muscle tissue

Question 1

Myo =

Answer 1

muscle

Question 2

Sarco = flesh (muscle)

Answer 2

flesh (muscle)

Question 3

syn =

Answer 3

together

Question 4

ant =

Answer 4

against

Question 5

agonist =

Answer 5

competitor

Question 6

Iso =

Answer 6

same

Question 7

Epi =

Answer 7

upon

Question 8

Peri =

Answer 8

around

Question 9

Endo =

Answer 9

within

Question 10

what are the 4 functions of muscle tissue?

Answer 10

movement, maintain posture, heat production, and stabilize joints

Question 11

What are the four characteristics that all muscles share?

Answer 11

excitability, contractibility, extensibility, and elasticity

Question 12

what is the function of excitability?

Answer 12

can receive and respond to stimuli

Question 13

what is the function of contractility?

Answer 13

can shorten when stimulated

Question 14

what is the function of extensibility?

Answer 14

can stretch

Question 15

what is the function of elasticity?

Answer 15

can return to original shape

Question 16

T/F: muscle is an organ

Answer 16

true

Question 17

what are the 3 features of the different tissues which make up skeletal muscle?

Answer 17

nerve and blood supply, connective tissue sheaths, and attachments

Question 18

T/F: muscles are energetically expensive

Answer 18

true

Question 19

every skeletal muscle fiber is innervated by a _________

Answer 19

nerve ending

Question 20

muscle is highly vascularized for ___________________

Answer 20

nutrients, oxygen, energy, and waste removal

Question 21

name the CT sheaths from external to internal

Answer 21

epimysium, perimysium, endomysium

Question 22

what type of connective tissue makes up the epimysium?

Answer 22

dense irregular CT tissue

Question 23

what does the epimysium surround?

Answer 23

the epimysium surrounds the whole muscle

Question 24

what type of connective tissue makes up the perimysium?

Answer 24

dense regular connective tissue

Question 25

what does dense regular CT allow the perimysium to do?

Answer 25

allows the muscle to move back and forth; pulls in the same direction

Question 26

what does the perimysium surround?

Answer 26

the perimysium surrounds each fascicle

Question 27

what type of connective tissue makes up the endomysium?

Answer 27

areolar loose CT

Question 28

what does the endomysium surround?

Answer 28

surrounds each muscle fiber

Question 29

what are the three things that make of a muscle fiber?

Answer 29

sarcolemma, sarcoplasm, and sarcoplasmic reticulum

Question 30

characteristics of a muscle fiber

Answer 30

large cells; multi-nucleated

Question 31

what are myofibrils?

Answer 31

organelles

Question 32

what are myofilaments?

Answer 32

filaments

Question 33

what are the two types of myofilaments?

Answer 33

myosin (thick) and actin (thin)

Question 34

myosin =

Answer 34

thick

Question 35

actin =

Answer 35

thin

Question 36

what is the structure of a skeletal muscle in order

Answer 36

muscle, fascicle, muscle fiber, myofibrils, thick and thin filaments

Question 37

the sarcolemma is under the ______

Answer 37

endomysium

Question 38

what is included in the anatomy of a myofibril?

Answer 38

Z line (disc), M line, A band, I band, and sarcomere

Question 39

function of Z line

Answer 39

anchor for thin filaments; actin moves where Z line moves

Question 40

function of M line

Answer 40

anchor for thick filaments

Question 41

A band:

Answer 41

dark area; extends length of the thick filaments

Question 42

I band:

Answer 42

light area; thin myofilaments ONLY; Z disc is center of I band

Question 43

Sarcomere:

Answer 43

functional unit of skeletal muscle; Z disc to z disc; aligned end to end within myofibril

Question 44

in a sarcomere, what moves for a muscle contraction?

Answer 44

both Z lines pull in together

Question 45

what is the functional unit of skeletal muscle?

Answer 45

sarcomere

Question 46

which filament wants to bind to actin?

Answer 46

myosin

Question 47

what makes up thick myofilaments?

Answer 47

myosin myosin makes up thick myofilaments

Question 48

characteristics of myosin

Answer 48

rodlike tail & 2 globular heads

Question 49

what do the heads on myosin contain?

Answer 49

heads contain binding sites for actin & ATP

Question 50

how would you describe the placement of actin on a myofilament?

Answer 50

extends across I band and part way in A band; anchored to Z discs

Question 51

what makes up thin myofilaments?

Answer 51

actin

Question 52

actin contains binding sites for _____

Answer 52

myosin heads

Question 53

charactertisitcs of myosin

Answer 53

G-actin strung together; 2 twisting strands make up thin myofilaments

Question 54

what is the name of the rod-shaped protein which runs along actin?

Answer 54

tropomyosin

Question 55

when the muscle is relaxed, what blocks the myosin-binding sites on actin?

Answer 55

tropomyosin blocks myosin-binding sites on actin when muscle is relaxed

Question 56

what is a key player in the sliding filament model of contraction?

Answer 56

tropinin

Question 57

where is troponin located?

Answer 57

in thin myofilaments

Question 58

T/F: troponin contains a 4 polypeptide subunit complex

Answer 58

FALSE troponin contains a 3 polypeptide subunit complex

Question 59

where does each of the 3 polypeptide subunit complexs in troponin bind to?

Answer 59

1 subunit bound to actin 1 subunit bound to tropomyosin 1 subunit binds to Ca2+

Question 60

where is Ca2+ stored when the muscle is relaxed?

Answer 60

in the sarcoplasmic reticulum

Question 61

definition of a thin filament:

Answer 61

a thin filament consists of two strands of actin subunits twisted into a helix plus two types of regulatory proteins (troponin and tropomyosin)

Question 62

definition of a thick filament:

Answer 62

each thick filament consists of many myosin molecules whose heads protrude at opposite ends of the filament

Question 63

in a relaxed state, thin and thick filaments...

Answer 63

overlap only slightly

Question 64

upon stimulation, myosin heads bind to actin and ________

Answer 64

sliding begins

Question 65

how many steps are in the sliding filament model?

Answer 65

4

Question 66

what is the purpose of the sliding filament model?

Answer 66

it is an explanation for how muscles contract to produce force

Question 67

what are some precursers for the events of contraction

Answer 67

Ca2+ binding to troponin to move tropomyosin and reveal binding sites

Question 68

what are the four sequential events of contraction?

Answer 68

1. cross bridge formation 2. power stroke 3. cross bridge detachment 4. "cocking" of the myosin head

Question 69

what happens in step one of the sliding filament model?

Answer 69

cross bridge formation - myosin attaches to actin filament forming a cross bridge

Question 70

what happens in step two of the sliding filament model?

Answer 70

powerstroke - myosin head picots and pulls actin filament toward M line

Question 71

what happens in step three of the sliding filament model?

Answer 71

cross bridge detachment - myosin head releases from actin

Question 72

what happens in step four of the sliding filament model?

Answer 72

"cocking" of the mysoin head - energy from ATP "cocks" (or energizes) the myosin head for the next power stroke