Lecture 10: Muscle Tissue I And II Flashcards
3 types of muscle tissue
-skeletal
-cardiac
-smooth
Muscle fiber definition
-muscle cell
-myocyte
Functions of muscle fibers (3)
Produce force, movement and heat
Muscle fibers are surrounded by
Connective tissue
Sarcoplasm
Cytoplasm in muscle cell
What is contraction
Interaction of myofilaments
2 myofilaments in muscle fibers
Actin and myosin
Actin are __________ filaments
Thin
Myosin are __________ filaments
Thick
How/why do actin and myosin move (general)
-calcium causes conformational change
-actin and myosin move relative to each other (stack)
Which muscle tissue types are striated
Skeletal and cardiac
Which muscle type is non striated
Smooth
2 general Features of skeletal muscle
-larger cell diameter = greater force
-rich blood supply
Is skeletal muscle mononucleated or multinucleated
Multi
Skeletal muscle contains an abundance of
-mitochondria
-glycogen
-myoglobin
Myoglobin vs hemoglobin
Myoglobin has more oxygen
What is skeletal muscle usually attached to
Bone
-sometimes other muscles
Fascia
Connective tissue arranged in a sheet
Fascicle definition
Bundles of muscle fibers
Muscle fiber definition
Myocyte (muscle cell)
Myofibrils definition
Long row of myofilaments
Organization of skeletal muscle (biggest to smallest)
Bone —> muscle —> fascicle —> muscle fiber —> myofibrils
3 layers surrounding skeletal muscle
-epimysium
-peri my sim
-endomysium
Epimysium
Surrounds entire muscle
Perimysium
Surround fascicles
Endomysium
Surrounds muscle cell/myocyte
Epimysium and perimysium are composed of what kind of structural protein
Type 1 collagen
Endomysium is composed of what structural proteins
Other types of collagen (not type 1)
What do striations result from in skeletal muscle
Overlapping myofilament arrangement
What 3 skeletal muscle striations can we see at the level of light microscopy
-A bands
-I bands
-Z disk
A bands appearance
Dark bands
I bands appearance
Light bands
Z disk aka
Z line
Z disk appearance
Dark line in I band
What striations get closer together in skeletal muscle during contraction
Z disks
What 5 skeletal muscle striations are visible at TEM
-I band
-A band
-Z disk
-H band
-M line
Sarcomere definition
Z disk to Z disk