Skeletal Muscle

Question 1

Skeletal

Answer 1

Voluntary control, striated banding, multi nuclei

Question 2

Smooth

Answer 2

Involuntary control, non-striated banding, single nuclei

Question 3

Cardiac

Answer 3

Involuntary control, striated banding, single nuclei

Question 4

Muscle fiber dimensions

Answer 4

10-100 micrometers thick and 1-30 cm long

Question 5

Surrounds entire muscle

Answer 5

Epimysium

Question 6

Surrounds fasicle

Answer 6

Perimysium

Question 7

Functional unit of contraction

Answer 7

Sarcomere

Question 8

Thick/dark filament in sarcomere

Answer 8

Myosin (15 nm)

Question 9

Thin/light filament in sarcomere

Answer 9

Actin (5 nm)

Question 10

Elastic filaments in sarcomere, bind myosin to z line

Answer 10

Titin

Question 11

Inelastic filaments of sarcomere, twisted around actin

Answer 11

Nebulin

Question 12

Z line

Answer 12

On either end of the sarcomere

Question 13

M line

Answer 13

Middle of sarcomere

Question 14

A band

Answer 14

Myosin band, anisotropic

Question 15

I band

Answer 15

Actin band, isotropic

Question 16

Myofibril

Answer 16

Contractile threads in skeletal muscle

Question 17

Irritability

Answer 17

Muscle responds to stimulus

Question 18

Distensibility

Answer 18

Muscle can be stretched by an outside force

Question 19

Elasticity

Answer 19

Muscle resists elongation

Question 20

Concentric contraction

Answer 20

Muscle shortens under load

Question 21

Eccentric contraction

Answer 21

Muscle lengthens under contraction

Question 22

Isometric contraction

Answer 22

Muscle doesn’t lengthen or shorten

Question 23

Agonist

Answer 23

Major force in the movement

Question 24

Antagonist

Answer 24

Opposes the agonist

Question 25

Synergist

Answer 25

Stabilizes joint around which the movement is occurring (insertion)

Question 26

Fixator

Answer 26

Stabilizes the origin of the agonist (origin)

Question 27

Maximum force is generated when the max number of ___ are formed

Answer 27

Actin-myosin bridges

Question 28

Factors that affect torque output

Answer 28

Force, moment arm (attachment site, insertion angle)

Question 29

Muscle attachment

Answer 29

Further from the joint is better

Question 30

Muscle insertion angle

Answer 30

90 deg is better, but typically less than 45 deg

Question 31

Concentric contraction ___ fibers

Answer 31

Shorten

Question 32

Eccentric contraction ___ fibers

Answer 32

lengthen

Question 33

Surrounds the muscle fiber

Answer 33

Sarcolemma

Question 34

Muscles can conduct an action potential

Answer 34

Conductivity

Question 35

Muscles can shorten and produce a tension between its ends

Answer 35

Contractibility

Question 36

A muscle can return to its resting properties after contraction

Answer 36

Relaxation

Question 37

Opposite of distensibility, muscle resists elongation and returns to its original position after elongation

Answer 37

Elasticity