Chapter 10 Muscle Tissue

Question 1

muscle tissue consists of cells that are highly specialized for the function of

Answer 1

excitability
contraction
extensibility

Question 2

the primary functions performed by skeletal muscles are

Answer 2

produce skeletal movement
guard entrances and exits
maintain body temperature

Question 3

skeletal muscles move the body by

Answer 3

pulling on bones of the skeleton

Question 4

skeletal muscles are often called voluntary muscles because

Answer 4

they contract when stimulated by motor neurons

Question 5

three layers of connective tissue supporting each muscle

Answer 5

epimysium
perimysium
endomysium

Question 6

smallest functional unit of muscle fiber

Answer 6

sarcomere

Question 7

nerves and blood vessels that supply the muscle fibers are contained within the connective tissues of the

Answer 7

endomysium and perimysium

Question 8

the thin filaments consist of

Answer 8

a pair of protein strands wound together to form chains of actin molecules

Question 9

the thick filaments consist of

Answer 9

a helical array of myosin molecules

Question 10

all of the muscle fibers controlled by a single motor neuron constitute a

Answer 10

motor unit

Question 11

the tension in a muscle fiber will vary depending on

Answer 11

• structure of sarcomeres
• length of muscle fibers
• number of cross-bridge interactions

Question 12

the reason there is less precise control over leg muscle compared to the muscle of the eye is

Answer 12

many muscle fibers are controlled by a single motor neuron

Question 13

the sliding filament theory explains that the physical change that takes place during contraction is

Answer 13

the thin filaments sliding toward center of sarcomere alongside thick filaments

Question 14

troponin and tropomyosin are two proteins that can prevent the contractile process by

Answer 14

covering the active site and blocking the actin-myosin interaction

Question 15

the first step in excitation-contraction coupling is

Answer 15

release of calcium ions from cisternae of sarcoplasmic reticulum

Question 16

the amount of tension produced by an individual muscle fiber ultimately depends on

Answer 16

number of pivoting cross-bridges

Question 17

skeletal muscle fibers contract most forcefully when stimulated over a

Answer 17

narrow range of resting lengths

Question 18

the amount of tension produced by a skeletal muscle is controlled by

Answer 18

total number of muscle fibers stimulated

Question 19

peak tension production occurs when all motor units in the muscle contract in a state of

Answer 19

complete tetanus

Question 20

in an isotonic contraction…

Answer 20

cross-bridges must produce enough tension to overcome resistance

Question 21

in an isometric contraction..

Answer 21

tension rises but length of muscle remains constant

Question 22

a high blood concentration of the enzyme creatine phosphokinase usually indicates

Answer 22

serious muscle damage

Question 23

mitochondrial activities are relatively efficient, but their rate of ATP generation is limited by

Answer 23

availability of oxygen

Question 24

during the recovery period, the body’s oxygen demand is

Answer 24

elevated above normal resting levels

Question 25

three major types of skeletal muscle fibers in the human body

Answer 25

slow
intermediate
fast

Question 26

extensive blood vessels, mitochondria, and myoglobin are found in the greatest concentration in

Answer 26

slow fibers

Question 27

the length of time a muscle can continue to contract while supported by mitochondrial activities

Answer 27

aerobic endurance

Question 28

altering the characteristics of muscle fibers and improving the performance of the cardiovascular system results in improving

Answer 28

aerobic endurance

Question 29

the property of cardiac muscle that allows it to contract without neural stimulation

Answer 29

automaticity

Question 30

the type of muscle cell that locks sarcomeres and the resulting striations

Answer 30

smooth

Question 31

structurally, smooth muscle cells differ from skeletal muscle cells because smooth muscle cells..

Answer 31

lack myofibrils and sarcomeres

Question 32

smooth muscle tissue differs from other muscle tissue in

Answer 32

excitation-contraction coupling
length-tension relationships
control of contraction

Question 33

neural, hormonal, or chemical factors can stimulate smooth muscle contraction producing

Answer 33

a decrease in muscle tone

Question 34

layers of smooth muscle in the reproductive tract of the female are important in

Answer 34

movement of ova
movement of sperm if present
expelling of the fetus at delivery