Skeletal Muscle Tissue

Which of the following describes the functional characteristic of muscle called elasticity?

After being stretched, muscle tissue can passively recoil and resume its resting length.

Muscle tissue has which of the following functions?

All of the listed responses are correct (Movement Joint stabilization Heat generation)

Skeletal muscle cells have which of the following characteristics?

All of the listed responses are correct. (They are long and cylindrical. Their diameter is 10-100µm. They are multinucleate. They are long and cylindrical and multinucleate.)

Which of the following are important similarities among skeletal, cardiac, and smooth muscle?

All three depend on myofilaments for contraction. Their plasma membrane is called a sarcolemma.

Sarcoplasmic reticulum tubules called "terminal cisterns" form large, perpendicular cross-channels over which junction?

Between each A band in a myofibril and its adjacent I bands

The "sliding filament mechanism" explains which type of muscle contraction?

Concentric contraction

Regarding muscle attachments, which term(s) indicate(s) that the strands of connective tissue are so short that the muscle fascicles appear to attach directly to the bone?

Direct attachments and fleshy attachments

Which of the following describes a fascicle?

Discrete bundles of muscle cells, segregated from the rest of the muscle by a connective tissue sheath

Which of the following describes a skeletal muscle fiber?

Elongated, multinucleate cell that has a striated appearance

The central part of the "A band" of a sarcomere is known as the __________.

H zone

Which portion of the sarcomere creates the light portions of the light-dark pattern of striations seen along the length of a muscle fiber?

I band

During contraction of a sarcomere, what happens to the A band?

It remains the same length.

Which of the following describes the functional characteristic of muscle called extensibility?

Muscle tissue can be stretched by the contraction of an opposing muscle.

How does the sliding filament mechanism result in concentric contraction of skeletal muscle?

Myosin heads of thick filaments attach to thin filaments at both ends of a sarcomere and pull the thin filaments toward the center of the sarcomere.

Which of the following describes functional characteristic of muscle called excitability?

Nerve signals or other factors cause electrical impulses to travel along the cell's sarcolemma, stimulating the cells to contract.

The sarcoplasmic reticulum stores large quantities of which ion?

None of the listed responses is correct (Mg2+ Na+ K+ Cl-)

Which of the following is not a type of muscle tissue?

Nonstriated

What is a motor unit?

One motor neuron and all the muscle fibers it innervates

Which of the following describes an I band sarcomere?

Region of thin filaments only; part of two adjacent sarcomeres

Which skeletal muscle fibers are extremely resistant to fatigue, as long as enough oxygen is present, and deliver prolonged contractions?

Slow oxidative fibers (SO)

Which skeletal muscle fibers are relatively thin, and are red due to their abundant myoglobin content?

Slow oxidative fibers (SO)

Nerve-generated impulses in the sarcolemma are conducted by deep invaginations of the sarcolemma that run between each pair of terminal cisternae. These deep invaginations are called __________.

T tubules

Which of the following describes the events that occur during a muscle contraction of Z discs?

These structures move closer together, causing the sarcomere to shorten.

Which of the following describes the functional characteristic of muscle called contractility?

When muscle cells shorten, they generate a strong pulling force.

During contraction, which of the following occur(s) in a sarcomere?

Z discs move closer together and the lengths of the I bands and the H zone decrease.

Titin is a protein that does all of the following except ____________.

aiding in diffusion of acetylcholine across the synaptic cleft

T tubules ____________.

are deep invaginations of the sarcolemma, and conduct impulses into the deepest region of muscle fibers

Endomysium, perimysium, and epimysium __________.

are each continuous with tendons and are the connective tissue sheaths around skeletal muscle fibers, muscle fascicles, and whole muscles, respectively

Slow oxidative muscle fibers ____________.

are prevalent in postural muscles of the back, and have abundant myoglobin and numerous mitochondria

Muscles may change due to exercise in all the following ways, except ____________.

by increasing in number through dividing mitoticallyx

After being stretched, muscle tissue can recoil passively and resume its resting length. This is known as __________.

elasticity

An "overcoat" of dense, irregular connective tissue surrounding the whole skeletal muscle, and sometimes blending with the deep fascia, is known as __________.

epimysium

The functional characteristic of muscles that allows electrical impulses to travel along the cells' sarcolemma, leading to contraction, is __________.

excitability

In muscle tissue, the characteristic that is defined as "the ability to be stretched by contraction of an antagonist (opposing muscle)" is known as __________.

extensibility

Another name for muscle cells is __________.

muscle fibers

In general, each skeletal muscle is supplied by __________.

one nerve, one artery, and one or more veins

In muscle fibers, fascicles are surrounded by a layer of fibrous connective tissue called __________.

perimysium

Myofilaments are ____________.

protein filaments that are responsible for shortening muscle cells

In a sarcomere, the I band is ____________.

region containing only thin filaments

Which protein is a springlike molecule in sarcomeres that prevents overstretching, extending in a sarcomere from the Z disc to a filament and running within the filament to attach to the M line?

titin