Skip to main content
Library homepage
 

Text Color

Text Size

 

Margin Size

 

Font Type

Enable Dyslexic Font
Biology LibreTexts

8.4: MODELS- Head and Neck and Torso

( \newcommand{\kernel}{\mathrm{null}\,}\)

 

Name

Action

Origin

Insertion

Muscles of facial expression

Frontalis (epicranius)

Raises eyebrows , wrinkles forehead

Frontal Bone

Skin of the brow

Occipitalis (epicranius)

Pull scalp posteriorly

Occipital bone

Aponeurosis connecting to frontalis

Orbicularis oris

Closes mouth

Maxillae and Mandible

Lips

Zygomaticus (major/minor)

smile 

Zygomatic Bone

mouth

Orbicularis oculi

Closes eye

Margin of Orbit

Eyelid

Masseter

Elevates mandible

Zygomatic Arch

Mandible

Temporalis

Elevates mandible

Temporal Bone

Mandible

Buccinator

Presses cheek inward

Maxillae and Mandible

orbicularis oris

Muscles of the head, vertebral column and abdominal wall

Splenius capitis

extend + laterally flex head

upper spine

Temporal & occipital

Sternocleidomastoid

Flexes + rotates neck (also elevates ribs)

Sternum & Clavicle

Mastoid Process

Scalenes

Flexes neck (also elevates ribs)

Cervical Vertebrae

1st Two Ribs

Rectus abdominus

Flexes vertebral column , compresses abdomen

Pubis

Lower Ribs and Xiphoid

External oblique

Flexes + rotates vertebral column,

compresses abdomen

Lower Ribs

Linea alba and Ilium

Internal oblique

Flexes + rotates vertebral column, compresses abdomen

Lumbar Vertebrae & Ilium

Lower Ribs, Linea alba, Sternum

Transverse abdominus

Compresses abdomen

Lower Ribs, Ilium, Lumbar

Vertebrae

Linea Alba & Pubis

Erector spinae group

Extends vertebral column

Ilium, Sacrum, Ribs, Vertebrae

Ribs, Vertebrae, Base of Skull

Levator scapulae

Extends neck (also elevates scapula)

Cervical Vertebrae

Scapula

Name

Action

Origin

Insertion

Thoracic & shoulder muscles

Pectoralis major

Flexes, adducts + medially rotates arm at shoulder

Sternum & Clavicle

Humerus

Pectoralis minor

Elevates ribs (also moves scapula anterior and inferior)

Ribs

Scapula

External intercostals

Elevates ribs

Inferior Rib

Superior rib

Internal intercostals

Depresses ribs

Superior rib

Inferior Rib

Diaphragm

Increases thoracic volume

Xiphoid Process, Ribs, Lumbar Vertebrae

Central Tendinous Sheet

Arm movers

Serratus anterior

Moves and fixes scapula anteriorly

Ribs

Scapula

Trapezius

Elevates, retracts, depresses+ rotates scapula upward (also extends neck)

Occipital Bone & Thoracic Vertebrae

Scapula

Rhomboids (major & minor)

Elevates + adducts scapula

Cervical & Thoracic

Vertebrae

Scapula

Latissimus dorsi

Extends, adducts + medially rotates arm at shoulder

Thoracic, Lumbar Vertebrae, Ribs

Humerus

Deltoid

Abducts arm at shoulder (also anterior fibers flex + posterior fibers extend arm at shoulder)

Clavicle & Scapula

Humerus

Teres major

Medially rotate arm

Scapula

Humerus

Rotator cuff (SITS)

Infraspinatus

Laterally rotates shoulder

Scapula

Humerus

Supraspinatus

Abducts shoulder

Scapula

Humerus

Subscapularis

Medially rotates shoulder

Scapula

Humerus

Teres minor

Laterally rotates shoulder

Scapula

Humerus


This page titled 8.4: MODELS- Head and Neck and Torso is shared under a CC BY-SA license and was authored, remixed, and/or curated by Laird C. Sheldahl.

Support Center

How can we help?