Muscular System

(muscles of facial expression)

• O: superior nuchal line of occipital bone and portion of mastoid process of temporal
• I: skin of eyebrow and root of nose
• N: VII-facial
• A: draws scalp back, raising the eyebrow and wrinkling the forehead (surprise)

(muscles of facial expression)

• O: orbital rim, frontal bone, and maxilla
• I: lateral canthus 
• N: VII-facial
• A: sphincter of the eyelids, thus closing the eye (squinting)

(muscles of facial expression)

• O: supraorbital region (frontal)
• I: skin of eyebrows
• N: VII-facial
• A: produces vertical wrinkles of the forehead (frowning)

(muscles of facial expression)

• O: encircles mouth
• I: labia commissure
• N: VII-facial
• A: although not a true sphincter, it produces sphincter-like action; closes and purses the lips (pouting)

-consist of muscle fibers blend at the angle: platysma, levator anguli oris, depressor anguli oris, zygomaticus major, and risorius

(muscles of facial expression) - blend with orbicularis oris

• O: maxilla (canine fossa) 
• I: labial commisure
• N: VII-facial 
• A: elevates the angle of the mouth (smiling)

(muscles of facial expression)- blend with orbicular oris

• O: mandible
• I: labial commissure
• N: VII-facial
• A: depresses the angle of the mouth (frowning)

(muscles of facial expression)- blend with orbicular oris

• O: zygomatic bone
• I: labial commissure
• N: VII-facial
• A: elevates the upper lip (smiling)

(muscles of facial expression)-blend with orbicular oris

• O: fascia superficial to masseter muscle
• I: labial commissure
• N: VII-facial
• A: widens the mouth as in smiling (stretching lips - grimacing)

(muscles of facial expression)

• O: maxilla
• I: upper lip
• N: VII-facial
• A: elevates/raising the upper lip

(muscles of facial expression)

• O: mandible
• I: lower lip
• N: VII-facial
• A: lowers/draws lower lip downwards and laterally

(muscles of facial expression)

• O: zygomatic bone
• I: upper lip
• N: VII-facial
• A: elevates the upper lip (smiling)

(muscles of facial expression)

• O: mandible
• I: chin
• N: VII-facial
• A: raises the skin of the chin and causes the lower lip to protrude

(muscles of facial expression)

• O: outer surface of alveolar of maxilla and mandible, and pterygomandibular raphe
• I: labial commissure
• N: VII-facial
• A: compresses cheek during chewing. Also acts in blowing and sucking

- local anesthetic landmark

(muscles of mastication)

• O: zygomatic arch
• I: angle and ramus of mandible
• N: V(3)-trigeminal
• A: elevates the mandible

-largest, strongest, and most superficial muscle

(muscles of mastication)

• O: temporal fossa of temporal bone
• I: coronoid process of mandible
• N: V(3)-trigeminal
• A: when whole muscle contracts it elevates the mandible, when posterior contracts it retrudes the mandible

(muscles of mastication)

• O: larger (deep) head - pterygoid fossa of medial surface; smaller (superficial) head - lateral surface of both pyramidal process of palatine bone and maxillary tuberosity
• I: both heads: medial surface of mandibular ramus and angle of mandible
• N: V(3)-trigeminal
• A: elevates mandible

(muscles of mastication)

• O: lateral surface of lateral pterygoid plate in sphenoid (in part - superior & inferior)
• I: anterior surface of neck on mandibular condyle at pterygoid fovea of mandible
• N: V(3)-trigeminal
• A: depresses and protrudes mandible. if one side contracts, it moves mandible to contralateral side. a portion of the lateral pterygoid inserts on the articular disc of the TMJ

(muscles of neck)

• O: clavicle and shoulder
• I: mandible and muscles of the mouth
• N: VII-facial
• A: draws lips downwards and raises the skin of the neck

(muscles of neck)

• O: medial part of the clavicle and sternum's superior and lateral surface
• I: mastoid process of temporal bone
• N: XI-accessory 
• A: if one muscle contracts it draws the head towards the shoulder on the same side such that the chin points upwards and to the opposite side. if both muscles contracts the neck is flexed

(muscles of neck)

• O: external surface of occipital bone at nuchal line
• I: lateral third of the clavicle and part of scapula 
• N: XI-accessory
• A: elevates the scapula and clavicle (shrugging the shoulder)

(hyoid muscles) - suprahyoid

• O: anterior - greater cornu of hyoid bone; posterior - mastoid notch
• I: anterior - digastric fossa of medial surface of mandible; posterior - intermediate tendon
• N: anterior - V; posterior - VII
• A: raises hyoid bone and assists in opening the mandible

(hyoid muscles) - suprahyoid

• O: mylohyoid line
• I: mylohyoid raphe
• N: V-trigeminal 
• A: elevates tongue

-forms floor of the mouth

(hyoid muscles) - suprahyoid

• O: styloid process of temporal bone
• I: body of hyoid
• N: VII-facial
• A: draws hyoid bone upward and backward

(hyoid muscles) - suprahyoid

• O: genial tubercles
• I: body of hyoid
• N: cervical nerve
• A: helps elevate and protrude tongue

(hyoid muscles) - infrahyoid

• O: posterior surface of sternum
• I: thyroid cartilage 
• A: depresses thyroid cartilage

(hyoid muscles) - infrahyoid

• O: posterior and superior surface of sternum
• I: body of hyoid
• A: depresses hyoid bone

(hyoid muscles) - infrahyoid

• O: inferior belly - scapula; superior belly - short tendon 
• I: inferior belly - internal jugular vein; superior belly - body of hyoid
• A: depresses hyoid bone

(hyoid muscles) - infrahyoid

• O: thyroid cartilage
• I: body and greater cornu of hyoid body
• A: raises thyroid cartilage and larynx

(muscles of the tongue) - intrinsic

• O: dorsal surface of tongue
• I: from base to apex of tongue
• N: XII-hypoglossal
• A: change shape of tongue (curl)

(muscles of the tongue) - intrinsic

• O: ventral surface of tongue
• I: from base to apex of tongue
• N: XII-hypoglossal 
• A: change shape of tongue (curl)

(muscles of the tongue) - intrinsic

• O: transverse direction 
• I: lateral surface
• N: XII-hypoglossal 
• A: change shape of tongue (curl)

(muscles of the tongue) - intrinsic

• O: vertical direction of dorsal
• I: to ventral surface in the body
• N: XII-hypoglossal 
• A: change shape of tongue (curl)

(muscles of the tongue) - extrinsic

• O: genial tibercles
• I: hyoid bone
• N: XII-hypoglossal 
• A: change shape of tongue

-safety muscle of the tongue

(muscles of the tongue) - extrinsic

• O: greater cornu & body of hyoid
• I: tongue
• N: XII-hypoglossal 
• A: change shape of tongue

(muscles of the tongue) - extrinsic

• O: styloid process of temporal
• I: tongue
• N: XII-hypoglossal 
• A: change shape of tongue

(muscles of the soft palate)

• O: soft palate
• I: laryngopharynx & thyroid cartilage
• N: X-vagus
• A: pulls pharynx/palate posteriorly almost pulling both sides together. the uvula fills the slight space between the two pillars. closes nasopharynx during swallowing

(muscles of the soft palate)

• O: median palatine raphe
• I: lateral surface of tongue
• N: X-vagus
• A: elevates the base of the tongue toward the soft palate while pulling the soft palate toward the tongue. constricts after the bolus of food passes during swallowing

(muscles of the soft palate)

• O: temporal bone
• I: median palatine raphe
• N: X-vagus
• A: helps raise the soft palate during swallowing

(muscles of the soft palate)

• O: uvula
• I: uvula
• N: X-vagus
• A: helps close pharynx during swallowing

(muscles of the soft palate)

• O: auditory tube & inferior surface of sphenoid bone
• I: becomes tendon near hamulus of medial pterygoid plate; tendon forms palatine aponeurosis & inserts at median palatine raphe
• N: V(3)-trigeminal
• A: tenses soft palate and opens auditory tube to assist in pressure equalization

(muscles of laryngeal pharynx)

• I: median pharyngeal raphe
• N: X-vagus & pharyngeal plexus XI-accessory
• A: make up inner layers

(muscles of laryngeal pharynx)

• I: median pharyngeal raphe
• N: X-vagus & pharyngeal plexus XI-accessory
• A: make up the outer layers