Muscular Tissues Part 2

Question 1

outer layer, encircling the entire muscle

Answer 1

epimysium

Question 2

surrounds groups of 10 to 100 or more muscle fibers, separating them into bundles called fascicles

Answer 2

perimysium

Question 3

surrounds and separates individual muscle fibers from one another

Answer 3

endomysium

Question 4

three kinds of proteins:

Answer 4

contractile proteins
regulatory proteins
structure proteins

Question 5

generate force during contraction

Answer 5

contractile protein

Question 6

help switch the contraction process on and off

Answer 6

regulatory proteins

Question 7

keep thick and thin filaments of myofibrils in proper alignment, give myofibrils elasticity and extensibility, and link myofibrils to sarcolemma and extracellular matrix

Answer 7

structural proteins

Question 8

two types of contractile proteins

Answer 8

myosin
actin

Question 9

makes up thick filament; a molecule consists of a tail and two myosin heads, which bind to myosin-binding sites on actin molecules of thin filament during muscle contraction

Answer 9

myosin

Question 10

these two both functions as a motor protein in all three types of muscle tissue

Answer 10

myosin and actin

Question 11

main component of thin filament; each one of this molecule has a myosin-binding site where myosin head of thick filament binds during muscle contraction

Answer 11

actin

Question 12

two types of regulatory proteins

Answer 12

tropomyosin
troponin

Question 13

component of thin filament; when skeletal muscle fiber is relaxed, this covers myosin/binding sites in actin molecules, thereby preventing myosin from binding to actin

Answer 13

tropomyosin

Question 14

makes up thick filament; molecule consists of a tail and two myosin heads, which bind to myosin-binding sites in actin molecules of thin filament during muscle contraction

Answer 14

troponin

Question 15

five types of structural proteins

Answer 15

Titin
a-Actinin
Myomesin
Nebulin
Dystrophin

Question 16

connects z disc to M line of sarcomere, thereby helping to stabilize thick filament position; can stretch and then spring back unharmed, and thus accounts for much of the elasticity and extensibility of myofibrils

Answer 16

titin

Question 17

structural protein of z discs that attaches to actin molecules of thin filaments and to titin molecules

Answer 17

a-actinin

Question 18

forms m line of sarcomere; binds to titin molecules and connects adjacent thick filaments to one another

Answer 18

myomesin

Question 19

wraps around entire length of each thin filament; helps anchor thin filaments to z discs and regulates length of thin filaments during development

Answer 19

nebulin

Question 20

links thin filaments of sarcomere to integral membrane proteins in sarcolemma, which are attached in turn to proteins in connective tissue matrix that surrounds muscle fibers; thought to help reinforce sarcolemma and help transmit tension generated by sarcomeres to tendons

Answer 20

dystrophin

Question 21

skeletal muscle fibers are classified into three main types:

Answer 21

slow oxidative fibers
fast oxidative-glycolytic fibers
fast glycolytic fibers

Question 22

two fibers that appear dark red bcs of large amounts of myoglobin and many blood capillaries

Answer 22

slow oxidative fiber
fast oxidative-glycolytic fiber

Question 23

both contains large mitochondria therefore generate ATP mainly by aerobic respiration

Answer 23

slow oxidative fiber
fast oxidative-glycolytic fiber

Question 24

ATPase in the myosin heads hydrolysis ATP relatively slow

Answer 24

slow oxidative fibers

Question 25

ATPase in the myosin heads hydrolyzes ATP 3-5x faster than myosin ATPase in SO fibers

Answer 25

fast oxidative-glycolytic fibers

Question 26

both can also generate ATP by anaerobic glycolysis due to high levels of intracellular glycogen level

Answer 26

fast oxidative-glycolytic fibers fast glycolytic fibers

Question 27

very resistant to fatigue

Answer 27

slow oxidative fibers

Question 28

moderately resistance to fatigue

Answer 28

fast oxidative-glycolytic fiber

Question 29

adapted fro maintains posture and for aerobic, endurance-tyoe activities

Answer 29

slow oxidative fibers

Question 30

twitches of this reach tension more quickly than those of SO fibers but are briefer in duration

Answer 30

fast oxidative-glycolytic fibers

Question 31

contribute to activities like walking and sprinting

Answer 31

fast oxidative-glycolytic fibers

Question 32

low myoglobin content, few blood capillaries, few mitochondria, and appear white in color

Answer 32

fast glycolytic fibers

Question 33

this contract strongly and quickly due to ability to hydrolyze ATP rapidly

Answer 33

fast glycolytic fibers

Question 34

adopted for intense anaerobic movements of short duration

Answer 34

fast glycolytic fibers

Question 35

fatigued quickly

Answer 35

fast glycolytic fibers

Question 36

type of muscle tissue that is located in heart and large vessels attached to heart

Answer 36

cardiac muscle tissue

Question 37

branched cylindrical fiber with one centrally located nucleus; striated

Answer 37

cardiac muscle tissue

Question 38

develop from mesodermal cells that migrate to and envelope the developing heart while it is still in the form of endocardial heart tubes

Answer 38

cardiac muscle tissue

Question 39

length of cardiac muscle fiber

Answer 39

long (50-100um)

Question 40

diameter of cardiac muscle fiber

Answer 40

large (10-20um)

Question 41

T/F: t tubules located at z lines are smaller than in skeletal muscle

Answer 41

FALSE

Question 42

T/F: sarcoplasmic reticulum in cardiac muscle is less well developed

Answer 42

TRUE

Question 43

found in walls of hollow viscera, airways, blood vessels etc

Answer 43

smooth muscle tissue

Question 44

fibers are in fusiform in shape (thickest jn middle, tapered at each end)

Answer 44

smooth muscle

Question 45

contain one centrally positioned nucleus and not striated

Answer 45

smooth muscle tissue

Question 46

develop from mesodermal cells that migrate or and envelop the developing gastrointestinal tract and viscera

Answer 46

smooth muscle

Question 47

length of smooth muscle fiber

Answer 47

intermediate (30-200um)

Question 48

diameter of smooth muscle fiber

Answer 48

small (3-8um)

Question 49

actin and myosin form ______ network and insert into dense bodies in the sarcoplasm

Answer 49

lattice (criss-cross)

Question 50

it has gap junctions couple muscle and allow ionic communication between all fibers

Answer 50

smooth muscle fiber

Question 51

T/F: t Tubules are PRESENT in smooth muscle fiber

Answer 51

FALSE

Question 52

short membrane invaginations, called _____, are often frequent at the smooth muscle cell structure

Answer 52

caveolae

Question 53

T/F: smooth muscle fiber has very little sarcoplasmic reticulum

Answer 53

TRUE

Question 54

regulatory proteins of smooth muscle fiber:

Answer 54

myosin light-chain kinase (MLCK) calmodulin

Question 55

regulatory proteins of cardiac muscle fiber:

Answer 55

tropomyosin and troponin