Muscles Promoting Facial Expressions epicranial aponeurosis (tendinous sheet) Frontalis (Epicranius) raises eyebrows; wrinkles forehead skin of eyebrows; root of nose occipital bone; temporal bone epicranial aponeurosis (tendinous sheet) Occipitalis (Epicranius) pulls scalp posteriorly frontal / maxillary bone; ligaments around orbit tissue of eyelid Orbicularis oculi closes eye zygomatic bone skin at corner of mouth Zygomaticus (major / minor) raises corner of mouth upwards ( smiling ) fascia of masseter muscle skin at corner of mouth Risorius draws corner of lips laterally 1
Levator labii superioris Depressor labii inferioris zygomatic bone; orbit of eye skin of upper lip opens lips body of mandible skin of lower lip draws lower lip inferiorly ( pout ) Depressor anguli oris Orbicularis oris body of mandible skin at corner of mouth draws corner of mouth downward ( frowning ) maxilla / mandible skin / muscles at angle of mouth closes lips; purses lips ( kissing / whistling ) Mentalis Buccinator mandible skin of chin wrinkles chin maxilla / mandible orbicularis oris muscle compress cheeks ( sucking ) 2
fascia of chest lower margin of mandible; skin at corner of mouth Platysma tenses skin of neck; depresses mandible Muscles Promoting Mastication & Tongue Movement Masseter Temporalis zygomatic arch / bone elevates mandible temporal bone elevates mandible angle / ramus of mandible coronoid process (mandible) Medial pterygoid Lateral pterygoid pterygoid process (sphenoid bone); maxilla protrudes jaw; promotes side-to-side chewing greater wing / pterygoid process (sphenoid bone) protrudes jaw; promotes side-to-side chewing body of mandible mandibular condyle (mandible) 3
Genioglossus Hyoglossus posterior body of mandible inferior aspect of tongue; body of protracts tongue ( sticking out tongue) body / greater horn of hyoid inferolateral tongue depresses tongue styloid process (temporal bone) Styloglossus retracts / elevates tongue Muscles Promoting Head Movement inferolateral tongue Muscles Promoting Head Movement Muscles Promoting Head Movement Sternocleidomastoid Scalenes medial portion of clavicle; manubrium (sternum) flexes / laterally rotates head of vertebrae C 2 C 6 flexes / laterally rotates neck; elevates ribs mastoid process (temporal bone); temporal bone anteriorlateral surface of first two ribs 4
Muscles Promoting Head Movement spinous processes of vertebrae C 7 T 6 Splenius (capitis/ cervicis) extends / laterally rotates head Muscles Promoting Swallowing / Speaking Transverse processes of vertebrae C 2 C 4 ; mastoid process (temporal bone) Digastric Stylohyoid lower margin of mandible; mastoid process (temporal bone) elevates / depresses mandible styloid process (temporal bone) elevates / retracts (connective tissue loop) Mylohyoid Geniohyoid medial inner surface of mandible elevates ; elevates floor of mouth medial inner surface of mandible elevates ; pulls anteriorly 5
Sternohyoid Sternothyroid manubrium (sternum); medial end of clavicle depresses posterior surface of manubrium (sternum) depresses ; depresses larynx lower margin of thyroid cartilage of larynx Omohyoid Thyrohyoid superior border of scapula lower margin of depresses / retracts thyroid cartilage of larynx depresses ; elevates larynx Muscles Promoting Trunk Extension Iliac crest (os coxa); ribs 3 12 Iliocostalis (Erector spinae) extends / laterally flexes vertebral column angles of ribs; of vertebrae C 4 C 6 6
of vertebrae C 1 L 5 of thoracic through cervical vertebrae; multiple ribs Longissimus (Erector spinae) extends / laterally flexes vertebral column spinous processes of upper lumbar and lower thoracic vertebrae spinous processes of upper thoracic and cervical vertebrae Spinalis (Erector spinae) extends vertebral column Semispinalis Quadratus lumborum of vertebrae C 7 T 12 extends vertebral column spinous processes of cervical and throacic vertebrae Iliac crest (os coxa) of vertebrae L 1 L 4 ; lower margin of rib 12 laterally flexes vertebral column Muscles Promoting Breathing Muscles Promoting Breathing inferior border of rib above External intercostals elevates rib cage superior border of rib below 7
Muscles Promoting Breathing Internal intercostals Muscles Promoting Breathing Diaphragm superior border of rib below inferior border of rib above depresses rib cage inferior internal surface of rib cage / sternum; lumbar vertebrae central tendon of diaphragm expands thoracic cavity Muscles Promoting Movement / Compression of Abdominal Wall Muscles Promoting Movement / Compression of Abdominal Wall pubic crest (os coxa) xiphoid process (sternum); ribs 5-7 Rectus abdominis flexes / rotates lumbar region of vertebral column Muscles Promoting Movement / Compression of Abdominal Wall External oblique Muscles Promoting Movement / Compression of Abdominal Wall Internal oblique outer surface of ribs 4 12 linea alba (tendinous sheet) flexes / rotates vertebral column; compresses abdominal wall iliac crest (os coxa) linea alba; pubic crest (os coxa); ribs 9 12 flexes / rotates vertebral column; compresses abdominal wall 8
Muscles Promoting Movement / Compression of Abdominal Wall lumbar vertebrae; ribs 7 12; iliac crest (os coxa) Transversus abdominis compress abdominal wall Muscles Promoting Pelvic Floor Support linea alba; pubic crest (os coxa) Muscles Promoting Pelvic Floor Support Muscles Promoting Pelvic Floor Support Levator ani Coccygeus inner pelvis from pubis to ischial spine inner surface of coccyx supports / maintains position of pelvic viscera ischial spine (ischium) sacrum; coccyx supports pelvic viscera (Medial view) (Medial view) 9