Hiearchy of muscle structure Flashcards
what is the hiearchy of muscle from smallest to largest?
- myofilament
2.myofibril
3.Muscle cell/fiber
4.fascicle
5.whole muscle
What is a myofilament?
an individual protein that provide structure to skeletal muscle and help with CONTRACTION and regulating contraction
actin is a ____ fiament
thin
what is actin?
a contractile protein that binds with myosin to generate force
what is tropomyosin?
a regulatary protein that wraps around actin
What is troponin?
a regulatory protein that binds to actin and serves as a Ca+ receptor and pushes tropomyosin OFF active binding sites changing shape
What are the three types of troponin?
- troponin T (TnT)
- Troponin I (TnI)
3.Troponin C (tnC)
What does troponin T (TnT) do?
binds to tropomyosin to lock actin and tropomyosin together
what does troponin I (TnI) do?
binds to actin to lock actin and tropomyosin together
what does troponin C do?
binds with Ca+ and moves tropomyosin OFF active binding sites which changes shape
What are the thin filaments?
Actin
tropomyosin
troponin
what are the thick filaments?
myosin
myofibril
muscle cell/fiber
What is myosin?
-main component of thick filaments
-CONTRACTILE protein thats binds with actin to generate force
For 1 myosin there are ____ actin
explanation: for evrery ONE thick filament, there are SIX thick filaments
what do structural filaments do?
help with allignment of thick and thin fillaments
what is a myofibril?
a bundle of myofilaments
The ____ is the functional unit of a myofibril
sacromere
Part of a sacromere:
Z-disk/line
the edge
Part of a sacromere:
M-line
the center
part of a sacromere:
I band
JUST actin
part of a sacromere:
H-zone
just Myosin
part of a sacromere:
A band
myosin and actin overlap
which band gets smaller when a muscle contracts?
I band gets smaller at contraction
which band gets larger when muscle contracts?
A band get larger
Part of a mucle cell:
Sarcolemma
the muscle cell plasma membrane
Part of a mucle cell:
Satellite cell
other type of muscle cell that regulates growth and mucular adaptations
Part of a mucle cell:
transverse tubules
highways for APs that run inward from sarcloemma to myofibrils
Part of a mucle cell:
Sarcoplasmic reticulum (SR)
network of tube that surrond myofibrils and are the STOREHOUSE for calcium
Part of a mucle cell:
Terminal cisternae
enlarged portions of the SR for Calcium (Ca+) strorage
Part of a mucle cell:
Mitochondria
factories that produce ATP using O2
Part of a mucle cell:
Nuclei
control center for muscle cell/fiber
What is a fascicle made up of?
a bundle of mucle cells/fibers
what is a whole muscle made up of?
a bundle of fascicles
How does tropomyosin act in a relaxed muscle?
tropomyosin blocks active binding sites on actin which prevents myosin from binding with actin
How does tropmyosin act in presence of Calcium?
it gets pushed off active binding sites so myosin and actin can bind which then generates muscle force
collagen, elastin, titin, nebulin, myomesin, and dystrophin are all…
structural filaments
Where is the mitochondria is a muscle cell?
in the muscle sarcoplasm
