Topic 7 Muscular System: Skeletal Muscle Types

Question 1

a. Slow twitch
b. Lots of myoglobin
c. Lots of mitochondria
d. Aerobic endurance: they split ATP at a slow rate, causing type I fibers to be slow to fatigue but have slow contraction velocity
e. Appear red
f. Small diameter

Answer 1

Type I

Question 2

a. Fast twitch
b. Lots of myoglobin
c. Less endurance than type I: can use aerobic and anaerobic unequally; split ATP at a high rate and contract rapidly; faster to fatigue
d. Appear reddish pink
e. Intermediate in diameter

Answer 2

Type IIA

Question 3

a. Fast twitch
b. Low myoglobin: use glycolysis
c. Lots of glycogen: generates power
d. Split ATP at first rate
e. Fastest to fatigue
f. Appear white
g. Large diameter

Answer 3

Type IIB

Question 4

• Adult human skeletal muscle generally does not undergo mitosis to create new muscle cells (hyperplasia), but it will increase in size (hypertrophy) which results in an increase in: diameter of muscle fibers, number of sarcomeres and mitochondria, and sarcomere length

Answer 4

Note