Muscle Activity: Name:_______________________________________Use your text/lab manual/online resources to answer these questions.Neuromuscular junction (NMJ)—where the motor neurons direct conscious movement, and reflex movement:What is the motor end plate?What is acetylcholine (ACh)? What does it do?What is the role of calcium at the NMJ, and in the sarcomere?Know these terms and how they relate to muscle contraction:Neuromuscular junction (NMJ)SarcomereMyosin (a myofilament)Actin (a myofilament)TropomyosinTroponinATP & calciumWhat is a “cross-bridge”? (Does the power stroke of one cross-bridge produce the contraction of an entire muscle?Briefly describe why contraction of the muscle cell is called “sliding filament theory” (what is sliding?) and what do we mean by “excitation-contraction coupling?” (What is being excited, and what is coupled?)If we need ATP for both contraction and relaxation, how would you explain why rigor mortis appears in a dead person, but then goes away?Sketch a sarcomere, and label thin and thick filaments, Z discs, titin (elastic filaments), M line, H zone, I bands, and A band.Draw a simple sketch showing a relaxed sarcomere, and one that is contracted.When a sarcomere contracts, are the filaments shortening, or is overlap of the filaments occurring?

Muscle Activity: Name:_______________________________________

Use your text/lab manual/online resources to answer these questions.

Neuromuscular junction (NMJ)—where the motor neurons direct conscious movement, and reflex movement:

What is the motor end plate?

What is acetylcholine (ACh)? What does it do?

What is the role of calcium at the NMJ, and in the sarcomere?

Know these terms and how they relate to muscle contraction:

Neuromuscular junction (NMJ)

Sarcomere

Myosin (a myofilament)

Actin (a myofilament)

Tropomyosin

Troponin

ATP & calcium

What is a “cross-bridge”? (Does the power stroke of one cross-bridge produce the contraction of an entire muscle?

Briefly describe why contraction of the muscle cell is called “sliding filament theory” (what is sliding?) and what do we mean by “excitation-contraction coupling?” (What is being excited, and what is coupled?)

If we need ATP for both contraction and relaxation, how would you explain why rigor mortis appears in a dead person, but then goes away?

Sketch a sarcomere, and label thin and thick filaments, Z discs, titin (elastic filaments), M line, H zone, I bands, and A band.

Draw a simple sketch showing a relaxed sarcomere, and one that is contracted.

When a sarcomere contracts, are the filaments shortening, or is overlap of the filaments occurring?