Ch 7: Muscle Structure Flashcards Preview

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Flashcards in Ch 7: Muscle Structure Deck (15)
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1
Q

2 ways Origin and Insertion is defined

A

Anatomically

Mechanically

2
Q

Anatomical definition to insertion and origin

A

Origin: proximal
Insertion: distal

3
Q

Mechanical definition for origins and insertion

A

Origin: stable part
Insertion: moveable part

4
Q

The movement a muscle produces is a result of …

A

Type of joint

Line of pull

5
Q

What does the angle of attachment have to do with strength?

A

There is a best mechanical advantage. [ex: biceps at 90°]

6
Q

How is the line of pull dynamic?

A

Depends on 1. Starting position 2. Anatomical pulleys

7
Q

7 fiber arrangement classifications

A
  1. longitudinal
  2. Quadrilateral
  3. Triangular
  4. Fusiform
  5. Pennate
  6. Bipennate
  7. Multipennate
8
Q

What sarcomere arrangement results in greater force?

A

Bipennate/multipennate: more sarcomeres pulling

9
Q

What sarcomere arrangement results in greater shortening velocity?

A

Longitudinal: more displacement = more velocity

10
Q

What is the percentage rest length that muscles:
Have the least strength?
Have the most strength?
Reason?

A

Least: 60% and 160%+
-too much or too little cross bridge overlap

Most: 120%
-goldilocks zone for cross bridge overlap

11
Q

What happens as a muscle is stretched?

A

Titin provides recoil to bring sarcomere back to neutral. As the muscle is stretched, tension is created.

12
Q

What is the relationship between force and velocity in a trained and untrained person?

A

Force produced by a trained person is greater, no change in overall velocity.
-The velocity of a trained person is greater than untrained when moving at the same force.

13
Q

Describe the force-velocity relationship during eccentric movement. Example?

A

Arm extending when weight is too heavy to even maintain position.
Muscles are lengthening because weight it too heavy
Force produced highest, velocity % is low, increases with weight.

14
Q

Describe the force-velocity relationship during metric contraction. Example?

A

Arm maintaining position with weight too heavy to lift.
Muscles not shortening or lengthening.
Moderate amount of force with no velocity in either direction.

15
Q

Describe the force-velocity relationship during concentric movement. Example?

A

Arms can move the weight - low weight.

Muscles shorten, lighter the load, less force required, more velocity created.