Chapter 10 and 11: Muscles and Muscle Tissues

Question 1

4 properties and that distinguish muscle tissue from other tissues

Answer 1

contractility, excitability, extensibility, and elasticity

Question 2

contractility

Answer 2

muscle tissue contracts forcefully

Question 3

excitability

Answer 3

nerve signals or other stimuli excite muscle cells

Question 4

extensibility

Answer 4

muscle tissue can be stretched

Question 5

elasticity

Answer 5

muscle tissue can recoil passively and resume its resting length

Question 6

functions of muscle tissue

Answer 6

produce movement, open and close body passageways, maintains posture and stabilize joints, and heat generation

Question 7

skeletal muscle tissue

Answer 7

skeletal muscles that are striated; innervated by voluntary division of nervous system

Question 8

cardiac muscle tissue

Answer 8

striated muscles only in walls of heart; innervated by the involuntary division of the nervous system

Question 9

smooth muscle tissue

Answer 9

walls of hollow organs; lack striations; innervated by involuntary division of nervous system

Question 10

epimysium

Answer 10

dense irregular connective tissue surrounding entire muscle

Question 11

perimysium

Answer 11

surrounds each fascicle (group of muscle fibers)

Question 12

endomysium

Answer 12

fine sheath of loose connective tissue wrapping each muscle cell

Question 13

muscle attachments

Answer 13

most skeletal muscles run from one bone to another, crossing 1 moveable joint

Question 14

insertion

Answer 14

more moveable

Question 15

origin

Answer 15

less moveable

Question 16

skeletal muscle fiber

Answer 16

long, cylindrical fibers; huge cells; each cell formed by the fusion of hundreds of embryonic cells; nuclei are peripherally located

Question 17

myofibrils

Answer 17

rodlike bundle of contractile myofilaments in the cytoplasm of a skeletal muscle cell; made of repeating segments called sarcomeres

Question 18

Z disc (Z line)

Answer 18

boundaries at the two ends of each sarcomere

Question 19

thin (actin filaments)

Answer 19

attached to each Z disc and extending toward the center of the sarcomere; composed of actin

Question 20

thick (myosin) filaments

Answer 20

located in the center of the sarcomere; overlap inner ends of the thin filaments; contain ATPase enzymes

Question 21

A bands

Answer 21

full length of the thick filaments; includes inner end of thin filaments

Question 22

H zone

Answer 22

center part of A band where no thin filaments occur

Question 23

M line

Answer 23

in center of H zone; contains tiny rods that hold thick filaments together

Question 24

I band

Answer 24

region with only thin filaments; lies within two adjacent sarcomeres

Question 25

T tubules

Answer 25

deep invaginations of sarcolemma that run between each pair of terminal cisterns

Question 26

Triad

Answer 26

T tubule flanked by two cisterns

Question 27

axial muscles

Answer 27

their origin and insertion in the axial skeleton; affect facial features, chewing, aid in breathing, and organ support

Question 28

appendicular mucles

Answer 28

have their origin and insertion in the appendicular skeleton; move limbs

Question 29

circular muscles

Answer 29

concentrically arranged fibers around an opening called a sphincter; contraction decreases the diameter of the passage

Question 30

parallel muscles

Answer 30

parallel to the long axis; central body called the belly; when they shorten, their diameter increases

Question 31

convergent muscles

Answer 31

widespread fibers that converge at the common site; triangular in shape; direction of pull can be changed by which fibers are active; not as strong as parallel when they contract

Question 32

pennate muscles

Answer 32

named for their shape (penna means feather); the fascicles have the same angle with respect to a tendon; one or more tendons through the body of the muscle

Question 33

agonists

Answer 33

prime mover of a joint; contract to make a particular movement

Question 34

antagonist

Answer 34

actions oppose the agonist

Question 35

synergists

Answer 35

assist the agonist with performing its action

Question 36

muscle naming schemes

Answer 36

action, body region, muscle attachments, fiber orientation, muscle shape, muscle size, and muscle heads or tendons of origin

Question 37

concentric contraction

Answer 37

muscle shortens and does work

Question 38

eccentric contraction

Answer 38

muscle generates force as it lengthens

Question 39

muscle extension

Answer 39

after muscle is stretched they contract; amount of overlap between the thin and thick filaments decreases

Question 40

neuromuscular junction

Answer 40

where nerve ending and muscle fiber meet

Question 41

axon terminals

Answer 41

at ends of axons; store neurotransmitters

Question 42

synaptic cleft

Answer 42

space between axon terminal and sarcolemma

Question 43

motor unit

Answer 43

a motor neuron and all of the muscle cells it stimulates

Question 44

slow oxidative fibers (aerobic; many mitochondria)

Answer 44

red(lots of myoglobin); many capillaries slow contraction; fatigue resistant

Question 45

fast glycolytic fibers (anaerobic; few mitochondria)

Answer 45

white (little myoglobin powerful; contract and tire quickly

Question 46

fast oxidative fibers

Answer 46

red (myoglobin); many capillaries; contract quickly; more powerful than slow oxidative and somewhat fatigue resistant