KINE 433 EXAM 2 NEWEST ACTUAL QUESTIONS

KINE 433 EXAM 2 NEWEST ACTUAL / QUESTIONS

WITH ANSWERS. GRADED A+

ATPase in type I vs Type II fibers - ---Answers---Type I fibers have a slow form of myosin ATPase, whereas type II have a fast form. In response to neural stimulation, ATP is split more rapidly in type II fibers than in type I fibers. As a result, cross bridges cycle more rapidly in type II fibers.

Type I vs Type II - ---Answers---Type I has more mitochondria

Type I has more myoglobin (hence dark color)

Type is slower to fatigue; type IIc would fatigue the fastest (but just keep type IIx in mind)

Sarcoplasmic reticulum type I vs type II - ---Answers---Type II fibers have a more highly developed SR than do type I fibers.Thus, type II fibers are more adept at delivering calcium into the muscle cell when stimuluated. Which is why it is though that type II have faster speed of contraction

Power fiber I vs fiber II - ---Answers---Although the amount of force generated by type II and type I fibers having about the same diameter is about the same, the calculated power of type II fiber is three to five times greater than that of a type I.

• / 3

Motor units fiber I vs fiber II - ---Answers---The alpha motor neuron in a type I motor unit has a smaller cell body and typically innervates a cluster of <300 muscles fibers. In contrast, the alpha motor neuron in a type II motor unit has a larger cell body and innervates > 300 muscle fibers.

Type I Oxidative capacity Glycolytic capacity Contractile spread Fatigue resistance

Motor unit strength - ---Answers---Oxidative: high

Glycolytic capcity: low

Contractile speed: slow

Fatigue resistance: high

Motor unit strength: low

Type IIa Oxidative capacity Glycolytic capacity Contractile spread Fatigue resistance

Motor unit strength - ---Answers---Oxidative capacity:

moderately high

Glycolytic capacity: high

Contractile spread: fast 2 / 3

Fatigue resistance: moderate

Motor unit strength : high

Type IIx Oxidative capacity Glycolytic capacity Contractile spread Fatigue resistance

Motor unit strength - ---Answers---Oxidative capacity: low

Glycolytic capacity: highest

Contractile spread: fast

Fatigue resistance: low

Motor unit strength: high

Type I Fibers per motor neuron Motor neuron size Motor neuron conduction velocity Contraction speed (ms) Type of myosin ATPase Sarcoplasmic reticulum development - ---Answers---Type I

Fibers per motor neuron: <300

Motor neuron size: smaller

Motor neuron conduction : slowervelocity

• / 3