Muscular System

Planter Flexion

Lifting of the toes

Dorsi Flexion

Lifting the toes

Slow Twitch Fibres

The nervous system detects when the activity is slow and prolonged, used for endurance activities, they can contract many times and stay efficient over long periods of time, they have good oxygen supply so meaning they take longer to tire out (Eg: slow switch fibres are used in jogging)

The Origin

The origin is attached to the non-moving end of the bone

Skeletal Muscle

Attached to bones on its ends via tendons

Involuntary Muscles`

Automatic, smooth muscles that aren't controlled (Eg: blood vessels, intestines digesting food, heart pumping blood, digestion, excretion, circulation)

Voluntary Muscles

Controlled muscles that are consciously working, the most common muscles, strained, keeps the body upright and assists with movement

Muscle Contractions

A shortening or tensing of a muscle which causes movement

Concentric Contractions

Concentric contractions take place when the agonist muscle contracts/shortens and the antagonist muscle relaxes/lengthens (e.g. hitting a tennis ball)

Eccentric Contractions

Eccentric contractions take place when the antagonist muscle contracts/shortens and the agonist muscle lengthens/relaxes

Extension

If the angle at the joint is getting bigger then the movement is extension

Flexion

If the angle of the joint is getting smaller then the movement in flexion

Rotation

If the movement is around the the movement is rotation

Abduction

If the movement is moving away from the body then the movement is abduction

Adduction

If the movement is towards the body then the movement is adduction

Cardiac Muscles

Involuntary muscles that never rest (Eg: the heart)

Isometric Contractions

Isometric contractions take place when there is a pulling or pushing force but both of the muscles in the antagonistic pair stay in a fixed position (Eg: planks, holding push ups, rings in gymnastics)

The Insertion

The insertion is attached to the moving end of the bone

Agonist (the prime mover)

The main mover in the antagonistic pair which is causing the movement to happen

Antagonist

The muscle in the antagonistic pair that does the least work, relaxing while the other muscle contracts (against the movement)

Antagonistic Pair

Two muscles that work together to create movement (E.g. bicep and tricep, hamstring and quadricep)

Fast Twitch Fibres

When the nervous system decides an activity/event requires short bursts of energy, they contract fast and produce powerful action, they have limited oxygen supply and tire quickly (Eg: fast twitch fibres are used in sprinting)

Tendons

White chords that are very flexible and very strong (muscles are attached to skeletal bones by tendons)