Ch10

Question 1

The different types of muscle tissue differ from each other by

Microscopic anatomy
Location
Type of control 
Both microscopic and location
All of these

Answer 1

All of these

Question 2

Which of the following is NOT a major function of muscle tissue?

Moving blood through the body
Generating heat through contractions
Stabilizing the movement of joints 
Promoting movement of body structures
Production of vitamins

Answer 2

Production of vitamins

Question 3

Which property of muscle gives it the ability to stretch without damage?

Electrical excitability 
Contractility
Extensibility 
Elasticity
Thermogenesis

Answer 3

Extensibility

Question 4

In an isometric contraction the muscle develops but does not….

Lengthen
Widen
Does not expend energy
Conduct electrical current
Exhibit elasticity

Answer 4

Lengthen

Question 5

This is the outermost layer of connective tissue surrounding the skeletal muscle

Tendon
Ligament
Endomysium
Epimysium
Perimysium

Answer 5

Epimnysium

Question 6

What type of tendon is formed when connective tissue elements of skeletal muscle extend as a broad flat layer?

Perimysium
Deep fascia
Fascicle
Aponeurosis
Endomysium

Answer 6

Aponeurosis

Question 7

After the fusion of myoblasts, the muscle fiber are thread-like structures called..

Myofibrils
Myoglobin 
Mitochondria
Z discs
M lines

Answer 7

Myofibrils

Question 8

Release of calcium from these structures triggers skeletal muscle contractions

Myofibrils 
Mitochondria
Terminal cisterns of sarcoplasmic reticulum 
T-tubules
None of these are correct

Answer 8

Terminal cisterns of sarcoplasmic reticulum

Question 9

Which of the following regions of a sarcomere contain thin filaments?

I band
A band 
H zone
Both I band and A band
All of these are correct

Answer 9

Both I band and A band

Question 10

Which of the following regions of the sarcomere contain thick filaments?

A zone of overlap
A band
H zone
Both A band and H zone
All of these answer choices are correct

Answer 10

All of these answer choices are correct

Question 11

Myofibrils contain

Contractile
Regulatory proteins 
Structural proteins
All of these
None of these

Answer 11

All of these

Question 12

Which of the following functions as a motor protein in all three types of muscle tissue?

Actin
Myosin
Troponin
Titin
Tropomyosin

Answer 12

Myosin

Question 13

What regulatory proteins can be found in the thin filaments of skeletal muscle fibers?

Troponin and titin
Tropomyosin and troponin
Myosin and titin
Titin and tropomyosin

Answer 13

Tropomyosin and troponin

Question 14

Which of the regions of a sarcomere contain titin?

The A band only
The H zone only
The zone of overlap only
From M to Z disc
The I band only

Answer 14

From M line to Z disc

Question 15

19) Which of the following proteins is used to reinforce the sarcolemma and to help transmit the tension generated by the sarcomeres to the tendons?

a) troponin
b) tropomyosin
c) myosin
d) actin
e) dystrophin

Answer 15

dystrophin

Question 16

20) During muscle contraction by the sliding filament mechanism, thin filaments are pulled towards the

a) Z disc.
b) H zone.
c) M line.
d) A band.
e) I band.

Answer 16

M line

Question 17

21) Calcium ions are released from the sarcoplasmic reticulum into the cytosol

a) at the beginning of a contraction.
b) in response to acetylcholine binding to Ca2+ release channels.
c) by active transport using Ca2+ pumps in the SR membrane.
d) after the contraction ends.
e) All of these answers are correct.

Answer 17

a) at the beginning of a contraction

Question 18

22) What energizes the myosin head?

a) the actin filaments
b) calcium ions
c) potassium ions
d) ATP hydrolysis reaction
e) ADP synthesis

Answer 18

d) ATP hydrolysis reaction

Question 19

23) Skeletal muscle contraction will continue to occur as long as the following chemicals are available in the cytosol of the muscle fiber.

a) ATP and acetylcholine (ACh)
b) calcium ions and ATP
c) ACh and potassium ions
d) sodium ions and ATP
e) calcium and ACh

Answer 19

b) calcium ions and ATP

Question 20

24) To stimulate skeletal muscle contraction, acetylcholine must cross the _____ of the neuromuscular junction and bind to receptors on the motor endplate.

a) node of Ranvier
b) synaptic cleft
c) sarcolemma
d) synaptic end bulb
e) transverse tubule

Answer 20

b) synaptic cleft

Question 21

25) Which of the following are commonly used to produce ATP during skeletal muscle contraction?

a) creatine phosphate
b) anaerobic cellular respiration
c) aerobic cellular respiration
d) All of these choices are correct.
e) None of these choices are correct.

Answer 21

d) All of these choices are correct

Question 22

26) In skeletal muscles, the combined amounts of creatine phosphate and ATP provide enough energy for the muscle to contract maximally for approximately

a) 15 seconds.
b) 15 minutes.
c) 1.5 minutes.
d) 5 seconds.
e) one minute.

Answer 22

15 seconds

Question 23

28) Which of the following consists of a somatic motor neuron and all the skeletal muscle fibers it stimulates?

a) sarcomere
b) motor unit
c) neuromuscular junction
d) muscle unit
e) multi-unit smooth muscle

Answer 23

b) motor unit

Question 24

29) A brief contraction of all muscle fibers in a motor unit in response to a single action potential moving down the somatic motor neuron is known as

a) isometric contraction.
b) isotonic contraction.
c) tetany.
d) refractory period.
e) twitch contraction.

Answer 24

e) twitch contraction

Question 25

30) Which of the following is referred to as the period of lost excitability in skeletal muscle fibers? a) refractory period b) contraction period c) latent period d) relaxation period e) wave summation

Answer 25

a) refractory period

Question 26

31) Increasing the number of active motor units within a skeletal muscle is called a) wave summation. b) fused tetanus. c) motor unit recruitment. d) muscle tone. e) flaccidity.

Answer 26

c) motor unit recruitment

Question 27

This is the least powerful type of skeletal muscle fiber. a) slow oxidative fiber b) fast oxidative fiber c) fast glycolytic fiber d) slow glycolytic fiber e) None of these choices.

Answer 27

a) slow oxidative fiber

Question 28

Which of the following microscopic structures is only found in the cardiac muscle tissue? a) myosin b) tropomyosin c) sarcomeres d) intercalated discs e) striations

Answer 28

d) intercalated discs

Question 29

Which of the following types of muscle tissue contract when excited by their own autorhythmic muscle fibers? a) cardiac muscle b) slow twitch oxidative skeletal muscle c) multi-unit smooth muscle d) fast twitch glycolytic skeletal muscle e) All of these choices are correct.

Answer 29

a) cardiac muscle

Question 30

Smooth muscle tone is maintained by the prolonged presence of _____ in the muscle cell’s cytosol? a) ATP b) calcium ions c) phosphate ions d) myoglobin e) None of these choices.

Answer 30

b) calcium ions

Question 31

55) Which of the following disorders is characterized by the wasting away of muscles due to the progressive loss of myofibrils? a) muscular hypertrophy b) muscular atrophy c) fibromyalgia d) myasthenia gravis e) tremors

Answer 31

b) muscular atrophy

Question 32

Which is a NOT a side-effect of anabolic steroid use by male athletes? a) sterility b) baldness c) diminished testosterone secretion d) deepening of the voice e) atrophy of testes

Answer 32

d) deepening of the voice

Question 33

64) Which of the following types of abnormal contractions of skeletal muscle may be caused by holding a position for a prolonged period? a) spasm b) fasciculation c) tremor d) fibrillation e) cramp

Answer 33

Cramp

Question 34

Which of the following is a common effect of aging on skeletal muscle? a) loss of muscle mass b) decrease in maximal strength c) a slowing of muscle reflexes d) loss of flexibility e) all of these are correct

Answer 34

e) all of these are correct

Question 35

Which of the following statements does NOT accurately describe aerobic cellular respiration in skeletal muscles? a) Pyruvic acid generated by glycolysis enters the mitochondria. b) O2 is essential. c) CO2 is produced as a waste product. d) Lactic acid is continually produced. e) Can be used to generate ATP from fats, proteins or carbohydrates.

Answer 35

d) Lactic acid is continually produced

Question 36

After prolonged strenuous exercise has stopped, heavy breathing will often continue for several minutes in order to provide the oxygen needed to a) convert the lactic acid produced during exercise back into glycogen. b) resynthesize creatine phosphate. c) replace oxygen displaced from muscle myoglobin. d) All of these choices e) None of these choices

Answer 36

All of these

Question 37

Which of the following types of muscle tissue is capable of undergoing the stress-relaxation response when they are stretched? a) cardiac muscle fibers b) fast glycolytic fibers c) fast oxidative-glycolytic fibers d) slow oxidative fibers e) single-unit smooth muscle fibers

Answer 37

e) single-unit smooth muscle fibers

Question 38

69). Cross bridges are formed during muscle contraction when _____ on the thick filaments binds to _____ on the thin filaments. a) myosin; troponin b) myosin; troponin c) myosin; actin d) actin; myosin e) actin; tropomyosin

Answer 38

c) myosin; actin

Question 39

In a neuromuscular junction, the effect of acetylcholine (ACh) binding to receptors on the motor end plate lasts only briefly due to a) rapid uptake of the ACh into the myofiber. b) endocytosis of the ACh receptor into the myofiber. c) rapid destruction of ACh in the synaptic cleft by acetylcholinesterase. d) rapid destruction of ACh in the synaptic cleft by monoamine oxidase. e) diffusion of the ACh out of the synaptic cleft.

Answer 39

c) rapid destruction of ACh in the synaptic cleft by acetylcholinesterase.

Question 40

During which period of a twitch contraction does the muscle action potential move along the sarcolemma of the muscle cell and trigger calcium release into the sarcoplasm? a) latent period b) contraction period c) relaxation period d) absolute refractory period e) relative refractory period

Answer 40

a) latent period

Question 41

Which of following is a common characteristic of fast glycolytic (FG) skeletal muscle fibers? a) large amount of myoglobin. b) many mitochondria. c) low concentration of creatine kinase in the sarcoplasm. d) slow myosin ATPase. e) high amount of glycogen in the sarcoplasm.

Answer 41

e) high amount of glycogen in the sarcoplasm.

Question 42

Myasthenia Gravis is an autoimmune disorder that targets the ACh receptors at the NMJ and ultimately reduces the number of available receptors. Predict what happens if you treat the patient with a drug that inhibits the activity of acetylcholinesterase? a) prevent contraction b) weak contraction c) normal contraction d) cause spasm e) none of these choices

Answer 42

c) normal contraction

Question 43

74) Leg muscles are predominantly composed of which type of muscle fiber? a) slow oxidative b) fast glycolytic c) fast oxidative-glycolytic d) slow glycolytic e) fast oxidative

Answer 43

fast oxidative-glycolytic