Sliding Filament Mechanism Flashcards
What is the actual mechanism that defines muscle contraction?
Sliding Filament Mechanism
What is a muscle made up of?
Muscle Fibers
Within a muscle, muscle fibers are bundled together into groups called?
Fascicles
What is each muscle fiber filled with?
Myofibrils
Myofibrils run long longitudinally within the muscle fiber and are composed of what filaments?
Sarcomeres
What are sarcomeres composed of?
Thin and thick filaments
Is actin thin or thick filaments?
Thin
Is myosin thin or thick filaments?
What does myosin contain?
Thick
Projection called heads
When a stimulus from the nervous system is sent to the muscle, binding sites on the 1._____ filaments become exposed and the 2._____ heads attach onto them, creating 3._____?
- Actin
- Myosin
- Cross Bridges
Myosin heads attempt to bend in toward the center of the sarcomere, creating pulling force on the ____ filaments?
actin filaments
If the pulling force is sufficiently strong, the 1._____ filaments will be pulled in toward the center of the 2._____, sliding along the 3._____ filament, hence the name 4._______?
- Actin
- Myosin
- Sarcomeres
- Sliding Filament Mechanism
Whatever happens to one sarcomere happens to?
All sarcomeres
If the sum of these forces is GREATER than the resistance to shortening, the actin filaments will be pulled in (toward or away) the center of the sarcomere?
Toward
If the sum of these forces is LESS than the resistance to shortening, the actin filaments will be pulled (toward or away) from the center of the sarcomere?
Away
If the sum of the forces of the myosin heads is equal to the resistance force, what will not move?
Actin Filaments
