Essentials of Anatomy and Physiology

1. Name the organ systems directly involved in
   movement, and for each state how they are
   involved. (p. 138)


2. State the function of tendons. Name the part of a
   muscle and a bone to which a tendon is attached.
   (p. 138)


3. State the term for: (pp. 138–139)
   a. Muscles with the same function
   b. Muscles with opposite functions
   c. The muscle that does most of the work in a
   movement


4. Explain why antagonistic muscle arrangements
   are necessary. Give two examples. (p. 138)


5. State three reasons why good muscle tone is
   important. (p. 140)


6. Explain why muscle sense is important. Name the
   receptors involved and state what they detect.
   (p. 141)


7. With respect to muscle contraction, state the
   functions of the cerebellum and the frontal lobes
   of the cerebrum. (p. 140)
   8. Name the direct energy source for muscle con-
   traction. Name the two secondary energy sources.
   Which of these is more abundant? (p. 141)
   9. State the simple equation of cell respiration and
   what happens to each of the products of this reac-
   tion. (p. 142)


8. Name the two sources of oxygen for muscle
   fibers. State what the two proteins have in com-
   mon. (p. 142)


9. Explain what is meant by oxygen debt. What is
   needed to correct oxygen debt, and where does it
   come from? (p. 142)


10. Name these parts of the neuromuscular junction:
    (p. 142)
    a. The membrane of the muscle fiber
    b. The end of the motor neuron
    c. The space between neuron and muscle cell
    State the locations of acetylcholine and cholin-
    esterase.


11. Name the contracting proteins of sarcomeres, and
    describe their locations in a sarcomere. Where is
    the sarcoplasmic reticulum and what does it con-
    tain? (p. 142)

The Muscular System 161

REVIEW QUESTIONS

outside and a () charge inside. Naions are more

abundant outside the cell and Kions are more

abundant inside the cell. The Naand Kpumps

maintain these relative concentrations on either

side of the sarcolemma (see Table 7–1 and Fig.

7–4).

5. Depolarization: This process is started by a nerve
   impulse. Acetylcholine released by the axon termi-
   nal makes the sarcolemma very permeable to Na
   ions, which enter the cell and cause a reversal of
   charges to () outside and () inside. The depo-
   larization spreads along the entire sarcolemma and
   initiates the contraction process. Folds of the sar-
   colemma called T tubules carry the depolarization
   into the interior of the muscle cell.

Contraction—the sliding filament mecha-
nism (see Fig. 7–5)

1. Depolarization stimulates a sequence of events
   that enables myosin filaments to pull the actin fila-

ments to the center of the sarcomere, which short-

ens.

2. All of the sarcomeres in a muscle fiber contract in
   response to a nerve impulse; the entire cell con-
   tracts.


3. Tetanus is a sustained contraction brought about by
   continuous nerve impulses; all our movements
   involve tetanus.


4. Paralysis: Muscles that do not receive nerve
   impulses are unable to contract and will atrophy.
   Paralysis may be the result of nerve damage, spinal
   cord damage, or brain damage.

Responses to Exercise—maintaining homeo-

stasis

See section in chapter and Fig. 7–6.

Major Muscles

See Tables 7–2 through 7–7 and Figs. 7–7 through

7–13.