CHAPTER TEN - PHYSIOLOGY

Question 1

What is a motor unit?

Answer 1

It’s made up of a motor neuron. Groups of motor units often work together to coordinate the contractions of a single muscle.

Question 2

What is the all or none principle?

Answer 2

The all-or-none is the principle that the strength by which a nerve or muscle fiber responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the nerve or muscle fiber will give a complete response; otherwise, there is no response.

Question 3

What is a slow twitch muscle? Fast twitch muscle? What types are they each?

Answer 3

They are associated with endurance and postural muscles. What type is it? Type 1

Question 4

What is a fast twitch muscle?

Answer 4

• They are associated with high intensity high velocity twitches. What type is it? Type 2

Question 5

What is a golgi tendon organ?

Answer 5

It responds to high levels of tension, which will cause the muscle to relax.

Question 6

List 4 components of the sliding fi lament theory.

Answer 6

Actin, Myosin, Tropomyosin (troponin and myosin)

Question 7

What are the 3 types of contractions? Describe how they work with force.

Answer 7

1. Concentric action - When the force within the muscle overcomes the resistance against it and the muscle shortens (FORCE PRODUCTION)
2. Isometric action - When the force within the muscle is equal to the resistance placed upon it and there is no movement (STABILIZATION OF FORCE)
3. Eccentric action - When the resistance overcomes the force is being generated by the muscle; although the muscle is contracting it is forced to lengthen with control (also called a “negative” )-
   (FORCE REDUCTION)