Orbicularis Oculi Muscle Anatomy

Orbicularis oculi

1. Scalp, Temple, and Face
   (Orbiculus—oit, oculi-eyeball)
2. Orbicularis Oculi Introduction: It is a muscle of the face, the sphincter of the orbital fissure.
3. Orbicularis Oculi Attachments: It has three parts:
4. Orbicularis Oculi Palpebral part: It is confined to the lids. It arises from the medial palpebral ligament.
5. Orbicularis Oculi is inserted into the lateral palpebral raphe.
6. Orbital part: It extends beyond orbit. It arises from
7. Nasal part of the frontal bone
8. Anterior lacrimal crest
9. Frontal process of the maxilla: It forms concentric rings and returns to the point of -origin.
10. Lacrimal part (deeper part): It is attached medially to the
11. Posterior lacrimal crest, and Lacrimal sac,
12. They are inserted into the upper and lower eyelids.

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Orbicularis Oculi Nerve supply

Mainly by a zygomatic branch of the facial nerve.
It is also supplied by the temporal branch of the facial nerve.

Orbicularis Oculi Actions
The palpebral part closes the eyelid gently.
Orbital and palpebral parts together closes the eyelid forcibly.
Levator palpebrae superioris is the opponent of upper palpebral fibres of orbicularis oculi.
Occipitofrontalis opposes the orbital part.

Orbicularis Oculi Development: They are developed from the mesoderm of the 2nd pharyngeal arch.

Orbicularis Oculi Applied anatomy : Infranuclear lesion of the facial nerve leads to paralysis of orbicularis oculi.

Hence, the patient cannot close the eyelid tightly.

Frequent closure of eyelids is required for the normal drainage of tears through the lacrimal ducts.

Due to paralysis of orbicularis oculi, there is overflowing of tears through the eyelid and expose keratitis.

Enumerate the branches of facial artery on the face
1. Inferior labial,
2. Superior labial,
3. Lateral nasal, and
4. Angular artery.

Describe facial nerve under the following headings:
1. Course and relations
2. Branches
3. Applied anatomy
It is a nerve of 2nd pharyngeal arch.

1. Orbicularis Oculi Course and relations

Intraneuronal Motor root arises from motor nuclei of facial nerve situated in deep part of pons.

Orbicularis Oculi winds around abducent nucleus. It forms a bulging in the floor of IVth ventricle called facial colliculus.

Orbicularis Oculi is due to the phenomenon of neurobiotaxis.

The nerve fibres have a tendency to migrate in the direction from which they receive their stimuli.

• Sensory root (nervus intermedius) is formed by
• Superior salivatory nucleus and lacrimatory nucleus.
• Nucleus tractus solitarius.
• Both the roots emerge at the junction of pons and olive.

Orbicularis Oculi Extraneuronal: Divided into three parts

Orbicularis Oculi First part: Orbicularis Oculi First part passes through the internal acoustic meatus.
Orbicularis Oculi First part reaches anterosuperior angle of the medial wall of the middle ear cavity. It bends to form second part.
Orbicularis Oculi First part  forms a bulging at the bend called geniculate ganglion.

Orbicularis Oculi Second part: Orbicularis Oculi Second part  runs horizontally backwards along medial wall of tympanic cavity.
Orbicularis Oculi Second part lies above promontory and fenestra vetibuli and runs to the posterior part of medial wall.

Orbicularis Oculi Third part: Orbicularis Oculi Third part is posterior to posterior wall of middle ear cavity.
Runs vertically downwards and comes outside the cranium through stylomastoid foramen.

Orbicularis Oculi Extracranial: It turns anteriorly and pierces the posteromedial surface of parotid gland.
It emerges from anteromedial surface of parotid gland.
Terminates in the parotid gland: By dividing into terminal branches.
Branches
Intracranial

First part: No branches:
At the junction of 1st and 2nd parts, greater petrosal nerve arises.
It carries secretomotor fibres to the lacrimal gland.

Second part:
Sympathetic branches to middle meningeal artery.

Branch to lesser petrosal nerve, by which it reaches the otic ganglion.

Third part:

Stapedial branch: It passes through small canal and supplies stapedius muscle.

Chordatymni nerve: Itjoins ligul nerve and carries tate fires frmanteior 2/3rd oftongu.

Italsocarries secretomotor fires tosubmandibulargland .

Communicating branch to vagus.

Extracranial

1. Posterior auricular branch gives communicating branch to great auricular and lesser occipital. It divides into
2. Auricular branch to auricularis posterior.
3. Occipital branch to occipital belly of occipitofrontalis.
4. Digastric branch to posterior belly of digastric.
5. Stylohyoid branch to stylohyoid muscle.
6. Terminal
7. Temporal branch to
8. Frontal belly of occipitofrontalis,
9. Muscles of external ear
10. Auricularis superior
11. Auricularis anterior
12. Corrugator supercilii.
13. Zygomatic branch to orbicularis oculi
14. Buccal
15. Upper (lower zygomatic)
16. Zygomaticus major
17. Zygomaticus minor
18. Levator labii superioris
19. Levator labii superioris alaequae nasi
20. Levator anguli oris
21. Lower
22. Buccinator
23. Orbicularis oris
24. Mandibular branch to risorius.
25. Cervical branch to platysma

Pes anserinus (pes-foot, anser-goose)NEET: Branches of the facial nerve in the substance of parotid gland form a network called pes anserinus.

This divides the parotid gland into superficial and deep parts.

Pes anserinus
1.Branches of facial nerve
2.Muscles attached to upper part of medial surface of tibia.
3. Applied anatomy Upper and lower motor neuron lesion of facial nerve.

Note: While attempting to close the right eye (paralyzed side), the eye does not close and the eyeball rotates superiorly and laterally