Muscle contraction

​Transmission of impulse at neuromuscular junction

Multiple Choice

What trigger the opening of voltage gated Ca²⁺ channel in the axon terminal?

• Ca²⁺ influx

• Arrival of action potential

• Arrival of presynaptic membrane

• Na⁺ influx

Multiple Choice

Which ion responsible in the fusion of synaptic vesicle with presynaptic neuron?

• Ca²⁺

• Na⁺

• K⁺

• Cl^-

Multiple Choice

Which neurotransmitter involve in muscle contraction?

• Dopamine

• Adrenaline

• Acetylcholine

• NADH

Multiple Choice

What is H zone?

• consist only thick filament

• consist both thick and thin filament overlap

• consist of thin filament

• hold the thick filament

Multiple Choice

What is A band?

• consist only thick filament

• consist both thick and thin filament overlap

• consist of thin filament

• consist only thin filament

Multiple Choice

The functional unit of the muscle cell is the: 

• Sarcomere
• Osteon
• Myofilament
• Muscle fiber

Multiple Choice

Thin filaments in a myofibril are

• Sarcomeres
• Sarcoplasm
• Actin
• Myosin

Multiple Choice

Thick filaments are in a myofibril are

• ATPase
• Sarcoplasmic reticulum
• Actin
• Myosin

​MECHANISM OF MUSCLE CONTRACTION BASED ON

Multiple Choice

Ca2+ will be released from the sarcoplasmic reticulum when

• impulse reaches neuromuscular junction

• impulse transmitted along T tubule

• ATP binds to sarcoplasmic reticulum

• acetyl choline binds to ligand gated ion channels

Multiple Choice

Ca2+ released by sarcoplasmic reticulum will bind to

• Actin

• Troponin

• Myosin

• Tropomyosin

Multiple Choice

Power stroke will occur when

• ATP binds to myosin head

• Myosin head releases ADP and Pi

• Myosin head hydrolyse ATP

• Myosin binds to actin

Multiple Choice

Cross bridges are formed when

• ADP and Pi released from myosin head

• ATP binds to myosin head

• Myosin head hydrolyse ATP

• Tropomyosin binds to myosin binding site

• A human dies

Multiple Choice

____________ attaches to actin to form the cross bridge.

• Troponin

• Tropomyosin

• Myosin

• Calcium