A&P- Muscle Fibres

Question 1

What do slow twitch muscle fibres rely on a lot of and why?

Answer 1

Oxygenated blood in order to produce energy for muscle contraction.

Question 2

What is Myoglobin?

Answer 2

A protein substance in the cell.

Helps to transport oxygen from Capillaries to Mitochondria.

Question 3

Name the 3 types of muscle fibre.

Answer 3

• Slow Oxidative (type 1)
• Fast Oxidative Glycolytic (type 2a)
• Fast Glycolytic (type 2b)

Question 4

Describe the Slow Oxidative muscle fibre type. Give an example of a sport that would use this fibre type.

Answer 4

• Small amount of tension over a long period of time.
• Fatigue Resistant
• Marathon Runners, Road cyclists,Triathletes,Swimmers

Question 5

Describe the Fast Oxidative Glycolytic muscle fibre type. Give an example of a sport that would use this fibre type.

Answer 5

• Slightly less force than Fast Glycolytic

- More fatigue resistant than Fast Glycolytic

Question 6

Describe the Fast Glycolytic muscle fibre type. Give an example of a sport that would use this fibre type.

Answer 6

• Fatigues easily
• Greatest anaerobic capacity
• Largest force

Question 7

Give the definition of a motor neuron.

Answer 7

A nerve cell which conducts a nerve impulse to a group of muscle fibres.

Question 8

Give the definition of a motor unit.

Answer 8

A motor neuron and the muscle fibres stimulated by its axon.

Question 9

What is Action Potential?

Answer 9

The positive electrical charge inside the nerve and muscle cells which conducts the nerve impulse down the neuron and into the muscle fibre.

Question 10

If there are a large number of motor units that are small in size what movement does this cause?

Answer 10

A Precise Movement

Question 11

If there are a small number of motor units that are large in size what movement does this cause?

Answer 11

A Gross Movement

Question 12

What is the rule of “All or None”?

Answer 12

If one impulse can’t pass through the Synaptic Cleft then neither can the other.
Either both pass through or neither pass through.

Question 13

Describe the journey of an electrical impulse in the motor unit.

Answer 13

• Impulse travels down Axon
• Reaches the Neuromuscular Junction
• If both impulses can pass then they pass through the Synaptic Cleft
• If the tolerance is high enough the impulse reaches the muscle and causes a contraction.