Muscle movements. Types of muscle contractions We have said so far that muscles will contract or shorten via the sliding filament theory This is true,

Muscle movements

Types of muscle contractions

• We have said so far that muscles will contract or shorten via the sliding filament theory

• This is true, however shortening does not always occur

• Because of this fact we have two types of contractions

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Types of muscle contractions

• The two types of muscle contractions that we can experience are:

• Isotonic contractions -- “same tone”

• Isometric contractions -- “same measurement”

Isotonic Contractions

• Isotonic contractions are contractions that are most familiar to us

• This occurs when the myofilaments are successful in their sliding movements

Isometric contractions

• In Isometric movements the muscles are rapidly gaining tension but not moving

• This type of contraction would occur if you tried to lift a car with out the aid of any tools.

Muscle tone

• Muscle tone is an aspect of skeletal muscle activity that cannot be controlled consciously.

• Muscle tone is the state of continuous partial contractions.

Muscle tone• Muscle tone is the result of different motor units, which are scattered through the muscle, being stimulated by the nervous system in a systematic way

• If muscle tone does not occur, a muscle can be come flaccid and even atrophy

• This is common in people who are paralyzed.

The effect of exercise on muscles

• Muscles health follows a simple pattern; “use it or loose it”

• If we do not use our muscles they will get weaker and atrophy

• Regular exercise will increase muscle size, strength, and endurance.

Muscle Exercise

• Aerobic or endurance types of exercise such as jogging, biking, running, etc will result in stronger more flexible muscles with a greater resistance to fatigue.

Aerobic Exercise • Aerobic exercise strengthens muscles mainly because we are increasing the supply of oxygen to the muscles

• Increased oxygen means more mitochondria for more ATP creation

Aerobic exercise

• Aerobic exercise will also cause the hear to enlarge so that more blood is pumped, increase metabolism, improve digestion, and clear fats from the bloodstream

• Aerobic exercise will not cause muscles to increase in size

Resistance and isometric exercise

• The bulging muscles of a body builder are the result of resistance or isometric exercises

• In isometric exercise you are increasing resistance while the muscles are forced to not contract

Resistance and isometric exercise

• This isometric exercising causes muscles to increase due to enlargement of individual muscle cells ( the cells make more contractile filaments), instead of increase in their number.

• The amount of connective tissue that reinforces the muscle also increases to keep up with muscular demand.