Functions of the muscular system:
Muscles must always cross the joints they move, an example of this is the bicep must be attached to the elbow that’s attached to the shoulder. The origin is the bone that remains static and the insertion bone is the bone that moves when the muscle contracts to allow movement. Example: bicep – origin is the scapula and the insertion is the radius.
Muscles are always partly contracting. If they didn’t our bodys would collapse because there would be nothing holding us up.
Our nerves send messages to the brain when they know movement is required then this alerts the muscle fibres making them contract.
All muscles require oxygen and a source of fuel to to allow them to contract, the normal fuel that’s used is glucose or fat. When we are participating in exercise our muscles use the energy judging by the rate of intensity. If we don’t replenish the energy we ae using whilst we are exercising and losing it, our muscles will tire and we will have to reduce the intensity in which we are exercising and eventually stop.
Antagonistic muscle pairs – this is when two muscles work together to create movement.
Agonist is the muscle that shortens to move a joint. This muscle is the the most important in the movement of the joint. The agonists allow the movement so the joint can move. Example – bicep is an agonist when flexing at the elbow.
The antagonist is the muscle that relaxes to allow the agonist to shorten in order to create movement at a joint. All muscles come in pairs so that they can work together to create the movement because as one relaxes the other is working. Example – extending you leg at the knee the hamstring has to relax for quadriceps to work.