Muscle Function pt 1

Question 1

3 types of muscle

Answer 1

skeletal

cardiac

smooth

Question 2

muscle fiber types

Answer 2

Type IA

Type IIA

Type IIB

Question 3

can individual muscles have different fiber types?

Answer 3

yes

an individual muscle can contain multiple fiber types

Question 4

how are variations of muscle fibers believed to be determined?

Answer 4

genetically

Question 5

Type I muscle fibers visually

Answer 5

dark (d/t containing larger numbers of mitochondria and a high concentration of myoglobin)

Question 6

how are type I muscle fibers referred to

Answer 6

slow-twitch or slow oxidativve

Question 7

do type I muscle fibers contract over a long or short period of time

Answer 7

long period of time

Question 8

type IIB muscle fibers visually

Answer 8

pale (d/t fewer mitochondria and only small amounts of myoglobin)

Question 9

how are type IIB fibers referred to

Answer 9

fast-twitch or fast glycolytic

Question 10

which muscle fiber type are largest in diameter

Answer 10

type IIB

Question 11

what happens as the muscle fiber’s diameter increases

Answer 11

it generates more force

Question 12

which muscle fiber will twitch quicker

Answer 12

type IIB

Question 13

which muscle fiber fatigues the quickest

Answer 13

type IIB

Question 14

type IIA fibers visually

Answer 14

intermediate in characteristics

-middle amounts of mitochondrion and myoglobin

-fiber diameter is smaller than IIA but larger than I

-don’t fatigue as quickly as type IIA, but don’t last as long as I

-speed of contraction is quicker than type I, but slower than IIA

Question 15

how are type IIA muscle fibers referred

Answer 15

fast oxidative-glycolytic

Question 16

what are muscles with a high proportion of type I fibers able to do

Answer 16

carry on sustained activity d/t the fibers not fatiguing quickly

Question 17

what muscles are considered to have high proportions of type I fibers

Answer 17

stability and postural muscles

ex: soleus, adductor pollicis, tibialis anterior

Question 18

what are muscles with a high proportion of type IIA fibers referred to as

Answer 18

mobility or non postural or phasic muscles

Question 19

what do muscles with high proportions of type IIA fibers do

Answer 19

-produce larger ROM

-respond quickly to a stimulus

-fatigue more rapidly

ex: biceps brachii

Question 20

what happens when structure and function match

Answer 20

things work well

Question 21

what happens when structure and function do not match

Answer 21

there will be breakdown

Question 22

2 types of material found in skeletal muscle

Answer 22

muscle tissue (contractile)

connective tissue (non-contractile)

Question 23

elasticity

Answer 23

the ability of soft tissue to return to its resting length after a passive stretch

d/t primarily non-contractile tissue

Question 24

contractility

Answer 24

refers to the muscle’s ability to develop tension

d/t contractile tissue

Question 25

irritability

Answer 25

refers to the muscle's ability to respond to chemical, electrical or mechanical stimuli

Question 26

what is a chemical stimuli

Answer 26

ACh @ the neuromuscular junction muscle relaxers

Question 27

what is a electrical stimuli

Answer 27

action potential stim

Question 28

what is a mechanical stimuli

Answer 28

deep tendon reflex

Question 29

what is the morphology of a muscle

Answer 29

refers to how the muscle fibers are aligned with the tendon

Question 30

types of morphology

Answer 30

parallel oblique spiralized

Question 31

what does the alignment of the fibers affect

Answer 31

the physiologic cross-section of the muscle the muscles ability to shorten

Question 32

how is the physiologic cross section measured

Answer 32

transecting each fascicle at a right angle perpendicular to the fibers

Question 33

the larger the physiologic cross section

Answer 33

the greater the ability to produce tension

Question 34

the further a fiber can shorten

Answer 34

the greater ROM it can move the bony lever

Question 35

what are parallel muscles

Answer 35

the fasciculi of the muscle are parallel to the long axis of the muscle

Question 36

how do the fibers run w/in parallel muscles

Answer 36

run the length of the muscle or attached end-to-end

Question 37

how much shortening can a parallel muscle undergo

Answer 37

roughly 50% of its length

Question 38

what do parallel muscles produce

Answer 38

a greater ROM they are good for producing ROM

Question 39

3 types of parallel muscles

Answer 39

quadrilateral strap fusiform

Question 40

quadrilateral

Answer 40

parallel muscle flat, short muscles ex: hyoid muscles and rhomboids

Question 41

strap muscle

Answer 41

parallel muscle the fasciculi are long and extended throughout the length of the muscle

Question 42

how can the fibers lie in a strap muscle

Answer 42

some have very long fibers (ex: sartorious) some have tendinous inscriptions along the way (ex: rectus abdominis)

Question 43

fusiform muscle

Answer 43

parallel muscle most but not all muscle fibers extend throughout the length of the muscle muscle belly is rounded w/ tapering ends fibers curve b/w origin and insertion ex: biceps brachii

Question 44

what are fusiform muscles good at doing

Answer 44

producing ROM

Question 45

oblique muscle

Answer 45

the fiber arrangement is oblique to the muscle's long axis usually more fibers are in oblique muscles fibers tend to be shorter in oblique muscles

Question 46

what happens d/t oblique muscles having a larger # of muscle fibers

Answer 46

only a portion of the force of the muscle goes towards producing motion of the bony lever they are able to transmit a large amount of force to the tendon to which they attach

Question 47

which muscle has a greater physiologic cross-section

Answer 47

oblique muscles increases their ability to produce tension

Question 48

what are oblique muscles good at

Answer 48

producing tension

Question 49

2 types of oblique muscles

Answer 49

triangular pennate

Question 50

triangular muscle

Answer 50

oblique muscle one wide attachment and one narrow attachment ex: pec major and temporalis

Question 51

pennate muscle

Answer 51

the fiber arrangement resembles that found in a feather

Question 52

types of pennate muscles

Answer 52

unipennate bipennate multi-pennate circumpennate

Question 53

unipennate muscle

Answer 53

obliquely set fasciculi fan out on only one side of a central muscle tendon ex: flexor pollicis longus

Question 54

bipennate muscle

Answer 54

fasciculi are obliquely set on both sides of a central tendon ex: rectus femoris, gastrocnemius

Question 55

multi-pennate

Answer 55

the oblique fasciculi converge on several tendons ex: deltoid

Question 56

circumpennate

Answer 56

the fibers surround the centrally located tendon ex: anterior tibilais muscle

Question 57

spiralized muscle

Answer 57

the fibers spiral around the long axis the fibers will wind and unwind

Question 58

what does the strength of a contraction depend on

Answer 58

the size and number of contracting fibers

Question 59

what is maximal strength determined by

Answer 59

the total cross-sectional size of all its fibers

Question 60

parallel muscle cross sectional size

Answer 60

size of all of the fibers is the same as the cross sectional area of the muscle

Question 61

pennate muscle cross sectional size

Answer 61

more muscle fibers the total cross sectional size of the fibers is greater than the cross sectional area of the muscle

Question 62

which muscle would you prefer for force production

Answer 62

oblique muscles

Question 63

which muscle would you prefer for ROM (excursion)

Answer 63

parallel