FINALS PT1: Anatomy of Facial, Eye, Neck, and Thoracic Muscles

PLATYSMA

Origin: Mid-dorsal tendinous raphe of the neck and skin;

Insertion: Covers the parotid and masseter region of the cheek and lips;

Action: To draw the commissure of the lips caudally; pull the lip corner backward

Innervation: Facial nerve, Dorsal and ventral branch of buccal, Branch of posterior auricular nerve.

ORBICULARIS ORIS

Origin: Commissure of the lips;

Insertion: Skin and mucosa;

Action: To close the mouth and pulls the nose downward (sniffing);

Innervation: Facial nerve, Dorsal and ventral branch of the buccal region.

INCISIVUS SUPERIORIS et INFERIORIS

Origin: Lies deep to the Orbicularis Oris;

Insertion: Alveolar border of the incisive bone and mandible;

Action: Extend and dilate the external nares; open and widen the nostrils

Innervation: Facial nerve.

MAXILLONASOLABIAL (Nasal Part)

Origin: Levator labii superioris or maxillaris beneath the apical (tip) end of L. nasolabialis;

Insertion: Nasal ala and upper lip;

Action: Increase the diameter of the external nares and lift the apical portion of the upper lip; widen the nostrils and raise the tip of the upper lip

Innervation: Facial nerve.

CANINUS (Labial Part)

Origin: Extend over the labial end of levator nasolabialis into the upper lip;

Insertion: Nasal ala and upper lip;

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

Innervation: Facial nerve.

BUCCINATOR (consists of two parts)

1. Pars buccalis (pars dorsalis): Origin: Upper lip; Insertion: Alveolar border of maxilla; Action: To return the food from the vestibule to the masticatory surface of the tooth; Innervation: Facial nerve.

2. Pars molaris (pars ventralis): Origin: Lower lip; Insertion: Alveolar border of mandible; Action: To return the food from the vestibule to the masticatory surface of the tooth; Innervation: Facial nerve.

MENTALIS

Origin: Alveolar border and body of the mandible;

Insertion: Lower lip;

Action: Stiffen the lower lip in the apical region; make the tip of the lower lip firm

Innervation: Facial nerve.

ZYGOMATICUS

Origin: Rostral angle of the scutulum to the edge of the mouth;

Insertion: Palpebral portion of sphincter colli profundus;

Action: Fix the angle of the mouth and draw it back;

Innervation: Facial nerve, Ramus auriculopalpebralis.

FRONTALIS

Origin: Lies on the temporal;

Insertion: Rostral border of the scutulum (small plate of cartilage at the base of the ear) beneath the sphincter colli profundus;

Action: Fix and pull the scutulum forward;

Innervation: Facial nerve, Rami temporalis and auriculopalpebralis nerve.

ORBICULARIS OCULI

Origin: Palpebral fissure; opening gap between the upper and lower

Iimbs

Insertion: Medial palpebral ligament of the upper lid;

Action: Close the palpebral fissure;

Innervation: Facial nerve, Ramus auriculopalpebralis.

LEVATOR PALPEBRAE SUPERIORIS

Origin: Arise dorsal to optic canal between the dorsal rectus and dorsal oblique;

Insertion: Periorbita and upper lid;

Action: To lift the upper lid;

Innervation: Oculomotor nerve.

RETRACTOR ANGULI OCULI LATERALIS

Origin: Temporal fascia;

Insertion: Lateral palpebral angle and crosses the orbicularis oculi;

Action: To draw the lateral palpebral angle caudally;

Innervation: Facial nerve, Ramus auriculopalpebralis.

LEVATOR ANGULI OCULI MEDIALIS

Origin: Median line of frontal bone from nasofrontal fascia;

Insertion: Orbicularis oculi into half of upper eyelid;

Action: Lift the upper lid, erect the hair of eyebrow;

Innervation: Facial nerve, Ramus auriculopalpebralis.

LEVATOR NASOLABIALIS

Origin: Beneath the skin of the lateral surface of nasal and maxillary region;

Insertion: Caudal portion of buccinator and apical portion of orbicularis oris and maxillonasolabialis;

Action: Increases the diameter of the nose and lifts the apical portion of the upper lid;

Innervation: Facial nerve, Ramus auriculopalpebralis.

OBLIQUUS VENTRALIS

Origin: Rostrolateral margin of the palatine bone, adjacent to the suture between the palatine, lacrimal and maxillary bone;

Insertion: Below the insertion of the ventral rectus;

Action: To rotate the eyeball;

Innervation: Oculomotor nerve.

OBLIQUUS DORSALIS OR TROCHLEARIS

Origin: Medial border of the optic canal;

Insertion: Dorso-medial face of the periorbita to the medial canthus of the eye; from the upper inner part of the eye socket to the inner corner of the eye

Action: To rotate the eyeball;

Innervation: Trochlear nerve.

RECTUS DORSALIS

Origin: Arises at the optic canal;

Insertion: Medial and lateral recti;

Action: Rotates the eyeball on the vertical axis;

Innervation: Oculomotor nerve.

RECTUS LATERALIS

Origin: Arises at the optic canal;

Insertion: Medial and lateral recti;

Action: Rotates the eyeball vertically;

Innervation: Abducens nerve.

RECTUS MEDIALIS

Origin: Arises at the optic canal;

Insertion: Medial and lateral recti;

Action: Rotates the eyeball on the vertical axis;

Innervation: Oculomotor nerve.

RECTUS VENTRALIS

Origin: Arises at the optic canal;

Insertion: Medial and lateral recti;

Action: Rotates the eyeball horizontally;

Innervation: Oculomotor nerve.

RETRACTOR BULBI

Origin: Arises deep on rectus muscles at the apex of the orbit;

Insertion: Equator of the eyeball;

Action: To retract the eyeball and aids in bringing oblique eye movement;

Innervation: Abducens nerve.

MASSETER

Origin: Lateral surface of the ramus of the mandible ventral to the zygomatic arch;

Insertion: Ventrolateral and ventromedial surface of the mandible;

Action: To raise the mandible in closing the mouth;

Innervation: Trigeminal nerve.

TEMPORALIS

Origin: Temporal fossa;

Insertion: Coronoid process of the mandible;

Action: To raise the mandible in closing the mouth;

Innervation: Trigeminal nerve.

PTERYGOIDEUS LATERALIS

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

Insertion: Medial surface of the mandibular condyle;

Action: To raise the mandible;

Innervation: Trigeminal nerve.

PTERYGOIDEUS MEDIALIS

Origin: Lateral surface of the pterygoid, palatine and sphenoid bones;

Insertion: Medial and caudal surface of the angular process of the mandible;

Action: To raise the mandible;

Innervation: Trigeminal nerve.

ILIOCOSTALIS LUMBORUM

Origin: Pelvic surface of the wing of the ilium and iliac crest;

Insertion: Runs towards the cranial end of the 6th-13th ribs;

Action: Fixation of the vertebral column; Lateral movement when only one side contracts;

Innervation: Dorsal branch of the THORACIC & LUMBAR NERVE.

ILIOCOSTALIS THORACIS

Origin: Cranial part of iliocostalis lumborum, longissimus up to 3rd-5th ribs;

Insertion: Extends up to the ribs except the 1st and last to the transverse process of C7 vertebra;

Action: Expiration by pulling the ribs caudally;

Innervation: Dorsal branch of the THORACIC & LUMBAR NERVE.

LONGISSIMUS THORACIS et LUMBORUM

Origin: Lateral to the spinous process to the lumbar and thoracic vertebrae; Dorsal to the lumbar transverse process and ribs.

Insertion: Iliac crest to the last cervical vertebrae.

Action: Extend the vertebral column; Raises the cranial portion of the body from the pelvis, sacrum and loin.

Innervation: Dorsal branch of the THORACIC & LUMBAR NERVE.

LONGISSIMUS LUMBORUM

Origin: Iliac crest and ventral surface of ilium; Medially from the spinous process and supraspinous ligament.

Insertion: Craniolateral part of the ilium.

Action: Fixation of the vertebral column (cervicothoracic junction).

Innervation: Dorsal branch of the THORACIC & LUMBAR NERVE.

LONGISSIMUS THORACIS

Origin: Runs along the caudal border of the ribs.

Insertion: Craniolateral part of the ilium.

Action: Extend the neck.

Innervation: Dorsal branch of the THORACIC & LUMBAR NERVE.

LONGISSIMUS CERVICIS

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

Insertion: Craniolateral part of the ilium.

Action: Extend the neck.

Innervation: Dorsal branch of the THORACIC & LUMBAR NERVE.

LONGISSIMUS CAPITIS et ATLANTIS

Origin: Lies medial to the longus cervicis and splenius.

Insertion: Extends to the first 3 thoracic vertebrae to the temporal fossa.

Action: Extension of the atlanto-occipital joint; Rotates the atlantoaxial joint; Fixes the atlantoaxial joint.

Innervation: Dorsal branch of the CERVICAL NERVE.

COMPLEXUS

Origin: Caudal auricular process of Cervical 3rd to Thoracic 1st, with the Longissimus capitis.

Insertion: Craniomedially on the dorsal nuchal line.

Action: To raise the head and neck; To flex the head and neck.

Innervation: Dorsal branch of the CERVICAL NERVE.

SPINALIS et SEMISPINALIS THORACIS

Origin: Fascie of longissimus from the spinous process of Thoracic 7th-11th.

Insertion: Spinous process of Cervical 6 to Thoracic 6.

Action: Fix the thoracic vertebrae; Raise the neck.

Innervation: Dorsal branch of the CERVICAL & THORACIC NERVE.

SPINALIS CERVICIS

Origin: Tendon of the thoracic segment of the Semispinalis thoracis.

Insertion: Spinous process of Cervical 2-5, partly covered by Multifidus.

Action: Fix the thoracic vertebrae; Raise the neck.

Innervation: Dorsal branch of the CERVICAL & THORACIC NERVE.

MULTIFIDUS CERVICIS

Origin: Covered by semispinalis cervicis.

Insertion: Extend to articular process of the Thoracic 2 up to the axis.

Action: Fixes the vertebral column; Bilateral action of the back.

Innervation: Medial borders of the rami dorsalis of the CERVICAL, THORACIC & LUMBAR NERVE.

MULTIFIDUS LUMBORUM

Origin: From the sacrum to the spinous process of Thoracic 8-9.

Insertion: Extend to articular process of the Thoracic 2 up to the axis.

Action: Fixes the vertebral column; Bilateral action of the back.

Innervation: Medial borders of the rami dorsalis of the CERVICAL, THORACIC & LUMBAR NERVE.

MULTIFIDUS THORACIS

Origin: Mammillary process and transverse process of Thoracic 3-11 and spinous process of Thoracic 7-8.

Insertion: Extend to articular process of the Thoracic 2 up to the axis.

Action: Fixes the vertebral column; Bilateral action of the back.

Innervation: Medial borders of the rami dorsalis of the CERVICAL, THORACIC & LUMBAR NERVE.

RECTUS CAPITIS DORSALIS MAJOR

Origin: Covered by Semispinalis capitis, arising in ligamentum nuchae and caudal spine of the axis.

Insertion: Spine of the axis and squamous part of the occipital bone.

Action: Extend the atlanto-occipital joint.

Innervation: Dorsal branch of the CERVICAL NERVE.

RECTUS CAPITIS DORSALIS INTERMEDIUS

Origin: Cranial to the axis and atlas to the occipital bone.

Insertion: Ventral nuchal line.

Action: Extend the atlanto-occipital joint.

Innervation: Dorsal branch of the CERVICAL NERVE.

RECTUS CAPITIS DORSALIS MINOR

Origin: Between the atlas and occipital joint, arises to the cranial edge of the dorsal arch of the atlas.

Insertion: Foramen magnum near the ventral nuchal line.

Action: Extend the atlanto-occipital joint.

Innervation: Dorsal branch of the CERVICAL NERVE.

OBLIQUUS CAPITIS CAUDALIS

Origin: Entire spinous process of axis up to atlanto-occipital joint.

Insertion: Wing of the atlas near the alar notch.

Action: Rotation of the atlas and fixation of the atlantoaxial joint.

Innervation: Dorsal branch of the CERVICAL nerve I and II.

OBLIQUUS CAPITIS CRANIALIS

Origin: Lateroventral surface and lateral border of the wing of atlas.

Insertion: Between the Rectus capitis dorsalis major and dorsal nuchal line.

Action: Extension of the atlanto-occipital joint.

Innervation: Dorsalis branch of the CERVICAL NERVE I.

STERNOTHYROIDEUS

Origin: 1st costal cartilage covered by the sternocephalicus.

Insertion: Lateral surface of the thyroid lamina.

Action: To draw the hyoid apparatus, larynx and tongue.

Innervation: Ventral branch of CERVICAL NERVE I.

SCALENUS (DEEP)

Origin: S. primae costae; Cranial border of the 1st rib.

Insertion: Transverse process of Cerv. 5-6.

Action: To draw the neck downward; To bend the neck sideward; Inspiration. Innervation: Ventral part of the CERVICAL & THORACIC NERVE.

SCALENUS (SUPERFICIAL)

Origin: S. supra costalis; Outer surface of the ribs.

Insertion: Cervical vertebra.

Action: To draw the neck downward; To bend the neck sideward; Inspiration.

Innervation: Ventral part of the CERVICAL & THORACIC NERVE.

LONGUS CAPITIS & COLLI

Origin: Lateral and ventral side of cervical vertebra; Lies on its fellow on the bodies of the Thoracic 1-6 and all the cervical vertebrae.

Insertion: Muscular tubercle of basioccipital between the tympanic bulla.

Action: Fix the atlantooccipital joint; Draw the neck downward.

Innervation: Ventral part of CERVICAL NERVE.

RECTUS CAPITIS LATERALIS

Origin: Ventral surface of the wing of atlas.

Insertion: Base of the jugular process of the occipital bone.

Action: Fix the atlantooccipital joint.

Innervation: Ventral part of CERVICAL NERVE I.

INTERCOSTALES EXTERNI

Origin: Caudal border of each ribs.

Insertion: Caudoventrally to cranial border of next ribs.

Action: Inspiration.

Innervation: Muscular branch of INTERCOSTALES NERVE 1-12.

INTERCARTILAGINEI EXTERNI & INTERNI

Origin: Continuation of the intercostales externi into the interchondrial spaces.

Insertion: Interchondrial spaces.

Action: Inspiration.

Innervation: Muscular branch of INTERCOSTALES NERVE 1-12.

LEVATORES COSTARUM

Origin: Transverse process of the Thoracic 1-12.

Insertion: Cranial border of ribs 2nd to 10th.

Action: Inspiration.

Innervation: Muscular branch of INTERCOSTALES NERVE 1-12.

INTERCOSTALES INTERNI

Origin: Internal intercostal space and extend from the vertebral column to the distal end of the ribs.

Insertion: Cranial border of one rib to the caudal border of the next rib.

Action: Draw the ribs together.

Innervation: Muscular branch of INTERCOSTALES NERVE 1-12.

RECTUS THORACIS

Origin: Caudoventral to the 1st rib.

Insertion: Ventral end of the 2nd, 3rd & 4th ribs.

Action: Expiration.

Innervation: Lateral branch of INTERCOSTALES NERVE.

TRANSVERSUS THORACIS

Origin: Inner surface of the sternum and sternal costal cartilage.

Insertion: Aponeurosis of the lateral internal surface of the sternum from the 2nd sternebrae to xiphoid process.

Action: Expiration.

Innervation: Lateral branch of INTERCOSTALES NERVE.

RETRACTOR COSTAE

Origin: Lying on the origin of the transversus abdominis.

Insertion: Transverse abdominal m.

Action: Expiration.

Innervation: Lateral branch of INTERCOSTALES NERVE.