Chapter 10-muscles Flashcards
Head
Each origin is a head
Origin
Fixed end. Stationary, proximal end of muscle
Insertion
Mobile end. Distal end of muscle attached to the bone undergoing most movement
Belly
Muscle between origin and insertion
Aponeuroses
Tendons that are long and cable like; broad and sheet like
Agonist
A muscle that accomplishes movement. Flexion
Antagonist
Opposite to agonist. Relaxes and stretches
Synergist
Group of muscles that work together to perform movement
Prime mover
Amount a group of synergist, one muscle plays major role in accomplishing movement
Fixators
Muscles that hold one bone in place while more distal bone is moved
Circular muscles
Orbicularis Otis and orbicularis oculi arrange a circle around an opening. Iris of eye, mouth
Convergent muscles
Triangular in shape. Broadly distributed Fascicles that come together at one tendon. Pectoralis major and minor
Parallel muscles
Fascicles lie parallel to one another and long axis of the muscle. Trapezius, rhomboideus, rectus abdominis
Pennate muscle
Fascicles originate from a tendon that runs the length of the entire muscle. Three patterns.
Patterns of pennate muscle
Unipennate, bipennate, multipennate
Unipennate
Fascicles on only one side of tendon palmar interosseus. Semi membranous.
Bipennate
Fascicles on both sides of tendon. Rectus femoris
Multipennate
Fascicles arranged at many places around central tendon. Spread out at angles to many smaller tendons. Deltoid
Fusiform
Fascicles lie parallel to long axis of muscle. Belly of muscle is larger in diameter than ends. Biceps brachii (2 heads) triceps brachii (3 heads)
What geometric shapes can a muscle have?
Triangular, quadrate or rectangular, tres (round) rhombus
Criteria for naming muscles
Location, size, shape, orientation of fasciculi, origin and insertion, number of heads, function.
Lever
Rigid shaft capable of turning a hinge or pivot point (bone)
Fulcrum
Hinge or pivot point. (Joint)
Weight
Resistance.
Pull
Force
Class I lever system
Pull—-fulcrum—-weight
Seesaw
Class II lever system
Pull—- weight in fulcrum
Wheelbarrow
Class III lever system
Fulcrum—-pull—-weight
Hand on top of shovel is fulcrum
Hand closest to shovel head is pull
Shovel head is weight
