Contractions

Which is considered the "main mover"

• Agonist muscle

• Antagonist muscle

• Smooth muscle

• Cardiac muscle

What happens during the power stroke of muscle contraction?

• break down of ATP occurs at the myosin head so that it is ready to pull at actin again

• cross bridges attach to actin filaments and pull them toward the middle of the sarcomere

What ions free the actin strands and allow muscle contraction to occur?

• POTASSIUM

• CALCIUM

• SODIUM

What energy molecule binds to the myosin heads and allows the detachment from actin?

• GLUCOSE

• ADP

• ATP

• CALCIUM

Neurotransmitter that produces an impulse in a muscle cell

• serotnoin

• dopamine

• epinephrine

• acetylcholine

What does the sliding filament model strive to explain?

• OXYGEN DEBT

• MUSCLE FATIGUE

• MUSCLE CONTRACTION

What two proteins prevent the myosin heads from binding to the actin strands?

• troponin 

• globulins

• tropomyosin

• fibrin

when a muscle is unable to contract even through it is still being stimulated

• oxygen debt

• muscle fatigue

• motor units

Microfilaments of actin and myocin in repeating subunits.

• MYOFIBRILS

• Z LINES

• SARCOMERES

• SARCOLEMMA

point of contact between a motor neuron and a skeletal muscle cell

• I band

• neuromuscular junction

• Sarcoplasmic reticulum

• Epimysium