2.25 Motor SC 2

Question 1

3 muscle fiber types

Answer 1

• Slow twitch
• Fast twitch oxidative-glycolytic
• Fast twitch glycolytic

Question 2

slow twitch aka

Answer 2

S or Type I

Question 3

fast twitch oxidative-glycolytic aka

Answer 3

FOG or Type IIa

Question 4

fast twitch glycolytic aka

Answer 4

FG or Type IIb

Question 5

Where are slow twitch fibers found? How do they fire?

Answer 5

• found in postural muscles (support)

- fire tonically

Question 6

slow twitch: contractile force/ATPase

Answer 6

less contractile force with low myosin ATPase activity

Question 7

slow twitch: metabolism

Answer 7

oxidative metabolism with low glycolytic capacity

Question 8

slow twitch: blood flow

Answer 8

• dense capillary networks

- high blood flow

Question 9

slow twitch: mitochondria, myoglobin

Answer 9

• high mitochondrial density

- high myoglobin content

Question 10

Fast twitch oxidative-glycolytic: contractile force/ATPase

Answer 10

intermediate contractile force and myosin ATPase activity

Question 11

Fast twitch oxidative-glycolytic: metabolism

Answer 11

both oxidative and glycolytic activity

Question 12

Fast twitch oxidative-glycolytic: blood flow

Answer 12

intermediate capillary density and blood flow

Question 13

Fast twitch oxidative-glycolytic: mitochondria, myoglobin

Answer 13

• intermediate mitochondrial density

- intermediate myoglobin content

Question 14

Fast twitch glycolytic: contractile force/ATPase

Answer 14

more contractile force with high myosin ATPase activity

Question 15

Fast twitch glycolytic: metabolism

Answer 15

high glycolytic and low oxidative capacity

Question 16

Fast twitch glycolytic: blood flow

Answer 16

poor capillary networks and low blood flow

Question 17

Fast twitch glycolytic: mitochondria, myoglobin

Answer 17

• low mitochondrial density

- low myoglobin content

Question 18

fast twitch fibers: overall (power, fatigue)

Answer 18

• more powerful muscles
• fatigue a lot faster
• for power movements

Question 19

fatigability: slow twitch

Answer 19

fatigue resistant

Question 20

fatigability: fast twitch oxidative-glycolytic (Type IIa)

Answer 20

intermediate fatigue resistant

Question 21

fatigability: fast twitch glycolytic (Type IIb)

Answer 21

high fatigability

Question 22

motor unit muscle fibers

Answer 22

Motor units contain all of the same type of muscle fibers

Question 23

types of motor units

Answer 23

• Slow twitch units: S
• Fast twitch fatigue resitant units: FR
• Fast twitch fatigable units: FF

Question 24

sizing of motor units with respect to type

Answer 24

Sizing: S

Question 25

recruitment of motor units with respect to type

Answer 25

S
FR
FS

Question 26

pattern of recruitment for motor units

Answer 26

lowest force (or speed) development to greatest force (or speed) development