Lecture 19 Flashcards

1
Q

What is MTC stand for

A

Muscle tendon complex

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2
Q

What can a MTC only do

A

Pull

Cannot push

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3
Q

Force developed in MTC attempts to do what

A

Bring the two insertion points closer together

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4
Q

When hopping vertically, the propulsive phase (plantar flexion):

MTC is…

Whole body PE and KE…

Force generated by MTC and displacement are…

MTC is doing…

Concentric or Eccentric action?

Force produced by MTC greater or lesser than External force as it ______

A

Shortening

Increases

In the same direction

Positive work

Concentric action

Greater, Shortens

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5
Q

When hopping vertically, the braking phase (dorsi flexion):

MTC is…

Whole body PE and KE…

Force generated by MTC and displacement are…

MTC is doing…

Concentric or Eccentric action?

Force produced by MTC greater or lesser than External force as it ______

A

Lengthening

Decreases

Are in opposite directions

Negative work

Eccentric action

Lesser, Lengthens

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6
Q

MTC concentric action is where:

F MTC is…

Change in displacement is…

A

F MTC > F external

Change in displacement is in same direction as F MTC

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7
Q

MTC eccentric action is where:

F MTC is…

Change in displacement is…

A

F MTC < F External

Change in displacement is in opposite direction as F MTC

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8
Q

MTC Isometric action is where:

F MTC is…

Change in displacement is…

A

F MTC = F External

No displacement = 0

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9
Q

The major contractile unit of a muscle is the…

A

Sacromere

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10
Q

Contractile proteins are

A

Actin

Myosin

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11
Q

What does sacromere shortening result from

A

Relative movement of myosin which pulls actin to the center

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12
Q

What does muscle architecture refer to

A

How fibers of a muscle are arranged relative to the vector of the force generation

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13
Q

Parallel is in what axis

A

X axis

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14
Q

Pennate is what…

A

Diagonal from x axis

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15
Q

What are the factors that influence MTC force producing capacity

A

Cross sectional area

MTC length

Type of action

Velocity

Fiber type

Recruitment

Time history of activation

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16
Q

Will a bigger muscle (bigger volume) produce more force

A

Not always

Depends on physiological cross sectional area

17
Q

The physiological cross sectional area is located

A

Perpendicular to the fibers

18
Q

What physiological cross sectional area is larger in

Longitudinal muslce (5cm)

Pennate muscle (5.77cm)

A

???

19
Q

Force length relationship:

Ascending phase

A

Large overlap between actin and myosin heads

Small number of cross bridges that can be formed

When length increases
More cross bridges can be formed

20
Q

Force length relationship:

Resting legnth, plateau phase

A

Optimal number of actin myosin interactions

21
Q

Force length relationship:

Descending phase

A

Actin and myosin are too far apart

Decrease number of cross bridges that can be formed