Muscular System

Question 1

a body tissue that functions for contraction or shortening

Answer 1

muscle

Question 1

a body tissue that functions for contraction or shortening

Answer 1

muscle

Question 2

they are responsible for essentially all body movement

Answer 2

muscle

Question 3

they are a dominant tissue in the heart and in the walls of other hollow organs of the body
it makes up nearly half of the body mass

Answer 3

muscle

Question 4

[muscle functions]
contraction of muscles attached to bones produces movements under voluntary control

Answer 4

producing movement

Question 5

[muscle functions]
muscle attached to the bones keep the body upright despite the pull of gravity and stabilize the joints

Answer 5

maintaining posture

Question 6

[muscle functions]
contraction of the skeletal muscles of the thorax and the diaphragm help us breathe

Answer 6

respiration

Question 7

[muscle functions]
metabolic activity in the muscles generate abundant heat as by-product and is needed in maintaining body temperature

Answer 7

generating heat

Question 8

[muscle functions]
skeletal muscles are involved in all aspects of __________, including speaking, writing, typing, gesturing, and smiling or frowning

Answer 8

communication

Question 9

[muscle functions]
the contraction of smooth muscle within the walls of internal organs and vessels causes those structures to constrict

Answer 9

constriction of organs and vessels

Question 10

[muscle functions]
the contraction of cardiac muscle causes the heart to beat, propelling blood to all parts of the body

Answer 10

contraction of the heart

Question 11

what are the three muscle types

Answer 11

skeletal muscles
cardiac muscles
smooth muscles

Question 12

voluntary muscles attached to bones

Answer 12

skeletal muscles

Question 13

locomotion, facial expressions, posture, respiratory functions, speech, and other body movements are due to __________ contraction

Answer 13

skeletal muscle

Question 14

the __________ controls the voluntary aspects of skeletal muscle

Answer 14

nervous system

Question 15

involuntary muscles found only in the heart

Answer 15

cardiac muscles

Question 16

its contractions provide the major force for moving blood through the circulatory system

Answer 16

cardiac muscle

Question 17

involuntary muscles widely distributed in the body such as in the walls of hollow visceral organs, stomach, intestines, uterus, blood vessels, ducts of glands, and respiratory passages

Answer 17

smooth muscles

Question 18

__________ contraction propels urine through the urinary tract, mixes food in the stomach and small intestine, and regulates the flow of blood through blood vessels

Answer 18

smooth muscle

Question 19

they are made up of single, very long and cylindrical cells with very obvious striations

Answer 19

skeletal muscle

Question 20

they are made up of branching chains of cells with striations

Answer 20

cardiac muscles

Question 21

they are made up of cells with no striations

Answer 21

smooth muscles

Question 22

what are the four muscle properties

Answer 22

contractility
excitability
extensibility
elasticity

Question 23

[muscle properties]
the ability of muscle to shorten forcefully

Answer 23

contractility

Question 24

[muscle properties] the capacity of the muscle to respond to an electrical stimulus

Answer 24

excitability

Question 25

[muscle properties] a muscle can be stretched beyond its normal resting length and still be able to contract

Answer 25

extensibility

Question 26

[muscle properties] the ability of muscle to spring back to its original resting length after it has been stretched

Answer 26

elasticity

Question 27

individual muscle cell (with a length range from 1 to 40 mm) that contains multiple nuclei and other organelles

Answer 27

muscle fiber or myocyte

Question 28

bundle of parallel skeletal muscle fibers

Answer 28

fasicle

Question 29

layer of connective tissue that surrounds individual muscles and group of muscles these outer layer keep the muscles separate from surrounding tissues and organs

Answer 29

muscle fascia

Question 30

forms a connective tissue sheath that surrounds each skeletal muscle its protein fibers gradually merge with the muscular fascia

Answer 30

epimysium

Question 31

connective tissue sheath that surrounds fascicles, subdividing each whole muscle into numerous bundles of muscle fibers

Answer 31

perimysium

Question 32

delicate layer of connective tissue that separates the individual muscle fibers within each fasicle it serves as passageways for nerve fibers and blood vessels that supply each separate muscle fiber

Answer 32

endomysium

Question 33

plasma membrane of muscle fibers

Answer 33

sarcolemma

Question 34

tube-like inward folds of the sarcolemma

Answer 34

transverse tubules or T tubules

Question 35

at regular intervals along the muscled fiber, the sarcolemma forms __________ by projecting and extending into the interior of the muscle fiber

Answer 35

T tubules

Question 36

they carry electrical impulses into the center of the muscle fiber so that every contractile unit of the muscle fiber contracts in unison

Answer 36

T tubules

Question 37

highly specialized smooth endoplasmic reticulum in skeletal muscle fibers that stores high levels of calcium

Answer 37

sarcoplasmic reticulum

Question 38

enlarged portions of the sarcoplasmic reticulum T tubules lie next to it

Answer 38

terminal cisternae

Question 39

formed by two terminal cisternae and their associated T tubule

Answer 39

triad

Question 40

bundle of parallel protein filaments running the length of the muscle fiber hundreds to thousands of cylindrical __________ occupy the most of the cell's volume

Answer 40

myofibril

Question 41

structural and functional unit of the myofibril the smallest portion of a muscle that can contract

Answer 41

sarcomere

Question 42

individual thick and thin filaments that make up a myofibril the interaction of these are the basis of muscle contraction

Answer 42

myofilaments

Question 43

a thin filament of two entwined strands of proteins that makes up the sarcomere

Answer 43

actin

Question 44

a long fibrous protein that lies in the groove along the fibrous actin strand

Answer 44

tropomyosin

Question 45

in a relaxed muscle, __________ is covering the active sites of the actin where thick myosin filament binds a muscle cannot contract until it moves to uncover the active sites

Answer 45

tropomyosin

Question 46

attached to tropomyosin and lies within the groove between actin filaments in the muscle tissue

Answer 46

troponin

Question 47

a thick filament of protein that also makes up the sarcomere

Answer 47

myosin

Question 48

bind and pull on the actin filaments, causing actin to slide in between each myosin set, therefore shortening the entire contractile unit when this process is duplicated across many sarcomere units, the entire muscle or group of mucles is enabled to contract, consequently causing a desired movement

Answer 48

myosin heads

Question 49

made up of a motor neuron synapsed to the muscle fibers

Answer 49

motor unit

Question 50

carry action potentials or electrical signals which stimulate muscles to contract

Answer 50

motor neurons

Question 51

is the point of contact of motor neuron axon branches with the muscle fiber

Answer 51

neuromuscular junction or synapse

Question 52

the neurotransmitter that stimulates the skeletal muscle fibers to contract

Answer 52

acetycholine

Question 53

occurs when acetylcholine is no longer released at the neuromuscular junction

Answer 53

muscle relaxation

Question 54

type of contractions where a muscle does not shorten this type of contraction increases the tension in the muscle, but the length of the muscle stays the same

Answer 54

isometric contractions

Question 55

type of contractions where the muscle shortens this type of contraction increases the tension in the muscle and the length of the muscle decreases

Answer 55

isotonic contractions

Question 56

isotonic contractions in which tension in the muscle is great enough to overcome the opposing resistance, and the muscle shortens

Answer 56

concentric contractions

Question 57

isotonic contractions in which tension is maintained in a muscle, but the opposing resistance is great enough to cause the muscle to increase the length

Answer 57

eccentric contractions

Question 58

[antagonistic muscle pairs] prime mover muscles that causes a particular movement

Answer 58

agonist muscles

Question 59

[antagonistic muscle pairs] muscles that oppose or reverse a movement

Answer 59

antagonist muscles

Question 60

[antagonistic muscle pairs] help agonists by producing the same movement or by reducing undesirable movements

Answer 60

synergist muscles

Question 61

[antagonistic muscle pairs] are specialized synergists they hold a bone still or stabilize the origin of the agonist muscles so all the tension can be used to move the insertion bone

Answer 61

fixator muscles

Question 62

all muscles have at least two attachments: __________

Answer 62

origin or fixed end insertion or mobile end

Question 63

muscle is attached to the immovable or less movable bone in its proximal end some muscles have more than one __________

Answer 63

origin or fixed end

Question 64

muscle is attached to the movable bone in its distal end the attached bone is being pulled toward the other bone of the joint

Answer 64

insertion or mobile end

Question 65

muscles can only __________ and can never __________

Answer 65

can only pull can never push

Question 66

during contraction, the muscle insertion moves __________ the origin

Answer 66

moves toward

Question 67

can greatly influence the degree to which it can contract and the amount of force it can generate

Answer 67

muscle shape

Question 68

determines the type of movement it has and is determined by the arrangement of fasicles

Answer 68

muscle shape

Question 69

[muscle shapes] have their fasicles arranged in a circle around an opening and act as sphincters to close the opening

Answer 69

circular muscles

Question 70

[muscle shapes] have fasicles that join at one common tendon from a wide area, which created muscles that are triangular in shape

Answer 70

convergent muscles

Question 71

[muscle shapes] similar with convergent muscles, have fasicles that are organized parallel to the long axis of the muscle, but they terminate on a flat tendon that spans the width of the entire muscle

Answer 71

parallel muscles

Question 72

[muscle shapes] fasicles run the length of the entire muscle and taper at each end to terminate at tendons these muscles have expanded midsection that the ends

Answer 72

fusiform muscles

Question 73

[muscle shapes] have fasicles that emerge like the barbs on a feather from a common tendon that runs the length of the entire muscle

Answer 73

pennate muscle

Question 74

[muscle shapes] fasicles are on one side of the tendon

Answer 74

unipennate muscles

Question 75

[muscle shapes] fasicles arranged on two sides of the tendon

Answer 75

bipennate muscles

Question 76

[muscle shapes] fasicles arranged at many places around the central tendon

Answer 76

multipennate muscles