structure and function of the muscular system Flashcards
name all the muscles in the body (front then back)
deltoid, pectorals, bicep, abdominals, quadriceps, trapezius, triceps, latissimus dorsi, gluteal, hamstring, gastrocnemius
what is the function of the deltoid
used in all movements of the arms. allows abduction, adduction, flexion, extension and rotation of the shoulder
what is the function of pectorals
adducts the arm at the shoulder joint. also used to rotate the arm inwards
what is the function of the bicep
used to cause flexion at the elbow
what is the function of the abdominals
to bend the body forwards at the hips, flexing the vertebrae
what is the function of the quadriceps
to extend (straighten) the knee joint
what is the function of the trapezius
to extend the neck, lifting the head upwards
what is the function of the triceps
to extend (straighten) the arm at the elbow
what is the function of the latissimus dorsi
to adduct the arm at the shoulder. it swings the arm backwards and rotates it inwards
what is the function of the gluteals
to flex (bend) and extend (straighten) the leg at the hip
what is the function of the hamstrings
to straighten the hip and cause flexion (bend) at the knee joint
whats the function of the gastrocnemius
to straighten the leg at the ankle to stand on tip toes or point the toes
how do muscles work
- work across a joint and are attached to the bones by tendons
- work in pairs, contracting and shortening or relaxing and lengthening to create movement
- as one muscle shortens the other lengthens
what is the agonist
creates the movement by contracting and shortening
what is the antagonist
allows movement to take place by relaxing and lengthening
what is the fixator
the muscle that works with others to stabilise the origin of the agonist
what is the synergist
a muscle that assists the agonist in a movement
what is the first antagonist pair in the knee (bend)
hamstring and quadriceps
how do hamstrings and quadriceps work to provide the bending movement at the knee
- hamstring is the agonist, contracting and shortening
- quadriceps is the antagonist, relaxing and lengthening
what is the antagonist pair in the elbow
bicep and triceps
how do bicep and triceps work to provide the straightening movement at the elbow
- triceps is the agonist, contracting and shortening
- bicep is the antagonist, relaxing and lengthening
what is the second antagonistic pair in the knee (straighten)
hamstring and quadriceps
how do the hamstrings and quadriceps provide the straightening movement at the knee
- quadriceps is the agonist, contracting and shortening
- hamstring is the antagonist, relaxing and lengthening
