Chapter Questions
What are the characteristics of the three types of muscles in the human body? Where is each type found? (page 254 )
Give an example to show that skeletal muscles work in antagonistic pairs. Explain. (page 255)
What criteria are used to name muscles? Give an example of each one. (pages 256,258 )
What are the functions of a muscle fiber's components? (pages $258-60)$
Describe the sliding filament model of muscle contraction within a sarcomere. Begin with the nerve impulse and end with the relaxation of the muscle. (pages $261-63$ )
What are the four possible energy sources for a muscle and the three sources of ATP for muscle contraction? (pages $263-64)$
Compare fast- and slow-twitch muscle fibers. (pages $264-66$ )
What are some common muscular disorders and some more serious muscular diseases? (pages $268-69$ )
How does the muscular system help maintain homeostasis? (pages $269,271)$
Impulses that move down the T system of a muscle fiber most directly causea. movement of tropomyosin.b. attachment of the cross-bridges to myosin.c. release of $\mathrm{Ca}^{2+}$ from the sarcoplasmic reticulum.d. splitting of ATP.
Which of the following statements about cross-bridges is false?a. They are composed of myosin.b. They bind to ATP after they detach from actin.c. They contain an ATPase.d. They split ATP before they attach to actin.
Which statement about sarcomere contraction is incorrect?a. The A bands shorten.b. The H zones shorten.c. The I bands shorten.d. The sarcomeres shorten.
Which of the following muscles would have motor units with the lowest innervation ratio?a. leg musclesb. arm musclesc. muscles that move the fingersd. muscles of the trunk
The thick filaments of a muscle fiber are made up ofa. actin.b. troponin.c. fascia.d. myosin.
As ADP and ? are released from a myosin head,a. actin filaments move toward the H zone.b. myosin cross-bridges pull the thin filaments.c. a sarcomere shortens.d. Only a and care correct.e. All of these are correct.
Which of these is a direct source of energy for muscle contraction?a. ATPb. creatine phosphatec. lactic acidd. glycogene. Both a and b are correct.
When muscles contract,a. sarcomeres increase in length.b. actin breaks down ATP.c. myosin slides past actin.d. the H zone disappears.e. calcium is taken up by the sarcoplasmic reticulum.
Nervous stimulation of musclesa. occurs at a neuromuscular junction.b. results in an impulse that travels down the T system.c. causes calcium to be released from expanded regions of the sarcoplasmic reticulum.d. All of these are correct.
In a muscle fiber,a. the sarcolemma is connective tissue holding the myofibrils together.b. the $\mathrm{T}$ system causes release of $\mathrm{Ca}^{2+}$ from the sarcoplasmic reticulum.c. both actin and myosin filaments have cross-bridges.d. there is no endoplasmic reticulum.e. All of these are correct.
To increase the force of muscle contraction,a. individual muscle cells have to contract with greater force.b. motor units have to contract with greater force.c. motor units need to be recruited.d. All of these are correct.e. None of these is correct.
Lack of calcium in muscles willa. result in no contraction.b. cause weak contraction.c. cause strong contraction.d. will have no effecte. None of these is correct.
Which of these energy relationships are mismatched?a. creatine phosphate-anaerobicb. cellular respiration-aerobicc. fermentation-anaerobicd. oxygen debt-anaerobice. All of these are properly matched.
During muscle contraction,a. ATP is hydrolyzed when the myosin head is unattached.b. ADP and ? are released as the myosin head attaches to actin.c. ADP and ? release causes the head to change position and actin filaments to move.d. release of ATP causes the myosin head to return to resting position.
Proper functioning of a neuromuscular junction requires thea. presence of acetylcholine.b. presence of a synaptic cleft.c. presence of a motor terminal.d. sarcolemma of a muscle cell.e. All of these are correct.
Match each muscle to a region of the body in the key.a. neck and backb. abdomenc. armd. thighBiceps femoris
Match each muscle to a region of the body in the key.a. neck and backb. abdomenc. armd. thighTrapezius
Match each muscle to a region of the body in the key.a. neck and backb. abdomenc. armd. thighRectus abdominis
Match each muscle to a region of the body in the key.a. neck and backb. abdomenc. armd. thighTriceps brachii
Match each function to a muscle of the buttocks and legs in the key.a. tibialis anteriorb. gluteus maximusc. biceps femorisd. gastrocnemiusBends leg at knee and extends thigh back
Match each function to a muscle of the buttocks and legs in the key.a. tibialis anteriorb. gluteus maximusc. biceps femorisd. gastrocnemiusBends ankle so that foot is upward
Match each function to a muscle of the buttocks and legs in the key.a. tibialis anteriorb. gluteus maximusc. biceps femorisd. gastrocnemiusBends leg at knee and bends sole of foot
Match each function to a muscle of the buttocks and legs in the key.a. tibialis anteriorb. gluteus maximusc. biceps femorisd. gastrocnemiusExtends thigh back
Match each function to a muscle of the head and neck in the key.a. trapeziusb arhicularis aculic. masseterA chewing muscle
Match each function to a muscle of the head and neck in the key.a. trapeziusb arhicularis aculic. masseterMoves head and scapula
Match each function to a muscle of the head and neck in the key.a. trapeziusb arhicularis aculic. masseterCloses eye
Match the functions to a muscle of the upper limb and trunk in the key.a. external obliqueb. triceps brachic. pectoralis majorCompresses abdomen
Match the functions to a muscle of the upper limb and trunk in the key.a. external obliqueb. triceps brachic. pectoralis majorBrings arm across chest
Match the functions to a muscle of the upper limb and trunk in the key.a. external obliqueb. triceps brachic. pectoralis majorStraightens forearm at elbow
Match each function to a muscle of the lower limb in the key.a. adductor longusb. quadriceps femorisc. sartoriusStraightens leg at knee
Match each function to a muscle of the lower limb in the key.a. adductor longusb. quadriceps femorisc. sartoriusMoves thigh toward the body
Match each function to a muscle of the lower limb in the key.a. adductor longusb. quadriceps femorisc. sartoriusLateral rotates thigh
Label this diagram of a muscle fiber, using these terms: myofibril, T tubule, sarcomere, sarcolemma, sarcoplasmic reticulum, $Z$ line.