Ax: Muscle Origins and Insertions

Buccinator

Origin: Maxilla and Mandible

Insertion: orbicularis oris muscle

action: cheek compression

Depressor labii inferioris

Origin: mandible

Insertion: Skin, lower lip

Action: Lower lip (labii) depression

Levator labii superioris alaeque nasi

Origin: Maxilla

Insertion: Skin of upper lip, nostrils

Action: Flaring of nostrils, elevates upper lip

Mentalis

Origin: Mandible

Insertion: Skin of chin

Action: Lower lip elevation

Orbicularis Oris

Origin: Maxilla and Mandible

Insertion: Lips

Action: Lip puckering

Risorius

Origin: Parotid gland fascia

Insertion: skin of angle of the mouth

Action: corner of the mouth drawn to sides

Depressor anguli oris

Origin: mandible

Insertion: skin, angle of mouth

Action: corner or mouth depression, frown

Zygomaticus major

Origin: Zygomatic bons

Insertion: skin angle of mouth

Action: smile

Zygomaticus minor

Origin: zygomatic bone

Insertion: upper lip

Action: smile

Levator labii superioris

Origin: maxilla

Insertion: orcicularis oris muscle

Action: upper lip elevation

Orbicularis oculi

Origin: maxilla

Insertion: skin of orbits

Action: close eye

Levator palpebrae superioris

Origin: sphenoid

Insertion: upper eyelid

Action: eyelid elevation

Procerus Nasalis

Origin: Nasal cartilages and bones

Insertion: skin of forehead

Action: skin between eyebrows pulled downward-expression of frown

Occipitofrontalis, frontal belly

Origin: epicranial aponeurosis

Insertion: skin of eyebrows

Action: eyebrow elevation

Occipitofrontalis, occipital belly

Origin: occipital bone

Insertion: epicranial aponeurosis

Action: scalp moves posteriorly

Platysma

Origin: fascia overlying pectoralis major and deltoid muscles 

Insertion: Mandible

Action: Mandible depression (opens mouth)

Inferior Rectus

Origin: sphenoid

Insertion: inferior eyeball

Action: eye rotation downward and medially

Medial rectus

Origin: sphenoid

Insertion: medial eyeball

Action: eye rotates medially

superior rectus

Origin: sphenoid

Insertion: superior eyeball

Action: eye rotates upward

lateral rectus

Origin: sphenoid

Insertion: lateral eyeball

Action: eye rotates laterally

inferior oblique

Origin: maxilla

Insertion: inferior eyeball

Action: eye rotates upward and laterally

superior oblique

Origin: sphenoid

Insertion: superior eyeball

Action: eye rotates downward and laterally

massester

Origin: zygomatic bone

Insertion: mandible

Action: mandible elevation, chewing (closes mouth)

medial pterygoid

Origin: sphenoid, pterygoid process

Insertion: mandible

Action: mandible lateral movement (chewing)

temporalis

Origin: temporal

Insertion: mandible

Action: mandible elevation, chewing (closes mouth)

lateral pterygoid

Origin: Sphenoid, pterygoid process

Insertion: mandible

Action: mandible lateral movement (chewing)

digastric

Origin: mandible

Insertion: hyoid

Action: mandible depression (opens mouth)

Geniohyoid

Origin: mandible

Insertion: hyoid

Action: mandible depression (opens mouth)

Mylohyoid

Origin: mandible

Insertion: hyoid

Action: floor of mouth elevation

Omohyoid

Origin: scapula

Insertion: hyoid

Action: hyoid bone depression (aids in swallowing)

Sternohyoid

Origin: sternum and clavicle

Insertion: hyoid

Action: hyoid bone depression (aids in swallowing)

Sternothyroid

Origin: sternum

Insertion: thyroid cartilage

Action: hyoid bone depression (aids in swallowing)

Thyrohyoid

Origin: thyroid cartilage 

Insertion: hyoid 

Action: hyoid bone depression (aids in swallowing)

Sternocleidomastoid

Origin: sternum and clavicle

Insertion: mastoid process

Action: neck flexion

Stylohyoid

Origin: styloid process of temporal bone

Insertion: hyoid

Action: elevated hyoid

Splenius Capitis (superficial layer)

Origin: C and T vertebrae

Insertion: occipital bone

Action: neck extension

Erector spine (intermediate layer)

Origin: T and L vertebrae

Insertion: ribs/vertebrae

Action: vertebral column extension

Deep layer of intrinsic vertebral muscle

Origin: vertebrae

Insertion: vertebrae

Action: fine movements and stabilization of vertebral column

Scaleness

Origin: vertebrae

Insertion: ribs

Action: neck flexion

External intercostals

Origin: ribs

Insertion: ribs

Action: rib elevation

Internal intercostals

Origin: ribs

Insertion: ribs

Action: rib depression

External oblique

Origin: ribs

Insertion: linea alba

Action: compress abdomen

Internal oblique

Origin: ilium

Insertion: linea alba

Action: vertebral column rotation, compresses abdomen

Transversus abdominis

Origin: ribs and iliac crest

Insertion: linea alba

Action: compress abdomen

Rectus abdominis

Origin: pubis

Insertion: sternum

Action: compress abdomen (rib depression)

Diaphragm

Origin: ribs

Insertion: central tendon of the diaphragm

Action: contraction expands thoracic cavity (breathing)

Bulbospongiosus

Origin: perineal body

Insertion: perineal membrane and clitoris/penis

Action: stabilizes the perineal body, gland secretion, erection

Ischiocavernosus

Origin: ischium

Insertion: crus of clitoris/penis

Action: erection

Coccygeus

Origin: ischial spine

Insertion: sacrum and coccyx

Action: structural support

Iliococcygeus

Origin: ischium

Insertion: coccyx

Action: elevates pelvic floor

Pubococcygeus

Origin: pubis

Insertion: coccyx

Action: structural support, urinary and fecal continence

External anal sphincter

Origin: anococcygeal ligament, coccyx

Insertion: perineal body

Action: constricts anus

Superficial transverse perineal muscle

Origin: ischium

Insertion: perineal body

Action: structural support