remember remember muscular system

Here is a concise revision guide for the anatomy and physiology of the muscular system

CHARACTERISTICS

Excitability
Contractability
Extensibility
Elasticity

MUSCLE CONTRACTION

Muscle works by shortening
Each individual muscle fibre contracts fully
Fibres slide over each other to make muscle length shorter

ORIGIN AND INSERTION

Origin is where the muscle starts
Insertion is where the muscle ends
Muscle usually works by moving insertion towards origin

MUSCLE ACTIONS

Muscles work by pulling not pushing
So when one muscle shortens / contracts another must lengthen / relax
Muscles therefore work in pairs
When the prime mover / agonist contracts the antagonist relaxes
Muscles which stabilise joints are known as synergists
Sphincters are muscles surrounding orifices

ENERGY / WASTE PRODUCTS

Energy for muscle work comes from oxygen, glycogen and fat
Of energy used 30% produces work and 70% produces heat and waste products
Waste products are carbon dioxide, lactic acid, heat and water

MUSCLE TONE

Muscles are always in state of slight contraction called muscle tone
Function of muscle tone

Maintain posture
Works metabolic pump
Keeps body in state of readiness

MUSCLE FATIGUE

Continuous stimulation of muscle leads to weakening contractions when muscle no longer responds

MUSCLE TENSION

Increase in normal muscle tone

MUSCLE SORENESS

Waste products build up until fibres can no longer slide over each other

For a much more in depth lesson on muscles.

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