Muscle Contraction Quiz

What initiates the muscle contraction process?

• A signal from the brain

• A signal from the heart

• A signal from the lungs

• A signal from the stomach

What neurotransmitter is released at the neuromuscular junction?

• GABA

• Acetylcholine

• Serotonin

• Dopamine

What happens when acetylcholine binds to its receptors on the muscle fiber?

• Chloride ions enter the muscle fiber

• Calcium ions enter the muscle fiber

• Sodium ions enter the muscle fiber

• Potassium ions enter the muscle fiber

What is the role of calcium ions in muscle contraction?

• They bind to actin

• They bind to tropomyosin

• They bind to troponin

• They bind to myosin

What structural change occurs when calcium binds to troponin?

• Troponin is removed from the actin filament

• Troponin covers the actin filament

• Tropomyosin is removed from the myosin binding site

• Tropomyosin covers the myosin binding site