Chapter 5: Muscle Structure and Function

Question 1

In a bicep curl, the biceps brachii is the prime mover (a.k.a. the ________ )

Answer 1

Agonist

Question 2

During a bicep curl, what is the antagonist that must relax to allow the biceps brachii to perform the movement?

Answer 2

The triceps brachii

Question 3

During a bicep curl the brachialis muscle assists the biceps brachii, performing this role.
The pectoralis major keeps the shoulder stable, performing this role.

Answer 3

Brachialis = synergist
Pectoralis major = fixator

Question 4

What are the different levels that make up a muscle?

Answer 4

Myofibrils ~> Muscle fibres (wrapped in sarcolemma) ~> Muscle fibre bundle ~> Muscle belly

Question 5

Actin (pulls/moves) = ___ band
Myosin (pulls/moves) = ___ band

Answer 5

Actin (moves) = I band
Myosin (pulls) = A band

Question 6

True or false: fast twitch muscle fibres use the aerobic system more than slow twitch muscle fibres in order to supply more oxygen to increase power

Answer 6

False. Fast twitch do NOT use the aerobic system as much as slow twitch muscles

Question 7

True or false: each muscle fibre is activated by one neuron, but neurons may activate multiple fibres

Answer 7

True

Question 8

What is intramuscular coordination?

Answer 8

The capacity to activate different motor units simultaneously. Trained athletes have higher capacities than untrained people