10.1-10.3 Mastering

What structures make up a triad?

Two terminal cisternae and a T tubule

The connective tissue fibers of the epimysium, perimysium, and endomysium extend beyond the skeletal muscle cells to form a bundle of connective tissue that joins the muscle cells to a bone. This bundle is called a(n)

Tendon

When would we use the contractile proteins in our skeletal muscle cells to provide energy?

When our diet contains too few proteins or calories

Which of the following is the dark band seen on myofibrils?

A Band

Which of the following is NOT found in the endomysium?

All of these are present in the endomysium.

Which of the following is NOT found in a thin filament?

Myosin

The perimysium surrounds a bundle of muscle fibers called a __________.

fascicle

Voluntary control over swallowing, defecation, and urination is provided by muscles that __________.

guard entrances and exits

The connective tissue layer that surrounds a bundle of skeletal muscle fibers is called __________.

perimysium

Myofibrils are formed as a result of repeating functional units called __________.

sarcomeres

Where is the site of calcium storage in the skeletal muscle fibers?

sarcoplasmic reticulum

Which type of muscle tissue causes contraction of the urinary bladder, forcing urine out of the body?

smooth muscle tissue

Which structure in a muscle fiber or muscle cell is continuous with the sarcolemma and carries the signal to contract deep into the muscle cells?

T tubules

The thin filaments consist of

a pair of F-actin molecules twisted together

A blending of epimysium, perimysium, and endomysium that forms a broad sheet at the end of a muscle is known as __________.

an aponeurosis

The repeating functional units seen in the myofibrils are __________.

Sarcomeres

The thick filaments consist of __________.

About 300 myosin molecules twisted around one another.

What are the three types of muscle tissue?

Cardiac, Smooth and Skeletal

Which connective tissue layer wraps around the entire muscle?

Epimysium

The connective tissue layer that surrounds a single muscle fiber and joins it to other muscle fibers is __________.

Endomysium

The H band contains which structures?

Only myosin in the thick filaments

Which type of tissue is responsible for holding your head upright while you are reading this question?

Skeletal muscle tissue

What structure below is part of the crossbridge?

The myosin head

The sliding of __________ over ___________ causes shortening of skeletal muscle fibers.

actin; myosin

Nerves and blood vessels are contained within the connective tissues of the __________.

epimysium, perimysium, and endomysium

Inherited disorders that produce progressive muscle weakness and deterioration within muscles are called ______________.

muscular dystrophies

One of the distinct features of the skeletal muscle fibers is that they are multinucleated. The multinucleation is the result of the fusion of embryonic cells called __________.

myoblasts

Skeletal muscles develop from the conjoining of a group of embryonic cells knows as _______.

myoblasts

The regulatory protein responsible for elasticity of skeletal muscles is _________.

titin