8: Skeletal Muscle Mechanics

Question 1

Isotonic concentric contraction

Answer 1

picking up a weight

Question 2

Isotonic eccentric contraction

Answer 2

lowering a weight

Question 3

What is the primary source of ATP during a short, high-intensity activity?

Answer 3

creatine posphate

Question 4

What is the primary source of ATP during the first 1.5 minutes of high-intense activity?

Answer 4

glycolysis

Question 5

What is the primary source of ATP during endurance activities?

Answer 5

oxidative phosphorylation

Question 6

Type I slow oxidative muscle fibers

Answer 6

small diameter fibers, resist fatigue (maintaining posture), low myosin-ATPase activity

Question 7

Type IIA fast oxidative-glycolytic muscle fibers

Answer 7

medium diameter fibers, resist fatigue (walking), high myosin-ATPase activity

Question 8

Type IIB fast glycolytic muscle fibers

Answer 8

large diameter fibers, fatigue quickly and used in bursts of strong force (jumping), high mysoin-ATPase activity

Question 9

Which muscle fibers appear white rather than red?

Answer 9

Type IIB fast glycolytic

Question 10

Recruitment

Answer 10

the process of activating different numbers and types of muscle fibers within a fascicle in response to a need

Question 11

Hypertrophy

Answer 11

increase in the cross-sectional diameter of individual fibers

Question 12

Congenital myotonia

Answer 12

mutations in Cl- channels leading to rigid and stiff muscles