OIAI of Muscles

Origin of Platysma

Mid-dorsal tendinous raphe of the skin and neck

Insertion of Platysma

Covers the parotid and masseter region of the cheek and lips

Action of Platysma

Draws the commissure of the lips caudally

Innervation of Platysma

Facial Nerve (Dorsal and ventral branch of the buccal and branch of posterior auricular nerve)

Origin of Orbicularis Oris

Commissure of the lips

Insertion of Orbicularis oris

Skin and Mucosa

Action of Orbicularis oris

To close the mouth and to draw the nose downward (sniffing).

Innervation of Orbicularis oris

Facial Nerve (Dorsal and ventral branches of the buccal region)

Origin of Incisivus Superioris et Inferioris

Lies deep the orbicularis oris

Insertion of Incisivus Superioris et Inferioris

Alveolar border of the incisive bone and the mandible

Action of Incisivus Superioris et Inferioris

Extend and dilate the external nares

Innervation of Incisivus Superioris et Inferioris

Facial Nerve

Origin of Maxillonasolabial

Levator labii superioris or maxillaris - beneath the apical region of levator nasolabialis

Origin of Caninus

Extend over the labial and of the levator nasolabialis to the upper lip

Insertion of Maxillonasolabial and Caninus

Nasal ala and upper lip

Action of Maxillonasolabial and Caninus

Increase the diameter of the external nares and lift the apical portion of the upper lip

Innervation of Maxillonasolabial and Caninus

Facial Nerve

Origin of Pars buccalis

Upper lip

Origin of pars molaris

Lower lip

Insertion of pars buccalis

Alveolar border of the maxilla

Insertion of the pars molaris

Alveolar border of the mandible

Action of buccinators

To return the food from the vestibule to the masticatory surface of the tooth

Innervation of buccinators

Facial nerve

Origin of Mentalis

Alveolar border and body of mandible

Insertion of Mentalis

Lower lip

Action of Mentalis

To stiffen the lower lip in the apical region

Innervation of Mentalis

Facial Nerve

Origin of Zygomaticus

Rostral angle of the scutulum to the edge of the mouth

Insertion of Zygomaticus

Palpebral portion of the sphincter colli profundus

Action of Zygomaticus

Fix the angle of the mouth and draws it back

Innervation of Zygomaticus

Facial Nerve (Ramus auriculopalpebralis)

Origin of Frontalis

Lies on the temporal

Insertion of Frontalis

Rostral border of the scutulum beneath the sphincter colli profundus

Action of Frontalis

Fix and pull the scutulum forward

Innervation of Frontalis

Facial Nerve (Rami temporalis and auriculopalpebralis nerve)

Origin of Orbicularis Oculi

Palpebral fissure

Insertion of Orbicularis Oculi

Medial palpebral ligament of the upper lid

Action of Orbicularis Oculi

Closes the palpebral fissure

Innervation of Orbicularis Oculi

Facial Nerve (Ramus auriculopalpebralis)

Origin of Levator palpebrae superioris

Arise dorsal to optic canal, between dorsal rectus and dorsal obliquus

Insertion of Levator palpebrae superioris

Periorbita and upper lid

Action of Levator palpebrae superioris

Lifts the upper lid

Innervation of Levator palpebrae superioris

Oculomotor Nerve

Origin of Retractor Anguli Oculi Lateralis

Temporal fascia

Insertion of Retractor Anguli Oculi Lateralis

Lateral palpebral angle and crosses the orbicularis oculi

Action of Retractor Anguli Oculi Lateralis

To draw the lateral palpebral angle caudally

Innervation of Retractor Anguli Oculi Lateralis

Facial Nerve (Ramus auriculopalpebralis)

Origin of Levator anguli oculi medialis

Median line of frontal bone from nasofrontal fascia

Insertion of Levator anguli oculi medialis

Orbicularis oculi into half of upper eyelid

Action of Levator anguli oculi medialis

Lift the upper eyelid, erect the hair of eyebrow

Innervation of Levator anguli oculi medialis

Facial Nerve (Ramus auriculopalpebralis)

Origin of Levator nasolabialis

Beneath the skin of the lateral surface of the nasal and maxillary region

Insertion of Levator nasolabialis

Caudal portion of buccinator and apical portion of orbicularis oris and maxillonasolabialis

Action of Levator nasolabialis

Increase the diameter of the nose and lift the apical portion of the upper lid

Innervation of Levator nasolabialis

Facial Nerve (Ramus auriculopalpebralis)

Origin of Masseter

Lateral surface of the ramus of the mandible ventral to the zygomatic arch

Insertion of Masseter

Ventromedial and ventrolateral surface of mandible

action of Masseter

To raise the mandible in closing the mouth

Innervation of Masseter

Trigeminal Nerve

Origin of Temporalis

Temporal fossa

Insertion of Temporalis

Coronoid process of the mandible

Action of Temporalis

To raise the mandible in closing the mouth

Innervation of Temporalis

Trigeminal Nerve (N. temporalis of the ramus mandibular)

Origin of Pterygoideus lateralis

Sphenoid bone, ventral to alar canal, round foramen, and orbital fissure

Insertion of Pterygoideus lateralis

Medial surface of the mandibular condyle

Action of the Pterygoideus lateralis

To raise the mandible

Innervation of the Pterygoideus lateralis

Trigeminal nerve (N. Pterygoidei of the ramus mandibular)

Origin of Pterygoideus medialis

Lateral surface of the pterygoid, palatine, and sphenoid bone

Insertion of Pterygoideus medialis

Medial and caudal surface of the angular process of the mandible

Action of Pterygoideus medialis

To raise the mandible

Innervation of Pterygoideus medialis

Trigeminal Nerve

Origin of iliocostalis lumborum

Pelvic surface of the wing of the ilium and iliac crest

Insertion of iliocostalis lumborum

Runs towards the cranial end of 6th-13th rib

Action of the iliocostalis lumborum

Fixation of vertebral column; lateral movement only when one side contracts

Innervation of iliocostalis lumborum

Dorsal branch of thoracic and lumbar nerve

Origin of iliocostalis thoracis

Cranial part of the iliocostalis lumborum; longissimus up to the 3rd-5th rib

Insertion of iliocostalis thoracis

Extends up to the ribs except the first and last to the C7

Action of iliocostalis thoracis

Expiration by pulling the ribs caudally

Innervation of iliocostalis thoracis

Dorsal branch of thoracic and lumbar nerve

Origin of Longissimus Thoracis et Lumborum

Lateral to the spinous process of thoracic and lumbar vertebrae and dorsal to lumbar transverse process and ribs

Insertion of Longissimus Thoracis et Lumborum

Iliac crest to the last cervical vertebra

Action of Longissimus Thoracis et Lumborum

Extends vertebral column; raises the cranial portion of the body from the pelvis, sacrum, and loin

Innervation of Longissimus Thoracis et Lumborum

Dorsal branch of thoracic and lumbar nerve

Origin of Longissimus Lumborum

Iliac crest and ventral surface of ilium and medially from the spinous process and supraspinous ligament

Insertion of Longissimus Lumborum

Craniolateral part of ilium

Action of Longissimus Lumborum

Fixation of vertebral column

Innervation of Longissimus Lumborum

Dorsal branch of thoracic and lumbar nerve

Origin of Longissimus Thoracis

Runs caudal border of ribs

Insertion of Longissimus Thoracis

Craniolateral part of ilium

Action of Longissimus Thoracis

Extend the neck

Innervation of Longissimus Thoracis

Dorsal branch of the thoracic and lumbar nerve

Origin of Longissimus cervicis

Continuation of the longissimus thoracis, lying between the cervical and thoracic vertebrae

Insertion of Longissimus cervicis

Craniolateral part of ilium

Action of Longissimus cervicis

Extend the neck

Innervation of Longissimus cervicis

Dorsal branch of the thoracic and lumbar nerve

Origin of Longissimus capitis et atlantis

Lies medial to the longissimus cervicis and splenius

Insertion of Longissimus capitis et atlantis

Extend to the first three thoracic vertebrae to the temporal fossa

Action of Longissimus capitis et atlantis

Extends the atlanto-occipital joint, rotates the atlanto-axial joint, fixes the atlanto-axial joint

Innervation of Longissimus capitis et atlantis

Dorsal branch of cervical nerve

Origin of Intercostales Externi

Caudal border of each ribs