Crash Course Muscles 2

Muscles never ________, they always ________.

• push, pull

• contract, relax

• pull, push

• shrink, stretch

The muscles that are mainly responsible for a certain movement are called ________ muscles.

• prime mover

• antagonist

• synergist

• stabilizer

A ________ is a group of muscle fibers that all get their signals from the same motor neuron.

• motor unit

• muscle bundle

• fiber group

• neuron cluster

When a motor unit responds to a single action potential, it’s called a ________.

• twitch

• spasm

• jerk

• pulse

The ________ period is when the stimulus has arrived but no force is being produced.

• latent

• contraction

• relaxation

• refractory

Your brain gets your muscles to increase their force by increasing the ________ with which your motor neurons are firing.

• frequency

• intensity

• duration

• amplitude

Contractions intensify as your motor neurons stimulate more muscle fibers in a process called ________.

• recruitment

• summation

• synchronization

• facilitation

Muscles that work in reverse of a particular movement are called ________ muscles.

• antagonist

• synergist

• prime mover

• stabilizer

Which type of movements change the length of the muscles involved?

• Isometric

• Isotonic

• Static

• Dynamic

Which type of movements do not change the length of the muscles involved?

• Isometric

• Isotonic

• Dynamic

• Aerobic