Muscle Contractions

Skeletal Muscle Contraction

by Blake Pierce

Multiple Choice

Which forms the thick filament of a sarcomere?

• Actin

• Myosin

• Troponin

• Tropomyosin

Multiple Select

Which of the following make up the thin filaments of a sarcomere?

• Actin

• Myosin

• Troponin

• Tropomyosin

Multiple Choice

According to the sliding filament model , during muscle contraction

• a myosin head attaches to a binding site on the actin

• an actin head attaches to a binding site on the myosin

Multiple Choice

Which of the following the muscle fiber to shorten?

• The actin pulls on the myosin making it shorter

• The mysoin acts on the actin making it shorter

• Sarcomeres shortening at the same time

• all of these are correct

Multiple Select

Which of the following changes in the sarcomere during contraction?

• The A band gets shorter

• The I band gets shorter

• The Z lines get closer together

• The H zone gets smaller

Multiple Choice

Which of the following is the neurotransmitter for muscle contraction at the neuromuscular junction?

• Acetylcholine

• acetylcholin-esterase

• calcium

• Adenosine Triphosphate

Multiple Choice

What is the substance released that interacts with the proteins on the actin filaments?

• acetlycholine

• acetylcholin-esterase

• calcium

• Adenosine Triphosphate

Multiple Choice

What structure releases calcium to the cytosol of the muscle fiber?

• Sarcolemma

• Sarcoplasmic reticulum

• Synaptic vesicles

• Sarcomere

Multiple Select

The high concentration of calcium in the sarcoplasm interacts with which 2 proteins to expose myosin binding sites?

• Actin

• Troponin

• Tropomyocin

• Myosin

Multiple Choice

What substance is necessary for cross-bridges to form and pull on the actin filaments?

• Acetylcholine

• Acetylcholin-esterase

• Calcium

• Adenosine Triphosphate

Multiple Choice

What enzyme is necessary in the motor end plate to relax the muscle following contraction?

• Acetylcholine

• Acetylcholin-esterase

• Calcium

• Adenosine Triphosphate

Multiple Choice

What substance binds to the myosin heads, breaking the linkage between the myosin and actin?

• Acetylcholine

• Acetylcholin-esterase

• Calcium

• Adenosine Triphosphate