The Muscular System Flashcards
The three muscle tissues types
Skeletal, smooth, cardiac
Skeletal Muscle
Voluntary control, striated appearance.
Attached to bones and is responsible for voluntary movements.
Cardiac Muscle
Involuntary control, striated but with intercalated discs.
Found in the heart, responsible for pumping blood.
Smooth Muscle
Involuntary control, non-striated.
Found in walls of organs and vessels, responsible for involuntary movements like digestion.
Sarcomere
the fundamental unit of muscle that’s responsible for contraction.
Z-discs
Boundary of the sarcomere; anchor thin filaments.
I band
Region with only thin filaments; shortens during contraction.
A band
Region containing the entire length of thick filaments; remains unchanged during contraction.
H zone
Central region of A band with only thick filaments; shortens during contraction.
M line
Middle of the sarcomere; stabilizes thick filaments
Thin Filaments
made of actin
Actin
Actin is the protein that forms the thin filaments and provides the binding sites for myosin during muscle contraction.
Tropomyosin
Tropomyosin is a protein that covers actin’s myosin-binding sites, preventing contraction until activated.
Troponin
Troponin is a protein that binds calcium ions, causing tropomyosin to move and expose actin’s binding sites for myosin.
Thick filaments
Made of myosin
Myosin
Structured with a head, neck and tail. Binds to actin and uses ATP to pull actin filaments toward the center of the sarcomere and contract the muscle
ATP
adenosine triphosphate; energy!!!!!
CA2++
calcium