Muscle Contraction

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 is the function of acetylcholine?

• ACh binds to receptors on the sarcolemma and opens ion channels

• ACh binds to receptors on the sarcolemma and closes ion channels

• ACh binds to ion channels and open them

• ACh binds to ion channels and closes them

Calcium inside the muscle cell binds to which filament, causing a shape change and revealing the active sites.

• Actin

• Myosin

• Troponin

• Tropomyosin

What binds to the active site on actin?

• Actin

• Myosin

• Troponin

• Tropomyosin

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

How do the actin filaments "slide"?

• With the help of acetylcholine

• With the help of ADP

• With the help of ATP

• With the help of calcium

When is ATP needed?

• When actin slides

• When myosin heads bind to actin

• When myosin heads release from actin

• When myosin slides

After the muscle is no longer stimulated, what occurs first

• Acetylcholinesterase is released and removes ACh

• The muscle continues to contract for a few more minutes

• Enzymes break down calcium ions

• The ion channels pump sodium back out of the cell and potassium back into the cell

Which ways do muscles get their energy from?

• Creatine Phosphate

• Anaerobic Respiration

• Kreb Cycle

• Aerobic Respiration

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

What is the most basic level of the muscular structure?

• Sarcolemma

• Sarcomeres

• Fibers

• fascicles