Exercise Science Flashcards

Which type of muscle fiber is most resistant to fatigue and relies primarily on oxidative metabolism?

Answer: Type I fibers

Type I (slow-twitch) fibers have many mitochondria and capillaries, so they sustain low-force work for long periods.

According to the length-tension relationship, a muscle produces the most force when it is:

Answer: At its resting length, with optimal actin-myosin overlap

At resting length, actin and myosin overlap enough to form the most cross-bridges.

Which mechanoreceptor senses changes in muscle length and the speed of that change?

Answer: Muscle spindle

Muscle spindles lie parallel to muscle fibers and detect stretch and how fast it happens.

Activating a Golgi tendon organ by holding a static stretch for about 30 seconds produces which effect?

Answer: Autogenic inhibition of the stretched muscle

Golgi tendon organ activation inhibits the muscle it sits in, so the muscle relaxes and lengthens.

The upper trapezius and lower trapezius working with the serratus anterior to upwardly rotate the scapula is an example of a:

Answer: Force-couple relationship

A force-couple is when muscles pull in different directions together to produce one movement around a joint.

Which plane of motion divides the body into left and right halves and includes flexion and extension?

Answer: Sagittal plane

Sagittal-plane movements such as flexion and extension happen around a frontal (coronal) axis.

Altered reciprocal inhibition happens when:

Answer: A tight agonist reduces neural drive to its functional antagonist

A tight, overactive muscle sends less neural drive to its opposing muscle, which leaves it underactive.