MUSCULAR SYSTEM

Question 1

7 functions of the muscular system

Answer 1

body movement
posture maintenance
respiration
production of body heat
communication
constriction of organs and blood vessels
contraction of heart

Question 2

3 types of muscles

Answer 2

skeletal muscle
smooth muscle
cardiac muscle

Question 3

long, cylindrical type of muscle

Answer 3

skeletal

Question 4

has spindle-shaped cells type of muscle

Answer 4

smooth muscle

Question 5

has branched and cylindrical cells type of muscle

Answer 5

cardiac muscle

Question 6

special cell-to-cell attachment of smooth muscle

Answer 6

gap junctions

Question 7

special cell-to-cell attachments of cardiac muscle

Answer 7

intercalated disks

Question 8

where is the nuclei of skeletal muscles located

Answer 8

periphery (multinucleated)

Question 9

which type of muscle has no striations

Answer 9

smooth muscle

Question 10

which type of muscle is capable of voluntary control

Answer 10

skeletal muscle

Question 11

which muscle type can be found in the walls of hollow organs, blood vessels, glands, and skin

Answer 11

smooth muscle

Question 12

4 general properties of muscle tissue

Answer 12

contractility
excitability
extensibility
elasticity

Question 13

ability of muscle to respond to stimulus

Answer 13

excitability

Question 14

ability of muscle to shorten forcefully

Answer 14

contractility

Question 15

ability of muscle to stretch beyond its normal resting length

Answer 15

extensibility

Question 16

ability of muscle to recoil

Answer 16

elasticity

Question 17

3 connective tissue coverings within the muscle

Answer 17

epimysium (outer)
perimysium (fascicles)
endomysium (muscle fibers)

Question 18

this connective tissue sheath surrounds each skeletal muscle

Answer 18

epimysium

Question 19

this connective tissue covering surrounds each muscle fascicle within the skeletal muscle

Answer 19

perimysium

Question 20

this connective tissue covering surrounds each individual muscle fiber within fascicles

Answer 20

endomysium

Question 21

2 main aspects of muscle contraction

Answer 21

electrical component (sarcolemma, t tubules, sarcoplasmic reticulum)
mechanical component (myofibril, myofilaments)

Question 22

these are bundles of protein filaments

Answer 22

myofibrils

Question 23

2 types of myofilaments that make up myofibrils

Answer 23

actin
myosin

Question 24

structural and functional units of skeletal muscles

Answer 24

sacromeres

Question 25

3 proteins of actin myofilament

Answer 25

actin troponin tropomyosin

Question 26

this is composed of many elongated myosin molecules shaped like golf clubs

Answer 26

myosin filaments

Question 27

shape of myosin molecules

Answer 27

golf club

Question 28

TRUE OR FALSE: The rods of myosin molecules break down ATP releasing energy

Answer 28

FALSE (rods --> heads)

Question 29

this is the parallel arrangement of myofilaments that cause muscle contraction

Answer 29

sliding filament model

Question 30

TRUE OR FALSE during muscle contraction, sarcomeres lengthen

Answer 30

FALSE

Question 31

TRUE OR FALSE muscle fibers are electrically excitable

Answer 31

TRUE

Question 32

TRUE OR FALSE the basis of the electrical properties of skeletal muscle cells is the movement of ions across the cell membrane

Answer 32

TRUE

Question 33

2 types of ion channels

Answer 33

leak ion channels gated ion channels

Question 34

in resting cells, ______ ion channels allow for the slow leak of ions down their concentration gradient

Answer 34

leak

Question 35

in ___________ cells, gated ion channels are the most important

Answer 35

stimulated

Question 36

this is the charge difference in an unstimulated cell

Answer 36

resting membrane potential

Question 37

the resting membrane potential results in 3 factors:

Answer 37

1. K concentration is higher inside the cell membrane 2. Na concentration is higher outside the cell membrane 3. cell membrane is more permeable to K than Na

Question 38

this occurs when the excitable cell is stimulated

Answer 38

action potential

Question 39

2 phases of action potential

Answer 39

depolarization repolarization

Question 40

when action potential is generated, the inside of the cell membrane becomes ____________ charged (positive or negative)

Answer 40

positive

Question 41

an action potential is triggered when depolarization causes the cell membrane to reach ____________

Answer 41

threshold

Question 42

this phase of the action potential is a brief period where the inside of the cell membrane becomes positively charged

Answer 42

depolarization

Question 43

this phase of the action potential is a brief period where Na channels close and K channels open; the membrane potential returns to its resting value

Answer 43

repolarization

Question 44

what happens when the cell becomes more positively charged that stops depolarization and leads to repolarization

Answer 44

the voltage change causes additional permeability

Question 45

release of _________ from the sarcoplasmic reticulum triggers muscle contraction

Answer 45

Calcium (Ca2+)

Question 46

release of _____________ at the neuromuscular junction produces an action potential in the sarcolemma

Answer 46

acetylcholine

Question 47

this occurs when acetylcholine is no longer released at the neuromuscular junction

Answer 47

muscle relaxation

Question 48

this keeps acetylcholine from accumulating within the synaptic cleft

Answer 48

acetylcholinesterase

Question 49

this is the mechanical component of muscle contraction (attachment of myosin to actin)

Answer 49

cross-bridge movement

Question 50

this is the response of a muscle fiber to a single action potential along its motor neuron

Answer 50

muscle twitch

Question 51

3 phases of muscle twitch

Answer 51

lag phase contraction phase relaxation phase

Question 52

the gap between the time of stimulus application to the motor neuron and the beginning of contraction in muscle twitch

Answer 52

lag phase

Question 53

this occurs once Ca2+ is released from the sarcoplasmic reticulum, initiating cross-bridge formation and cross-bridge cycling (in muscle twitch)

Answer 53

contraction phase

Question 54

TRUE OR FALSE contraction phase is longer than the relaxation phase

Answer 54

FALSE (it's the other way around)

Question 55

types of muscle contractions

Answer 55

isometric isotonic

Question 56

muscle contraction where the muscle does not shorten

Answer 56

isometric

Question 57

muscle contraction where the muscle shortens

Answer 57

isotonic

Question 58

types of isotonic contraction

Answer 58

concentric eccentric

Question 59

isotonic contraction where: tension > opposing resistance

Answer 59

concentric

Question 60

isotonic contraction where: tension < opposing resistance (muscle length increases)

Answer 60

eccentric

Question 61

2 major types of skeletal muscle fibers

Answer 61

slow-twitch muscle fibers (type I) fast-twitch muscle fibers (type II)

Question 62

muscle fiber type with more blood supply, more mitochondria, high myoglobin content, and contract more slowly

Answer 62

slow-twitch oxidative muscle fibers (SO; type I)

Question 63

muscle fiber type that has fewer blood supply and mitochondria, and have myosin heads with a fast form of enzyme to breakdown ATP, resulting in faster muscle contraction

Answer 63

fast-twitch muscle fibers (type II)

Question 64

this is the temporary state of reduced work capacity of the msucle

Answer 64

muscle fatigue

Question 65

mechanisms underlying muscle fatigue

Answer 65

acidosis and ATP depletion oxidative stress local inflammatory reactions

Question 66

this is the build up of excess reactive oxygen species that causes muscle fatigue

Answer 66

oxidative stress

Question 67

TRUE OR FALSE highly repetitive concentric muscle contractions produce pain more readily than eccentric muscle contractions

Answer 67

FALSE (repetitive eccentric MC produce more pain and soreness)

Question 68

TRUE OR FALSE smooth muscles contain less actin and myosin than skeletal muscles

Answer 68

TRUE

Question 69

TRUE OR FALSE smooth muscles contract faster than skeletal muscles

Answer 69

FALSE (they contract more slowly)

Question 70

what connects muscles to bones

Answer 70

tendons

Question 71

points of attachment ng muscles

Answer 71

origin insertion

Question 72

the most stationary/fixed end of the muscle (attachment)

Answer 72

origin

Question 73

the end of the muscle attached to the bone undergoing the greatest movement (attachment)

Answer 73

insertion

Question 74

this is a specific body movement caused by a muscle contraction

Answer 74

action

Question 75

muscles that play a major role in accomplishing a desired movement

Answer 75

prime mover

Question 76

muscles that hold one bone in place relative to the body while a usually more distal bone is moved

Answer 76

fixators

Question 77

3 fascicle arrangements

Answer 77

circular convergent parallel