A&P Lab 10: Facial Muscles & Anterior Axial Muscles

The Muscular System

  Frontalis

•Origin: epicranial aponeurosis

•Insertion: skin of eyebrows

•Raises Eyebrows, wrinkles forehead

Occipitalis

•Origin: occipital and temporal bones

•Insertion: epicranial aponeurosis

•Pulls scalp backwards

Orbicularis oculi

•Origin: maxilla and frontal bone

•Insertion: skin around the eye

Action:

•Closes the eye (blinking)

Orbicularis Oris

•Origin: other muscles near the mouth

•Insertion: skin around the mouth

Action:

•Closes and protrudes (puckers) the lips

Zygomaticus major

•Origin: zygomatic Bone

•Insertion: skin and muscles at the corner of the mouth

Action:

•Elevates the corner of the mouth (smiling)

Zygomaticus minor

•Origin: zygomatic Bone

•Insertion: skin and muscles of the corner of the mouth

•Medial to zygomaticus major

Action:

Elevates the corner of the mouth (smiling)

Masseter

•Origin: zygomatic arch

•Insertion: lateral surface of the ramus of mandible

Action:

•Elevates and protracts mandible

Buccinator

•Origin: alveolar processes of the maxilla and mandible

•Insertion: next to orbicularis oris

Action:

Compresses the cheeks

Temporalis

•Origin: temporal fossa

•Insertion*: coronoid process of mandible

Action:

•Elevates and retracts the mandible

Sternocleidomastoid

•Origin: sternum & clavicle

•Insertion*: mastoid process of temporal bone

Action:

•Flexes and laterally rotates head

Splenius capitis

•Origin: spinous process of C7 & upper thoracic vertebrae

•Insertion: occipital bone and mastoid process

• Actions: Extend or hyperextend head, head rotation and lateral tilting when only one is activated

Pectoralis major

•Origin: clavicle, sternum, and costal cartilages of upper ribs

•Insertion*: intertubercular sulcus of humerus, greater tubercle

Action:

•Adducts and rotates arm medially

Pectoralis minor

•Origin: anterior surface of ribs 3-5

•Insertion*: coracoid process of the scapula

Action:

•Depresses and protracts the scapula

•Elevates ribs for forceful inhalation

Deltoid

•Origin: acromion process & spine of scapula, clavicle

•Insertion: deltoid tuberosity of humerus

Action:

•Abducts arm

•flexes and extends shoulder

External Intercostals

•Origin: inferior border of the rib above

•Insertion: superior border of the rib below

•Action: elevate ribs and expand thoracic cage

Internal Intercostals

•Origin: superior border of the rib below

•Insertion: inferior border of the rib above

•Action: pulls ribs toward one another

Serratus anterior

•Origin: anterior surface of upper ribs

•Insertion: medial border of scapula

Action:

•Protracts and rotates the scapula laterally

Punching motion

Rectus abdominus

•Origin: crest of the pubis/pubic symphysis

•Insertion: xiphoid process of the sternum and ribs 5-7

Action:

•Flexes vertebral column

•Rotate lumbar region of vertebral column

Transversus abdominus

•Origin: costal cartilages lower ribs, lumbar vertebrae, iliac crest

•Insertion: crest of pubis, Linea alba

Action:

•Compresses abdomen

External Obliques

•Origin: outer surfaces of lower 8 ribs

•Insertion: linea alba, iliac crest

•Action: compresses abdomen, flexes and rotate vertebral column, lateral flexion

Internal Obliques

•Origin: iliac crest, lumbar fascia

•Insertion: linea alba, lower 3-4 ribs and crest of pubis

•Action: compresses abdomen, flexes and rotate vertebral column, lateral flexion