Ch.12 Quiz

Question 1

Muscles which move a limb away the midline of the body are ________ muscles.

extensor

abductor

adductor

flexor

Answer 1

abductor

Question 2

Each somatic motor neuron with all the muscle fibers it innervates is a ________.

varicosity

sarcolemma

motor unit

fascicle

Answer 2

motor unit

Question 3

Increased motor unit recruitment causes ________ force generation by a muscle.

no change in

increased

decreased

Answer 3

increased

Question 4

What protein primarily makes up the thick filament?

Actin

Troponin

Myosin

Titin

Answer 4

myosin

Question 5

Which molecule blocks the myosin head from binding to actin in a relaxed muscle?

Tropomyosin

Calcium

Troponin

Titin

Answer 5

tropomyosin

Question 6

The process by which action potentials cause muscle contraction is known as________.

cross-bridge cycling

excitation-relaxation coupling

excitation-contraction coupling

the sliding filament theory

Answer 6

excitation-relaxation coupling

Question 7

What structure runs the length of the sarcomere and contributes to the elastic recoil in muscle?

Titin

Z disk

Actin

M line

Answer 7

Titin

Question 8

The pumps that actively transport calcium back into the ________ are called Ca2+ -ATPase pumps.

transverse tubules

sarcoplasmic reticulum

neuromuscular junction

None of the choices are correct.

Answer 8

sarcoplasmic reticulum

Question 9

The inability of muscle cells to relax due to high frequency stimulation is called ________.

tetanus

treppe

twitch

recruitment

Answer 9

tetanus

Question 10

The series-elastic component of contraction ________.

provides for elastic recoil when muscles contract

is unrelated to muscle shortening

is not provided by tendons

absorbs some of the tension of muscle contraction

Answer 10

absorbs some of the tension of muscle contraction

Question 11

In regards to the relationship between resting muscle fiber length and tension generated, ________.

maximal tension is generated when the thick and thin filaments do not overlap

maximal tension is generated when the thick and thin filaments slightly overlap

maximal tension is generated when the thick and thin filaments greatly overlap

the amount of overlap is unimportant in determining maximal tension

Answer 11

maximal tension is generated when the thick and thin filaments slightly overlap

Question 12

Fast glycolytic/Type IIX white muscle fibers ________.

are predominantly recruited during low intensity activities

have a high oxidative capacity

have many capillaries

have a high glycogen content

Answer 12

have a high glycogen content

Question 13

Insertion of ________ in the muscle cell membrane increases cellular glucose uptake.

GLUT3

GLUT4

GLUT2

GLUT1

Answer 13

GLUT 4

Question 14

Muscle repair is due to ________ forming myotubes that fuse to form new muscle fibers.

satellite cells

myofibrils

muscle cells

All of the choices are correct.

Answer 14

satellite cells

Question 15

Skeletal muscles at rest obtain most of their energy from the aerobic respiration of ________.

glucose

protein

glycogen

fatty acids

Answer 15

fatty acids

Question 16

Fatty acids provide the majority of the energy for muscle metabolism when a person is exercising at ________.

100% of VO2max
75% of VO2max
50% of VO2max
25% of VO2max

Answer 16

25% of VO2max

Question 17

Alpha motor neurons innervate ________.

nuclear bag fibers

intrafusal fibers

extrafusal fibers

nuclear chain fibers

Answer 17

extrafusal fibers

Question 18

The muscle spindle is associated with ________.

tendons

extrafusal fibers

intrafusal fibers

Golgi tendon organs

Answer 18

intrafusal fibers

Question 19

An individual steps on a nail with her left foot. In response to this, what reflex responses should occur?

Both the flexors and extensors of the ipsilateral side would contract.

The flexor muscles of the left leg will contract to maintain balance.

Only the flexors on the contralateral side would contract.

The extensor muscles of the right leg will contract to maintain balance.

Answer 19

The extensor muscles of the right leg will contract to maintain balance.

Question 20

Choose the statement that correctly categorizes cardiac muscle tissue.

The fibers lack I and A bands.

The intercalated discs contain gap junctions.

The fibers of cardiac muscle lack branches.

Dense bodies anchor thin filaments.

Answer 20

The intercalated discs contain gap junctions.