcards
Contractile filament
thick filament is composed of what?
polymer of myosin
approx 300 myosin 2 hexamer
Contractile filament
what is thin filament composed of?
polymer of alpha- actin
Contractile filament
what are the ends of thin filament capped in?
tropomodulin
Contractile filament
what is thin filament stabalized by?
Capz
The two main types of muscle are based on what?
smooth and striated and are based on the arrangement of actin and myosin
Striated muscles characteristics?
used for movement
skeletal/cardiac
actin/myosin in parallel
smooth muscles characteristics?
used for digestion
vasoconstriction
actin/myosin not in parallel
Where are myofibrils found?
in skeletal muscles
Where are cardiomyocytes found?
in the cardiac muscles
In striated muscles how are the filaments arranged?
thick and thin filaments arranged in sarcomeres
repeated in parallel and series
What are Z-disks?
forms boarder of each sarcomere
thin filament is attached to z disk
titin attached
capz
Where is capz located and what does it do?
attached to z disk and (+) end of the actin and will prevent polymerization and depolarization
What is the A-band?
anisotropic band
middle region of sarcomere occupied just with thick filament
What is the I-band?
(isotropic band)
locatedon either side of the Z-disk
occupied by thin filament
What is the M-line?
located where the myosin 2 filaments join together
how many times do thick and thin filament overlap in each sarcomere?
2x
each thick filament is surrounded by how many thin ones?
six
What is Nebulin?
stabalizing protein that runs along the length of thin filament
What is titin?
secures the thin filament to the Z-disk
keeps the thick filament centered in sarcomere
very large and acts like a spring
What is isotonic contraction?
some load but length of muscle changes ex. moving flexed limb
What is isometric contraction?
contract but do not change in distance
ex. ab muscles, change tension but do not change in distance
change load on muscles
