Muscle Comparative Physiology

Question 1

What two things can’t both be achieved at the same time in a muscle

Answer 1

High force and speed

Question 2

Do longer sarcomeres generate more force?

Answer 2

Yes, but they shorten more slowly

Question 3

What are the two types of skeletal muscle fibres?

Answer 3

Fast twitch and slow twitch

Question 4

Describe fast twitch muscle fibres:

Answer 4

Few mitochondria or blood vessels
Develop greater maximum tension fast but fatigue quickly
Can not replenish ATP for prolonged contraction
Good for power, speed or strength

Question 5

Describe slow twitch muscle fibres:

Answer 5

Contain myoglobin which binds to O2 and many mitochondria and blood vessels 
Reserves of glycogen and fat 
Produces ATP as long as O2 available
Can recycle cross bridges rapidly 
Highly resistant to fatigue

Question 6

How do locusts jump?

Answer 6

By using a ‘catapult’ as en energy store within its hind legs

Question 7

What are synapses clustered together called?

Answer 7

A neuromuscular junction

Question 8

What is maximum force called?

Answer 8

A tetanus

Question 9

What are tonic fibres?

Answer 9

Muscles in vertebrates that receive multi terminal innervartion from a single motor neuron axon
They are inexcitable and do not make spikes

Question 10

What is a motor unit?

Answer 10

A motor neuron plus its fibres

Question 11

Do muscle fibres in insects spike?

Answer 11

No they have several neuromuscular junctions that activates synapses