Skeletal Muscle Contraction (Lecture 4) Flashcards Preview

Human Physiology 1 -- Zach H. > Skeletal Muscle Contraction (Lecture 4) > Flashcards

Flashcards in Skeletal Muscle Contraction (Lecture 4) Deck (69)
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61

What is passive tension in the muscle?

How the force of the resistance is measured.

**Thus, the preload stretches the muscle which stretches the sacromere. This preload generates passive tension in the muscle, in which the muscle resists this tension applied to it. This force of the resistance is then measured as passive tension.

62

What is the definition of the afterload in a muscle?

The load the muscle works against.

63

What kind of muscle contraction would occur if the muscle generates more force than the afterload?

An isotonic contraction.

64

Using the term "afterload", construct a sentence that describes an isometric muscle contraction.

If the muscle generates less force than the afterload placed on it, then isometric contraction will occur.

65

What are the 3 types of tension?

1) passive: produced by the preload

2) active: produced by cross-bridge cycling

3) total: sum of active and passive tension

66

When does the cross-bridge cycling start, physiologically?

When free calcium is available and attaches to troponin.

67

True or False:

Contraction is the continuous cycling of cross-bridges.

True

68

True or False:

ATP is required to form the cross-bridge linking to actin but is required to break the link with actin but is required to break the link with actin.

False, ATP is NOT required to form the cross-bridge linking to actin but is required to break the link with actin.

69

What are the two situations that will stop cross-bridge cycling?

1) withdrawal of calcium ion
2) ATP is depleted