Chapter 10 Muscle Tissues

Place the organizational level of muscle tissue in order, beginning with the entire muscle and ending with the smallest component.

1. Muscle 2. Fascicle 3. Muscle fiber 4. Myofibril 5. Myofilament

Arrange the following in the proper order in which they occur at the postsynaptic side of a neuromuscular junction.1. Action potential is propagated over the muscle cell membrane.2. Depolarization of the postsynaptic membrane occurs.3. Sodium ions move into muscle cell.

3, 2, 1

The area of the muscle fiber where the actin and myosin myofilaments overlap is the

A band

The source of energy for bonding between myosin and actin is

ATP

Energy is released when

ATP is broken down into ADP and phosphate.

In a relaxed muscle, the ends of the actin filaments overlap.

False

In fully contracted muscles, the actin filaments lie side-by-side.

False

Receptors that bind the neurotransmitter at the postsynaptic cell membrane are voltage-gated.

False

During contraction, the actin myofilaments slide toward the

H zone

Which of the following best describes the role of Ca2+ in muscle contraction?

It binds to troponin, moving tropomyosin, so that myosin heads can bind to actin.

The typical skeletal muscle fiber contains several components that facilitate the production of ATP. Check all that apply.

Mitochondria Myoglobin Glycogen

Which is a characteristic of skeletal muscle from the selections below?

Multinucleated

During contraction of a muscle, calcium ions bind to the

Troponin molecule

The area between the presynaptic nerve cell and the postsynaptic muscle cell is termed the synaptic cleft.

True

The sequence of crossbridge formation and myofilament movement will be repeated as long as calcium ions are present.

True

When crossbridges form and the muscle fibers contract, the actin myofilament slides past the myosin myofilament.

True

During wave summation,

a second stimulus arrives at the muscle before complete relaxation of the first contraction, causing the second contraction to have greater tension than the first one

If you were studying the neurotransmitter released from axon terminals at a neuromuscular junction, you would be studying

acetylcholine.

The primary neurotransmitter at the neuromuscular junction is

acetylcholine.

The bond between the actin and myosin head is broken when

an ATP molecule binds to the myosin head.

The vascular supply to slow oxidative muscle fibers is ______ extensive than that of fast glycolytic muscle fibers.

more

The specialized region of the sarcolemma that has folds and indentations to increase the membrane surface area covered by the synaptic knob is the

motor end plate

The contractile unit of a myofibril is called the

sarcomere

The distance from one Z disk to the next Z disk is called a(n)

sarcomere

An action potential causes calcium ions to diffuse from the ________ into the ________.

sarcoplasmic reticulum; sarcoplasm

The component of a muscle fiber that quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber is called the

transverse tubule (T-tubule).

All of the following are filamentous proteins except

troponin

An action potential causes depolarization of the T-tubule membrane.

true

T-tubules are invaginations of the sarcolemma of a muscle cell

true