Sliding Filament Review

Contractile unit of a muscle.

• sarcomere

• motor unit

• fascicle

• myofibril

Thick filaments are in a myofibril are

• ATPase

• Sarcoplasmic reticulum

• Actin

• Myosin

Thin filaments in a myofibril are

• Sarcomeres

• Sarcoplasm

• Actin

• Myosin

The energy needed to perform a muscle contraction comes directly from

• ATP

• Oxygen

• Glucose

• Calcium

What must occur first before a muscle can contract?

• An action potential must develop as energy/nutrients is gained from the digestive system

• An action potential must travel to the muscle through the circulatory system

• An action potential must enter the body through the respiratory system

• An action potential must be sent through neurons in the nervous system

What neurotransmitter is used at the neuromuscular junction that sends a signal from the motor neuron to the skeletal muscle?

• Glutamate

• Acetylcholine

• Norepinephrine

• Dopamine

What happens when the action potential reaches the axon terminal of a motor neuron?

• Voltage-gated channels open, releasing sodium

• Voltage-gated channels open, releasing acetylcholinesterase

• Voltage-gated channels open, releasing acetylcholine

• Voltage-gated channels open, releasing calcium

What is a cross-bridge?

• When troponin and tropomyosin undergo a shape change

• When the active site of actin is revealed

• When the myosin heads bind to the actin active site

• When the actin filaments slide past the myosin filaments

When a myosin head engages with the active site on the other filament, this is known as a(n)

• Sarcomere

• Z-line

• cross-bridge (power stroke)

• M line

This image shows a ________?

• Sarcomere

• Fascicle

• Neuromuscular Juntion

• Prime mover