work automaticaly and constantly
only found in the walls of the heart
muscles that you cannot control
found in the walls of the intestines and in the blood vessels
they have to keep contracting to allow crucial body functions to continue
also known as smooth muscles
the attachment of muscles
voulntary muscles are attached to the skeleton by TENDONS.
The point where the msucle is attached to he fixed/stable bone is called the origin.
The point where the muscle is atttached to the moving bones is valled the insertion.
skeletal muscles/voluntary muscles
Make up the majority of muscles in the body.
Attached to the skeleton.
They are under our conscious control and move through conscious effort.
How muscles work
in order to enable a pulling movement in both directions muscles need to work in pairs.
the muscle which is contracting os known as the prime mover or agonist
the muscle which is relaxing is known as the antagonist
antagonistic muscle groups
muscle that work in pairs are said to work antagonistically
bending the arm at the elbow is an example of flexion taking place
the muscle responsible for flexion at the elbow is the bicep
the bicep is the prime mover or the agonist as it produces the desired joint movement.
in order for the muscle to shorten when contracting the tricep muscle must lengthen
the tricep in this instance is known as the antagonist since the action is opposite the bicep
separate muscle categories
flexors - muscles that bend limbs at a joint by contracting
extensors - the muscles that work with and against the flexors and straighten a limb at a joint by contracting
adductors - the muscles that move a limb towards the body
abductors - the muscles that move a limb away from the body
there are two types of muscular contrations
when muscles contract but stay in a fixed position niether shortening or lenthening
example - scrum in rugby
- tug of war
when muscles contract and work over a range of movement
muscles contract with visible movement
there are two types
- concentric - shorten
- ecentric - lengthen
concentric contraction and ecentric
concentric - when the muscle shortens. It also tends to bulge e.g. Biceps in the arms
ecentric - when the muscles gradually lengthens and returns to its normal length and shape
short term effects of exercise on the muscular sys
working muscles produce heat
lactid acid production during anearobic exercise causes cramp
cardiac muscle works harder
more oxygen is needed in the working muscles
muscles contract and relax
muscles becoem fatigued as the ability to use oxygen becomes less effecient
long term effects of exercise and on the muscular
muscles will incresse in size and strenth as a result of regular exercise. An increase in muscle size is called hypertrophy
regular exercise willl increas the muscular systems resistance to fatigue
when muscle looses its size due to inactactivity or injury it is called atrophy