Exam 12: Muscles

Groups of adjacent fibers bundled together into units are called ________.These bundles are surrounded by the proteins ________ and elastin as well as ________ that deliver nutrients to the muscle cells.

The function of transverse tubules is to

Explain the events leading up to a skeletal muscle twitch, starting with the arrival of neurotransmitter in the neuromuscular junction.

Briefly compare and contrast the structure and behavior of cardiac, smooth, and skeletal muscles.

Match the structures with the accurate description. -highly organized bundles of contractile proteins within a skeletal muscle cell

Motor units that control skeletal muscles involved with fine motor movements (eye muscles or the hands)have ________ muscle fibers than motor units that control more gross movements (gastrocnemius muscle of the lower leg).

In order to contract and relax, muscle cells require energy in the form of ________.The immediate backup energy source is ________ that requires the enzyme ________.

When comparing complete tetanus with unfused (incomplete)tetanus, which is True?

You and your lab partner use a living nerve and muscle preparation to study muscle contraction.When you stimulate the nerve electrically, the muscle contracts; why? When you turn off the stimulator but add a high concentration of caffeine to the fluid surrounding the tissues, the muscle contracts; why (speculate on possible sites/mechanisms of action)? When curare (which blocks neuromuscular transmission)is added with caffeine, contraction occurs; why (speculate, and how does this alter your previous answer)? Can you identify a single site of action from this information? If not, what additional experiment would narrow your choices?

A construction worker entered the emergency room after an accident in which his leg was crushed by falling beams.A color of the urine sample is noticeably reddish brown.Assuming that color is related to the accident, what molecule could have been released from the damaged muscle cells that colored the urine? What is the function of this molecule?

In order for the bicep muscle to shorten, the force applied by the muscle must be ________ the load applied at the hand.

Match from the following list. -The lightest color bands of the sarcomere, comprised only of thin filaments.

The speed with which force is developed by skeletal muscles is determined by the

In fast-twitch oxidative-glycolytic fibers, their rapid increases in force rely on the ________ activity where rapid relaxation requires ________ activity.

Smooth muscle cells lack which protein(s)?

Factors playing a role in fatigue can be classified into two categories.Define those two categories and provide an example of each.

A(n)________ contraction describes the opening of stretch-activated channels in smooth muscle cells in response to a distortion of the cell membrane that is commonly observed in ________.

Striated muscles are so-called because of a repeating pattern of light and dark bands.One repeating unit of the banding pattern is called a

Skeletal muscle fibers with the greatest endurance rely on ________ for energy.

The gap junctions in cardiac muscle are part of specialized cell junctions that are localized to the ________.