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
