Anatomy exam ch 11

Origin

Origin

The attachment to the stationary bone

Insertion

The attachment to the moveable bone

First-class levers

Fulcrum between the effort and the load

Second-class lever

Load between the fulcrum and the effort

Third-class levers

Effort is between the fulcrum and the load

Head moves back and forth on vertebral column

Example of a first class lever

Raising leg on toes

Example of second class lever

Flexing elbow

Example of third class lever

Parallel Fascicle

Fascicles parallel to longitudinal axis of muscle' terminate at either end in flat tendons

Fusiform Fascicle

Fascicles nearly parallel to longitudinal axis of muscle; terminate in flat tendons; muscle tapers towards tendons, where diameter is less than at belly

Circular Fascicle

Fascicles in concentric circular arrangements form sphincter muscles that enclose an orifice

Triangular Fascicle

Fascicles spread over broad area converge at thick central tendon; gives muscle a triangular appearance

Pennate muscle

Short fascicles in relation to total muscle length; tendon extends nearly entire length of muscle

Unipennate Fascicle

Fascicles arranged on only one side of tendon

Bipennate Fascicle

Fascicles arranged on both sides of centrally positioned tendons

Multipennate Fascicles

Fascicles attach obliquely from many directions to several tendons

Prime mover (agonist)

Contracts to cause an action

Antagonist

Opposes the action of the prime mover

Synergists

Prevent unwanted movement or otherwise aid the movement (insertion site)

Fixator

Stabilizes the origin so the agonist can achieve maximum and effective contraction

Rectus

Parallel to midline

Transverse

Perpendicular to midline

Oblique

Diagonal to midline

Maximus

Largest

Minimus

Smallest

Longus

Long

Brevis

Short

Latissimus

Widest

Longissimus

Longest

Magnus

Large

Major

Larger

Minor

Smaller

Vastus

Huge

Deltoid

Triangular

Trapezius

Trapezoid

Serratus

Saw-toothed

Rhomboid

Diamond-shaped

Orbicularis

Circular

Pectinate

Comblike

Piriformis

Pear-shaped

Platys

Flat

Quadratus

Square, four sided

Gracilis

Slender

Flexor

Decreases joint angle

Extensor

Increases joint angle

Abductor

Moves bone away from midline

Adductor

Moves bone closer to midline

Levator

Raises or elevates body part

Depressor

Lowers or depresses body part

Supinator

Turns palm anteriorly

Pronator

Turns palm posteriorly

Sphincter

Decreases size of an opening

Tensor

Makes body part rigid

Rotator

Rotates bone around longitudinal axis

Biceps

Two origins

Triceps

Three origins

Quadriceps

Four origins

Muscles of the rotator cuff

Supraspinatus, infraspinatus, teres minor, subscapularis

Muscle compartments of the thigh

Medial (adductors), anterior (extensors), posterior (flexors)