Muscle | Origin | Insertion | Action |
- Frontal belly | | | |
- Posterior belly Galae aponeurotica (anteriorly) Occipital and temporal bones (posteriorly) Skin of eyebrows and root of nose (anteriorly) | | | |
Galae aponeurotica | | | |
(posteriorly) Elevates eyebrow, wrinkles forehead skin horizontally (frontalis); | | | |
Fixes galae aponeurotica and pulls scalp posteriorly (occipitalis) | | | |
Orbicularis oculi | | | |
| | | |
Frontal and maxillary bones Tissue of eyelid Closes eye, draws eyebrows inferiorly | | | |
Orbicularis oris | | | |
| | | |
O. oris o. oris Constricts and protrudes lips | | | |
Levator labii superioris | | | |
Maxilla, zygomatic o. oris Elevate lip | | | |
Depressor labii inferioris | | | |
Mandible o. oris Depress lip | | | |
Depressor anguli oris | | | |
Mandible o. oris Depress corners of the mouth | | | |
Levator anguli oris | | | |
Maxilla o. oris Raise mouth corners | | | |
*Buccinator | | | |
Maxilla, mandible o. oris Tense cheek | | | |
Risorius | | | |
Masseter o. oris Pulls corners of the mouth back – grimace | | | |
Zygomaticus | | | |
Zygomatic bone o. oris Raise corners of the mouth “smiling muscle” | | | |
*Note: This muscle is involved in both facial expression and mastication! | | | |
| | | |
Muscles of mastication | | | |
Origin Insertion Action | | | |
Masseter | | | |
| | | |
Zygomatic, temporal | | | |
(zygomatic arch) Mandible Chewing (jaw closure) | | | |
Temporalis | | | |
| | | |
Temporal Coronoid process of the Mandible Chewing (jaw closure) | | | |
Pterygoids (lateral and medial) | | | |
Sphenoid, palatine, maxilla Mandible Chewing (closure, protrusion, and side to side motion of mandible) | | | |
*Buccinator | | | |
Maxilla, mandible o. oris Tense cheek | | | |
Muscles of the neck | | | |
Origin Insertion Action | | | |
Platysma | | | |
| | | |
Fascia of chest muscles Mandible Tense skin of the neck | | | |
Sternocleidomastoid | | | |
Sternum and Clavicle Mastoid process Flexes and laterally rotates the head | | | |
Scalenes | | | |
Transverse processes of cervical vertebrae Ribs 1 and 2 Elevates first two ribs; flex and rotates neck | | | |
Splenius Capitus Ligamentum nuchae, spinous process of cervical vertebrea Mastoid process and occipital bone Extend or hyperextend head | | | |
Semispinalis capitis | | | |
Cervical and thoracic vertebrae Occipital bone Extends skull | | | |
Mylohyoid | | | |
Mandible Hyoid bone Elevates hyoid & floor of the mouth | | | |
Omohyoid | | | |
Scapula Hyoid bone Depress and retracts hyoid | | | |
Stylohyoid | | | |
Styloid process of the temporal bone Hyoid bone Elevate and retracts hyoid | | | |
Digastric | | | |
Mandible, mastoid process of the temporalbone Hyoid bone Open mouth and depress mandible, steady hyoid during swallowing | | | |
| | | |
Muscles of the Spine (page 338 text) | | | |
Erector spinae Origin Insertion Action | | | |
Iliocostalis Iliac crest; ribs Ribs; Transverse processes of cervical vertebrae Extend and laterally flex spine | | | |
Longissimus | Transverse processes of Lumbar & thoracic vertebrae Transverse processes of Thoracic & cervical vertebrae; ribs; skull mastoid process | | |
Spinalis | Spinous processes of Lumbar & thoracic vertebrae Spinous processes Thoracic & cervical vertebrae | | |
Epicranius | | | |