What organelle wraps and surrounds the myofibril and stores calcium?

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.

One neuron and all the skeletal muscles it stimulates is known as a ________.

Striated involuntary muscle tissue found in the heart is ________.

What is covered by the endomysium?

The plasma membrane of a skeletal muscle cell is called the ________.

What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue?

Which of the following is NOT a function of the muscular system?

A sarcomere is ________.

Which one of the following is composed mostly of the protein myosin?

The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.

Cardiac muscle fibers are joined by special gap junctions called intercalated discs; these discs allow heart activity to be closely coordinated.

Smooth muscles stabilize joints of the skeleton.

The formation of cross bridges requires both calcium ions and ATP.

The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium. 

Cardiac and skeletal muscle both possess striations. 

The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.

Depolarization of a skeletal muscle cell leads to the opening of more channels that only allow potassium entry. 

Voluntary muscle tissue

A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates.

Muscle tissue found only in the heart

Muscle tissue that activates arrector pili muscles to stand hairs on end

The striations seen in skeletal muscle are actually alternating dark A and light I bands. 

Muscle tissue that dilates and constricts the pupils of our eyes

Muscle tissue composed of branching cells and intercalated discs

Performs very slow, sometimes rhythmic, contractions

Muscle tissue that maintains posture, body position, and stabilizes joints

Specific neurotransmitter that stimulates skeletal muscle cells

Chemical that enters a muscle cell upon excitation

Muscle tissue that is multinucleate

Gap between the axon terminals and the plasma membrane of a neighboring muscle cell

Electrical current that travels the length of the sarcolemma that results in the contraction of the muscle fiber

Enzyme that breaks down acetylcholine (ACh)

During skeletal muscle contraction, to what do myosin heads bind?

The movement of a limb toward the body midline

Type of movement that decreases the angle of the joint

Type of movement that allows you to carry a soup bowl

The sarcoplasmic reticulum stores this chemical

The movement of a bone around its longitudinal axis

The movement of a limb away from the body midline

Type of movement that turns the sole of the foot medially

What enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber?

What must rush into a muscle cell to promote its depolarization?

Why are calcium ions necessary for skeletal muscle contraction?

The mechanical force of contraction is generated by ________.

What is acetylcholine?

The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the ________.