• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Muscle fibre types.

Extracts from this document...


Laura Cwiklinski January 2002 Portfolio Piece Muscle Fibre Types There are three different types of muscle fibre found within the body. Each has a specific set of characteristics that determine the type of activity that a person will be much more able and capable of performing. The three types of muscle found within the body are: -Slow oxidative fibres (SO) -Fast oxidative glycolytic fibres (FOG) -Fast glycolytic fibres (FG) Every muscle contains all three types but not in equal proportions. You will only find one fibre in any one given motor unit. Type 1: Slow Oxidative Fibres The nerve impulse travels slowly to the muscle fibre because the myelin sheath is thin. Slow twitch fibres do not produce as much force as fast twitch fibres. They can however, have high levels of endurance. Slow twitch fibres are far more suited to aerobic work. They contain mitochondria and myoglobin, and have lots of blood capillaries. They have necessary enzymes to help break down fat and carbohydrate to carbon dioxide and water. It is a slower process than releasing energy anaerobically but it doesn't produce any fatiguing by-products. ...read more.


This means that less reactions are able to take place between the troponin and the calcium due to less calcium ions being present. This results in low contractile speed, which means that movement is slower, hence the name slow witch fibre. In terms of function, a slow oxidative fibre has a high aerobic capacity. This is due to the large number of mitochondria found in this muscle type. Mitochondria are the site at which aerobic respiration takes place in a cell, and provide energy for muscle contraction via ATP. This means that the anaerobic capacity of this fibre is low. The fatigue resistance is very high because they have a high aerobic capacity. This means that lactic acid that may accumulate in the muscle can be oxidised to prevent fatigue. However, the strength of a motor unit is low which means that the force produced is not as high as the force found in fast twitch fibres. Fast oxidative glycolytic fibres contain between 300 and 800 fibres per motor neurone. This is because the size of the motor neurone is large. The type of myosin ATPase is fast which results in the rapid breakdown and release of energy. ...read more.


The contractile speed found in a fast glycolytic fibre is fast because the motor neurones are large and are able to exert a large force. The fatigue resistance is low because there are not many mitochondria found in the fibre but energy is rapidly released, so the muscle tires quickly. However, the strength of each motor unit is high. This is because the neurone is able to activate a greater number of muscle fibres, meaning that each motor unit is very strong and can create a high force. "The distribution of muscle fibre type can help to determine the type of sporting activity an individual is most suited to". In terms of my sport, long jump fast twitch muscle fibres dominate. This is because this activity requires large amounts of instant energy, lasting for only a few seconds, with full recovery between repetitions. This is due to the explosive nature of the event. The movements are rapid and require maximum force with precision timing. One reason for this is that an adaption occurs in the stores of ATP and PC within the muscle cell sarcoplasm are increased. This causes more energy to be available more rapidly and increases the maximum possible peak power output of a muscle. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Anatomy & Physiology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Anatomy & Physiology essays

  1. A level Project, Personal Exercise Program on Netball.

    Then they jump as high as they can and mark the wall with the chalk/their finger. The distance between each mark is the given distance jumped. Reliability would depend upon how strict the test is conducted and the individual's level of motivation to perform the test.

  2. Free essay

    Body In Action

    These are freely movable joints. Most of the joints in the body are of the synovial type. The following are the main characteristics of a synovial joint: * The ends of the bones are covered with a layer of smooth hyaline cartilage, called articular cartilage in the joint regions. This reduces fricton at the point.

  1. Physiology Within Sport

    and the air they were inhaling was enough to recover from the exercise. From looking at the tidal volume, this also increased as expected by 0.48 L this is an indication that the athlete required large amounts of oxygen per each breath, this also explains why the breath rate was

  2. Movement within the Body and the Cardiovascular System

    Although difficult to do the muscle does gain even strength through out. It is also the most efficient way to improve muscle strength. Equipment for this type of training is very expensive so most gyms cannot afford to buy it especially public sector gyms.

  1. I am going to investigate the relationship between the size of our biceps muscle ...

    Acetylcholine diffuses across the synaptic cleft and binds to receptor molecules in the muscle cell membrane. 4) Sodium ions diffuse into the muscle cell, initiating an action potential in the muscle cell. The action potential travels along the sarcoma and T tubules to the sarcoplasmic reticulum.

  2. Different Types of Mental Training

    things that directly affect sports performance) and being able to close out factors that don't directly affect the sport performance (e.g. crowd noise and banners). By imagining what you want to achieve and what you need to be able to do to achieve it you can prevent your attention from focusing on irreverent aspects and focus on relevant aspects instead.

  1. Body In Action

    Their walls are less muscular than those of the arteries, but gradually increase in thickness as they approach the heart. The vena cava is the largest vein, which enters the heart through the right atrium. The smallest veins are called venules, which transport the blood from the capillaries into the veins.

  2. Planning, performing and evaluating a Personal Exercise Program (PEP)

    and prepare the muscle quickly for a sequential contraction of equal force' - When warming up and stretching, you are increasing the length of your muscles, this prevents people from sustaining injuries, this is needed in many sports because if a sudden change of direction occurs and the muscle is

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work