Muscular System Chapter 5

Prime Mover

Same as the agonist

Oblique muscle fibers

Shorter, >fibers, >strength

Tone

Slight tension that is present at all times

Neutralizer

contracts to prevent the unwanted motion

Closed kinetic chain

distal-fixed proximal-moves Bench press Sit-ups The upper extremity when one is doing push-ups The upper extremity when one is supported on crutches The lower extremities when one is performing wall slides

Open kinetic chain

distal-free moving proximal-fixed free weights The upper extremity when one is walking and carrying a book bag. The lower extremities when one is swinging from an overhead bar The lower extremity being used to kick a ball

Excursion

distance from max elongation to max shortening

Bipennate muscles

feather central tendon-rectus femoris of the hip

Triangular muscles

flat fan shaped- pectoralis major

Tension

force built up w/ in a muscle when stretch build up tension active tension release

Fusiform muscle

spindle-biceps

Rhomboidal muscle

4 sided flat w/ broad attachments

Eccentric

-Lengthening contraction -Insertion moves away from origin -Isotonic contraction -Muscle contraction slows the pull of gravity on the body segement

Tenodesis

-Passive insufficiency of the finger extensors occurs when the wrist is flexed causing the fingers to extend. -Passive insufficiency of the finger flexors occurs when the wrist is extended causing the fingers to flex.

Concentric

-Shortening contraction -Insertion moves toward origin -Isotonic contraction -Muscle contraction moves the body segment against gravity

Passive insufficiency

-occurs when a muscle cannot be elongated any farther without damage to its fibers -muscle is suppose to relax -ROM

Active insufficiency

-the point when a muscle cannot shorten any further -wrist flexion

Assisting mover

A muscle that is not as effective but does assist in providing that motion is

Extensibility

Ability to be stretched beyond normal resting length

Contractility

Ability to produce tension/shorten

Elasticity

Ability to return to normal length

The sternocleidomastoid muscle typically flexes the head and neck. The mastoid process (on the head) is the insertion and the sternum and clavicle are the origin. Is the origin moving toward the insertion, or is the insertion moving toward the origin during flexion of the head and neck?

Insertion moving toward the origin

What uses the most muscle tissue?

Lengthening

Origin

More Stable. Closer to the trunk.

Insertion

More moveable part. More Distal.

Muscles have origins and insertions. Which is generally proximal?

Origin

When you have worked hard and are short of breath, the sternocleidomastoid helps you to take deeper breaths by lifting the chest. In this case, is the origin moving toward the insertion, or is the insertion moving toward the origin?

Origin is moving toward the insertion

Reversal of muscle action

When origin moves toward insertion.

Agonist

a muscle or group that causes the motion

Stabilizer

a muscle or muscle group that supports or makes firm a part and allows the agonist to work more efficiently.

Antagonist

a muscle that performs the opposite motion of the agonist

Synergist

a muscle that works with one or more other muscles to enhance a particular motion.

Irritable

ability to respond to a stimulus from nerve or electric stimulus.

Strap muscles

long, thin, fibers run entire length of muscle

Parallel muscle fibers

longer, >ROM

Multipennate muscles

many tendons w/ oblique fibers deltoid

Unipennate muscles

one sided feather- flexor polis longus