Muscle Video 2

Which of the following is the smallest skeletal muscle in the human body?

• Sartorius

• Gluteus Maximus

• Stapedius

• Rectus Femoris

What is the fundamental principle governing how skeletal muscles move bones?

• Muscles always push bones away from their origin.

• Muscles can both push and pull bones depending on the movement.

• Muscles always pull their insertion point towards their origin.

• Muscles extend themselves beyond their resting state to create movement.

In the context of muscle movement, what is the role of an antagonist muscle?

• It is the primary muscle responsible for producing a specific movement.

• It helps the prime mover by lending extra force or stabilizing joints.

• It works in reverse of a particular movement, often by relaxing or stretching.

• It immobilizes the origin bone to make the prime mover more effective.

What defines a motor unit?

• A single muscle fiber that contracts independently.

• A group of muscle fibers that receive signals from multiple motor neurons.

• A group of muscle fibers that all get their signals from the same, single motor neuron.

• The entire muscle, including all its fibers and neurons.

What two factors primarily influence graded muscle responses?

• Temperature and pH levels

• Frequency and strength of stimulation

• Muscle fiber type and age

• Blood flow and oxygen supply

What occurs when successive muscle twitches happen so closely together that the muscle does not fully relax between stimuli, leading to increased force?

• Muscle fatigue

• Isometric contraction

• Temporal summation

• Recruitment

What is the primary reason that vigorous muscle activity cannot be maintained indefinitely?

• Accumulation of lactic acid

• Depletion of the finite supply of ATP

• Damage to muscle fibers

• Insufficient calcium release

When increasing the strength of a muscle contraction, which motor units are typically activated first according to the size principle?

• The largest motor units with the biggest muscle fibers.

• Motor units with an equal mix of small and large fibers.

• The smallest motor units with the smallest muscle fibers.

• Randomly selected motor units regardless of size.