The Neuromuscular System

What The Neuromuscular System covers

The Neuromuscular System is examined in Component 1, Scientific principles of physical education. It covers muscle fibre types and their characteristics, motor units, recruitment and gradation of contraction, muscle structure and the sliding filament theory and neuromuscular transmission and the response to warming up.

The 4 subtopics

Each one has its own page.

• Muscle fibre types and their characteristicsSlow twitch, fast oxidative glycolytic and fast glycolytic fibres, myoglobin and capillaries, speed and force of contraction, motor neurone size, myosin ATPase, energy stores, and the marathon runner, shot putter and 800 m runner.Open →
• Motor units, recruitment and gradation of contractionMotor units and the all-or-none law, gradation of contraction, wave summation and tetanic contraction, the order of recruitment in a marathon and a vertical jump, the darts player and the scrum, and training recruitment patterns.Open →
• Muscle structure and the sliding filament theoryMuscle structure down to the myofibril, the sarcomere, actin and myosin, tropomyosin and troponin, calcium ions and the sarcoplasmic reticulum, cross-bridges and the power stroke, and the five stages of contraction.Open →
• Neuromuscular transmission and the response to warming upThe central nervous system, the motor neurone and myelin sheath, the neuromuscular junction and motor end plate, acetylcholine and acetylcholinesterase, action potentials, and how a warm-up speeds impulses, reactions and recruitment.Open →

What you need to know

Answer each one before you reveal it.

Take The Neuromuscular System further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Slow twitch fibres vs Fast glycolytic fibres

  Slow twitch fibres: type I muscle cells built for aerobic, fatigue-resistant work. Fast glycolytic fibres: type IIx muscle cells built for maximal force but tiring quickly.

• Actin vs Myosin

  Actin: the thin protein filament carrying binding sites. Myosin: the thick protein filament with heads that form cross-bridges.

• Troponin vs Tropomyosin

  Troponin: the globular protein that binds calcium ions. Tropomyosin: the thread-like strand covering the binding sites on actin.

Questions from this topic

Each one with the model answer underneath.

1. 1

   Name the three types of skeletal muscle fibre.

   Model answer

   The three types are slow twitch (type I), fast oxidative glycolytic (type IIa) and fast glycolytic (type IIx, formerly IIb).

2. 2

   Why are slow twitch fibres suited to endurance work?

   Model answer

   Slow twitch fibres have many mitochondria, much myoglobin and a dense capillary network. Slow twitch fibres produce ATP aerobically and resist fatigue for long periods.

3. 3

   What is myoglobin, and why do slow twitch fibres look red?

   Model answer

   Myoglobin is a protein in muscle that stores oxygen and carries it to the mitochondria. A high myoglobin content and rich blood supply give slow twitch fibres their red colour.

4. 4

   Why do slow twitch fibres have a dense capillary network?

   Model answer

   Many capillaries deliver a steady supply of oxygen and remove carbon dioxide. A constant oxygen supply keeps aerobic respiration going for long periods.

5. 5

   Describe the structure of fast glycolytic fibres.

   Model answer

   Fast glycolytic fibres have a large diameter, few mitochondria and little myoglobin, so they look white. Fast glycolytic fibres have a large store of phosphocreatine.

6. 6

   Why do fast glycolytic fibres fatigue so quickly?

   Model answer

   Fast glycolytic fibres rely on anaerobic ATP production, which uses up their phosphocreatine and glycogen quickly. Lactate and hydrogen ions accumulate and slow contraction.

What is inside Levo

Six ways to work the same material.

The Neuromuscular System revision questions

What does The Neuromuscular System cover in Edexcel A-Level Physical Education?

4 subtopics: muscle fibre types and their characteristics, motor units, recruitment and gradation of contraction, muscle structure and the sliding filament theory and neuromuscular transmission and the response to warming up. Each one has its own page with questions and model answers.

How is The Neuromuscular System organised?

By the Edexcel 9PE0 specification, subtopic by subtopic, so it matches the order you are taught it in.