8 Part Code for Naming Muscles

eight criteria

size, shape, orientation of muscle fibers, mechanical action of muscles, number of origins of a muscle (they can have more than one), point of origin and insertion, name of muscle function, muscle’s location

size

maximus or Magnus, minimus, longus, brevis

maximus or magnus

largest muscle in a related group of muscles

minimus

smallest of a group

longus

longest of a group

brevis

shortest of a group

latissimus

largest muscle "in width"

shape

trapezius, deltoid, serrates, platysma

trapezoid ex. trapezius

large distorted rectangle that sits on the upper portion of the back and is rotated 45% so that one corner attaches to each shoulder

delta, triangle, ex deltoid

triangular shaped muscle that sits on the top of the shoulder

serrare, saw tooth ex serratus anterior

muscle that holds your scapula (shoulder blade) to your ribs

flat, plat(eau) ex platysma

muscle is the broad, thin, flat muscle that has its origin across the middle of your chest, runs up across the front and sides of your neck and ends at your chin

Orientation of the Muscle

rectus, oblique, transverse

rectus

identify those muscles whose fibers run parallel to the midline

Oblique

their fibers running at an angle to the midline and perpendicular to each other

transverse

crosswise or perpendicular to the midline of the body

Mechanical action of the muscle

flexor, extensors, pronators, supinator, elevators, depressors, rotators, abductor, adductors, sphincters

Flexor

muscles decrease the angle at a joint

Extensors

muscles that counter flexors. They increase the angle at a joint.

Pronators

turn limbs so that they face downwards or backwards

supinator

counter to a pronator

musculus supinator

is the muscle in your forearm that turns your palm back facing up after you've pronated it down

Levators,

muscles that lift things up

Depressors

are the opposite of levators; they push or pull things downward

Rotators

produce a circular movement around a joint

Abductor

move bones away from a midline in the body

Adductors

move the bones back towards the midline

Sphincters

close openings, as does the anal sphincter.

Number of point of origin

A small number of muscles are named after the number of points of attachment they have at their points of origin.

biceps brachii

two points of origin; your biceps muscle has two branches at its origin

triceps brachii

three points of origin

quadriceps

four points of origin

origin and insertion

smaller number of muscles are named after the parts of the body where they start and end

example of origin and insertion

sternocleidomastoid muscle

sternocleidomastoid muscle originates

both the sternum and clavicle (breastbone and collarbone)

sternocleidomastoid muscle insertion

into the mastoid bone, just below the ear

Named by function

rigorous, masseter, sartorius

risorius

a facial muscle that is crucial for the expressions of smiling and laughter

Masseter

comes from the Greek word for "chew," and that's its function in the human jaw

sartorius

runs from the outer hip, across the thigh, and ends at the inner knee. This muscle pulls the leg up at the knee while simultaneously turning it inward.

Location

temporalis, zygomaticus

Temporalis

named after the temporal bone (your temple) on top of which it is located

zygomaticus

muscles are located over your cheekbone