Muscular System

Which muscle closes and protrudes the lips?

Which muscle is shown in the picture?

What is the first step that must happen at a neuromuscular junction?

• Calcium channels open and calcium diffuses into the terminal.

• Action potential arrives at axon terminal of motor neuron.

• ACh diffuses and binds to its receptors.

• Action potential propagates along sarcolemma.

What is indicated by the letter D?

• ACh receptors

• Axon

• Calcium channels

• Vesicles

Muscles are made of thick and thin filaments. What is the name of the thick filaments?

• Actin

• Myosin

Which of the following about muscles are true? (you may select more than one)

• long and cylindrical

• contain a single nucleus

• striated

• enclosed in a sarcolemma

Which muscle is shown in the picture?

Which muscle extends the forearm?

Which movement causes a limb to move away from the midline of the body?

• Flexion

• Extension

• Adduction

• Abduction

Which property of muscles is defined as the ability to be stretched?