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31 terms

Muscular System

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Origin
Part of the muscle attached to the immovable or less movable bone
Insertion
Part attached to the movable bone; insertion moves towards the origin
Flexion
Decrease angle of a joint (hinge joint-knee and elbow)
Extension
Increase angle of a joint (straighten knee or elbow)
Rotation
Movement of a bone around its longitudinal axis (ball&socket joints-shaking head "no")
Abduction
Moving limb away from midline
Adduction
Moving a limb toward the midline
Circumduction
Proximal end of a limb is stationary, distal end moves in a circle combination of a flexion, extension, abduction, and adduction
Dorsiflexion
Lifting the foot so that its superior surface approaches the skin
Plantar flexion
depressing the toes (pointing the foot)
Inversion
Turn the sole medially
Eversion
Turn the sole laterally
Supination
Forearm rotates laterally so palm faces anteriorly; radius and ulna are parallel
Pronation
Forearm rotates medially so palm faces posteriorly; radius and ulna form an X
Opposition
Movement of thumb when touching tips of other fingers on same hand
Prime mover
Muscle that has the major responsibility for causing a particular movement
Antagonists
Muscles that oppose or reverse a movement
Synergists
Help prime movers by producing the same movements
Fixators
Hold a bone still or stabilize the origin of a prime mover so all the tension can be used to move the insertion bone; eg. postural muscles that stabilize the vertebrae
Direction of the muscle fibers
Usually a reference to midline or long axis of a limb (rectus, oblique, transverse)
Relative size of the muscle
Maximus, minimus, longus, medius, brevis
Location of the muscle
Named for bone associated with the muscle (temporalis = temporal bone)
Number of origins
Biceps brachii, triceps brachii
Location of muscle's origin and insertion
Sternocleidomastoid (originates on sternum and clavicle, inserts on mastoid process of temporal bone)
Shape of the muscle
Deltoid means triangular
Action of the muscle
Flexor, extensor, adductor
Circular
concentric circles around the outside body opening (sphincters -eye & mouth)
Convergent
Fascicles converge to single tendon (pectoralis major)
Parallel
Length of fascicle runs parallel to long axis of muscle
Fusiform
Spindle-shaped muscle with expanded belly (biceps brachii)
Pinnate
Short fascicles attach obliquely to central tendon (uni-, bi-, or multi-)