Muscular System

Which ion is depicted as playing a crucial role in muscle contraction in the diagram?

• Sodium

• Potassium

• Calcium

• Magnesium

Skeletal muscle is the only type of muscle that is under voluntary control. What does this mean?

• They move automatically.

• Our subconscious tells us when to move them.

• They move when we consciously decide to move them.

What role does the muscular system play in joint stability?

• It reinforces the connections of bones

• It generates heat

• It maintains posture

• It produces movement

Which characteristic of muscle tissue is associated with a response to a motor neuron or hormone?

• Extensibility

• Excitability

• Elasticity

• Contractability

Which muscle type is not consciously controlled?

• Skeletal muscle

• Cardiac muscle

• Voluntary muscle

• None of the above

What type of muscle provides slower motion?

• Skeletal muscle

• Cardiac and smooth muscle

• Fast-twitch muscle

• None of the above

What is the function of tropomyosin?

• It binds calcium ions.

• It blocks myosin binding sites on actin.

• It hydrolyzes ATP.

• It releases ADP.

What triggers the release of calcium ions in the muscle contraction cycle?

• ATP binding to myosin

• Nerve impulse

• ADP release

• Troponin binding

What does the myosin filament pull on to shorten a sarcomere?

• Actin filament

• Calcium ions

• ATP molecules

• Muscle fiber

What is the result of the sliding filament theory?

• Muscle contraction

• Muscle relaxation

• Muscle elongation

• Muscle fatigue