I predict that muscles do play a part in giving people more strength and grip. However there are also many other factors to consider such as the size of the fingers, palm and basically the whole hand, as with bigger hands you can have a better grip and apply your full strength. I also predict that the male gender of the class will mostly be stronger than the female gender of the class with a few exceptions. I predict that the person with the biggest biceps will have the biggest grip because as they would have bigger biceps muscles they would have more strength and more muscle fibres.
Scientific background and Research on what and how Muscles work:
Muscles are protein- rich tissues that are able to contract by up to ten % of their resting length. A ten % movement is quite small, so bones act as levers to magnify this movement.
Each bone has at least two muscles attached to it- one to pull in one direction and another to pull in the opposite way. This is because muscles can only pull, they cannot push. A contracted muscle can relax, but it cannot push itself back to its original length. It needs another muscle to do that. Pairs of muscles acting in opposite directions are called antagonistic pairs. All muscles must be paired with other muscles to act as antagonists, as shown below.
The muscles we have described so far are skeletal muscles. These are muscles that are attached to bones and are used to move the body. Skeletal muscles can contract powerfully, but get tired easily. They are also controlled by the conscious brain, so you have to decide to run to catch a bus or pick up a cup of coffee.
Another groups of muscles are the smooth muscles of the gut. These muscles contract very powerfully, but do not tire easily and can stay contracted for long periods of time. They are not attached to bones and are not under conscious control.
A third kind of muscle is only found in the heart and is called cardiac muscle. This muscle can contract powerfully and rhythmically and does not get tired. Your heart will beat billions of times during your life without hopefully, ever needing a rest!
In my investigation I will be using the Skeletal muscles and will be investigating them and how they work.
How do muscles contract?
Muscle contraction occurs as actin and myosin myofilaments slide past one another, causing the sarcomas to shorten. Shortening of the sarcoma causes the muscle to shorten. The sliding of actin myofilaments past myosin myofilaments during contraction is called the sliding filament mechanism of muscle contraction. The H zones and I bands shorten during contraction, but the A bands do not change in length.
Skeletal muscle contraction:
1) An action potential travels along an axon to a neuromuscular junction.
2) Acetylcholine is released from the synaptic vesicels of the neurone.
3) 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.
5) Calcium ions are released from the sarcoplasmic reticulum.
6) Calcium ions bind to troponin, associated with actin myofilaments. The binding causes tropmyosin to move into the actin groove, which exposes myosin attachment sites.
7) The heads of myosin myofilaments attach to the actin myofilaments, forming cross bridges.
8) The heads of the myosin myofilaments attach to the actin myofilaments to slide over the surface of the myosin myofilaments.
9) Muscle contraction requires energy. ATP, bound to the myosin heads, is broken down, releasing energy to myosin heads, which is used to supply the energy for movement.
10) Another ATP binds to the myosin head, causing it to release the actin myofilament and the myosin bends back to it’s resting position.
11) As long as calcium remains attached to the troponin, and as long as ATP remains available, the muscle continues to contract and steps 7 through 10 are repeated.
Types of muscle contractions:
Muscle contractions are classified as either isometric or isotonic. In isometric (equal distance) contractions, the amount of tension increases during the contraction process, but the length of the muscle does not change. Isometric contractions are responsible for the constant length of the postural muscles of the body, such as the muscles of the back. On the other hand, in isotonic (equal tension) contractions the amount of tension produced by the muscle is constant during contractions, but the length of the muscle decreases. In my case movements of the arms or fingers are predominall isotonic contractions. However most muscle contractions is a combination of isometric and isotonic contractions in which the muscles shorten some distance and the degree of tension increases.