Axial Musculature With Action, Origin, And Insertion

Front 1

Occipitofrontalis

Back 1

Covers the skull and the two bellies are attached by the epicranial aponeurosis. The two bellies are the frontal belly and the occipital belly.

Front 2

Auricularis

Back 2

There are three separate muscles within this group: Anterior, Superior, and Posterior. Responsible for the movement of the ear and attach to the epicranial aponeurosis.

Front 3

Orbicularis Oculi

Back 3

The muscle around the eye/orbit. The action of this muscle is to close the eye.

Front 4

Corrugators Supercilii

Back 4

This extends from the corner of the eyebrow to the procerus.

Action: Pulls skin inferiorly and medially;wrinkles the brow.

Front 5

Orbicularis Oris

Back 5

Around the mouth

Action: Compresses and purses lips

Front 6

Buccinator

Back 6

From the corner of the lips angled to the ear. Deep bipennate muscle

Action:Compresses the cheeks

Front 7

Zygomaticus Major

Back 7

Below the minor. From the corner of the lip to the zygomatic bone.

Action: Retracts and elevates corner of mouth (smile)

Front 8

Zygomaticus Minor

Back 8

Above the major. From the top of the lip to the zygomatic bone.

Action: Retracts and elevates upper lip

Front 9

Risorius

Back 9

In the horizontal plane at the corner of the mouth.

Action: Draws corner of the mouth laterally.

Front 10

Mentalis

Back 10

On the chin. Elevates, everts, and protrudes lower lip.

Front 11

Procerus

Back 11

Between the eyes.

Action: Draws medial angle of eyebrows inferiorly

Front 12

Nasalis

Back 12

Over the bridge of the nose and has horizontal fibers.

Action: Compresses bridge, depresses tip of nose, elevates corner of nostrils.

Front 13

Masseter

Back 13

From the zygomatic arch to the angle of the mandible.

Action: Closes jaw;assists in protraction, retraction, and side to side movement of the mandible

Front 14

Temporalis

Back 14

Goes through the zygomatic process and attaches to the coronoid process.

Action: Closes jaw; assists in retracting and moving mandible side to side

Front 15

Sternocleidomastoid

Back 15

Under the platysma. Visible if turn head to the side.

Origin: Sternal head originates from manubrium; clavicular head originates from the sternal end of the clavicle

Insertion: Mastoid process of temporal bone

Action: Singularly: Tilt the head to the side; rotation of the head

Together: Flex the neck; protracts head; aids in inspiration

Front 16

Scalenes

Back 16

Attach to the transverse processes of C2-C7 to the either 1st or 2nd rib. 3 of them: Anterior (1st), middle (1st), and posterior (2nd).

Action: Flexes and side bends the neck. Elevates ribs 1 and 2 in inspiration.

Front 17

Serratus posterior inferior

Back 17

An Intermediate extrinsic back muscle.

Action: Depresses ribs, aids in expiration

Front 18

Platysma

Back 18

From the mandible to the deep fascia of the chest.

Action: Tenses skin of neck, depresses the mandible

Front 19

Serratus posterior superior

Back 19

An Intermediate extrinsic back muscle.

Action: Elevates ribs, aids in inspiration

Front 20

Splenius Capitis

Back 20

Part of the superficial intrinsic back muscle. Lateral to semispinalis capitis.

Action: Together they extend the neck; alone they rotate and laterally flex the neck.

Front 21

Erector Spinae

Back 21

Part of the intermediate intrinsic back muscle. 3 parts we need to know: Iliocostalis thoracis (lateral), Longissismus thoracis (middle), and Spinalis thoracis (medial).

Action: As a whole extend all of the vertebral spine, elevates and depresses ribs.

Front 22

Semispinalis capitis

Back 22

Deep intrinsic back muscle. Medial to the splenius capitis.

Action: Primarily stabilization and delicate adjustment pf vertebrae. Slight extension and rotation of vertebrae.

Front 23

Multifidus

Back 23

Deep intrinsic back muscles. These are intervertebral, each spanning 3-4 vertebrae.

Action: Extends vertebral column and rotates toward opposite side.

Front 24

Rotatores

Back 24

Deep intrinsic back muscle. Similar to the Multifidus, but only span 1-2 vertebrae.

Action: Extends vertebral column and rotates toward the opposite side

Front 25

Intertransverarii

Back 25

Deep intrinsic back muscle. Spans between the transverse processes.

Action: Lateral flexion of the vertebral column

Front 26

Quadratus Lumborum

Back 26

Spinal Flexor.

Origin: iliac crest

Insertion: 12th rib and the transverse process of lumbar vertebrae

Action: Together they depress the ribs, each produce lateral flexion of vertebral column; fixes floating ribs during forced exhalation; stabilizes diaphragm during inhalation

Front 27

External Intercostals

Back 27

Slanted upwards from midline like \\\|///.

Action: Elevate ribs

Front 28

Internal Intercostals

Back 28

Slant down from midline. ///|\\\

Action: Depresses ribs

Front 29

Transversus Thoracis

Back 29

Near the inside of the sternum to the border of the costal cartilage. Has minimal significance.

Action: Depresses ribs

Front 30

Rectus Abdominis

Back 30

Middle of the Abdominal section. Has a rectus sheath overtop of it. Tendinous inscriptions are the horizontal tendon, and the linea alba is the vertical tendon.

Origin: Superior surface of the pubis

Insertion: Costal Cartilage of ribs 5-7 and the xiphoid process of the sternum.

Action: Flexes the vertebral column and acts to resist vertebral motion.

Front 31

Pyramidalis

Back 31

This is located at the base of the rectus abdominis. Tenses the linea alba

Front 32

External oblique

Back 32

Side of the rectus abdominis. Fibers are going upward from the midline \\\|///.

Origin: External and inferior borders of ribs 5-12

Insertion: External oblique aponeurosis extending to the linea alba and the iliac crest.

Action: Depresses ribs; flexes, laterally rotates vertebral column to the opposite side.

Front 33

Internal oblique

Back 33

Underneath the external oblique. Fibers are going downward from the midline ///|\\\.

Origin: Thoraculumbar fascia, inguinal ligament, and iliac crest

Insertion: Inferior surface of ribs 9-12 and associated costal cartilage, linea alba, and pubis

Action: Depresses Ribs; flexes, laterally rotates vertebral column to the same side

Front 34

Transverse abdominis

Back 34

Underneath all the other abdominal muscles.

Origin: Cartilages of ribs 6-12, iliac crest, and thoraculumbar fascia.

Insertion: Linea alba and pubis

Action: Compresses the abdomen

Front 35

Diaphragm

Back 35

Contraction expands the thoracic cavity, compresses abdominopelvic cavity.

Front 36

Muscles in the Intermediate extrinsic back

Back 36

Serratus Posterior Superior and Inferior.(2 on each side)

Front 37

Muscles in the Superficial intrinsic back

Back 37

Splenius Capitis

Front 38

Muscles in the intermediate intrinsic back

Back 38

Erector Spinae (Iliocostalis thoracis (lateral), Longissismus thoracis (middle), and Spinalis thoracis (medial))

Front 39

Muscles in the deep intrinsic back

Back 39

Semispinalis capitis, multifidus, rotatores, and intertransversarii