A6 - Facial and tongue muscles Flashcards
What is the action of the obicularis oculi?
Closes eyelids - outer orbital part closes them forcefully and the inner palpebral part closes them gently
(round eyes)
What is the action of levator labii superioris alaeque nasi?
Raises upper lip, opens nostrils
(strap like muscle going down side of nose)
What is the action of the nasalis?
Transverse part (over nose) - compresses nasal aperture
Alar part (under nostrils) - draws cartilage down and opens nostrils laterally
(main nose muscle)
What is the action of levator anguli oris?
Elevates the corner of mouth, deepens nasolibial furrow
(extends up from corner of mouth/ top lip into cheek)
What is the action of the buccinator?
Presses cheeks against teeth, prevents food accumulating here
(deep and main muscle in the cheek)
What is the action of risorious?
Pulls corner of mouth laterally and upwards
(strap muscle from corner of mouth to cheekbone)
What is the action of obicularis oris?
Closes and portrudes lips (purses)
(ring like muscle around the mouth)
What is the action of mentalis?
Raises and portrudes lower lip
(from lower lip to chin)
What is the action of platysma?
Tenses the skin
(muscle from lower mandible to neck)
What is the action of depressor labi inferioris?
Draws lower lip down and laterally
(extends down from middle of lower lip to either side of chin)
What is the action of depressor anguli oris?
Draws corner of mouth down and laterally
(extends down to chin from corner of mouth)
What is the action of depressor nasal septi?
Pulls nose inferiorly
(found right under nostrils)
What is the action of zygomaticus minor and major?
Draw corner of mouth up and laterally, and draws upper lip upwards
(strap like muscles from corner of mouth to in front of ear; minor is superior to major)
What is the action of levator labi superioris?
raises upper lip, forms nasolibial furrow
(from obicularis oris ring to where obicularis oculi ring is, sort of diagnoally)
What is the action of frontalis?
Moves the scalp, wrinkles the forehead
(forehead muscle)
What is the action of procerus?
Draws eyebrows down
(muscle right in middle of your eyebrows, goes onto nose)
What is the action of corrugator supercilli?
Draws eyebrows in and down
(small muscle medial to eyebrows and deep to obicularis oculi)
What muscle might be contracted when making a face of sadness?
Depressor anguli oris - corner of mouth down
Levator labi superioris - deepens furrow
Levator anguli oris - deepens furrow
Depressor labi inferioris - lower lip down and laterally
Mentalis - protrudes lower lip
What muscle might be contracted when making a face of disgust?
Levator labi superioris alaeque nasi - raises upper lip and opens nostrils
What muscle might be contracted when grinning?
Risorius - corner of mouth up and out
Depressor labi inferioris - pulls lower lip down to show teeth
What muscle might be contracted when angry?
Procerus - draws eyebrows down
Corrugator supercili - draws eyebrows down
Depressor anguli oris - corner of mouth down
Name the muscles of mastication
Temporalis
Masseter
Lateral pterygoid
Medial pterygoid
Which muscle of mastication may aid with depression of the mandible?
Lateral pterygoid - inferior head
For temporalis muscle, give its:
Origin
Insertion
Action
O: temporal fossa (temporalis line)
I: coronoid process of mandible
A: elevates and retracts mandible
For masseter muscle, give its:
Origin
Insertion
Action
O: Zygomatic arch
I: mandible (ramus, angle, lateral surface)
A: superficial part elevates the mandible, deep part retracts mandible
For lateral pterygoid muscle, give its:
Origin
Insertion
Action
O: upper head= roof of temporal fossa, lower head= sphenoid bone
I: neck of mandible
A: protrusion and side to side movements, lower head= depression of mandible
For medial pterygoid muscle, give its:
Origin
Insertion
Action
O: superficial head= maxillary tuberosity and palatine, deep head= sphenoid bone
I: ramus of mandible
A: elevates mandible, side to side movement
Which muscles help protract the mandible? What movement is this?
Lateral and medial pterygoids
Protraction = jaw forwards
Which muscles help retract the mandible? What movement is this?
Geniohyoid, digastric, some fibres from temporalis and masseter
Retraction = jaw backwards
What muscles are involved in depression of the mandible?
Digastric
Geniohyoid
Myohyoid
Lateral pterygoid
= assisted by gravity and relaxation of muscles of mastication (apart from LP)
Which muscles are involved in elevation of the mandible?
Temporalis
Masseter
Medial pterygoid
What is the role of the parotid gland?
Bilateral salivary gland that produces serous saliva, a watery solution rich in enzymes - secreted into oral cavity where it lubricates and breaks down food
What are the boundaries of the parotid gland?
Superiorly: zygomatic arch
Inferiorly: inferior border of mandible
Anteriorly: masseter muscle
Posteriorly: external ear and sternocleidomastoid
Where do secretions of the parotid gland travel? I.e. what muscles does it pass on its route
Within the parotid (‘stensen’) duct - traverses the masseter and pierces the buccinator, opens into oral cavity near 2nd upper molar
What branches does the facial nerve give off when in the parotid gland?
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical
What else gives off branches within the parotid gland? Name the branches
External carotid artery ascends through then gives off:
- Posterior auricular, which then divides into the maxillary and superficial temporal artery
What is responsible for venous drainage of the face?
Retromandibular vein: formed by maxillary and superficial temporal veins
Facial vein: continuation of angular vein
= join to form common facial vein
What is responsible for arterial supply to the face?
Maxillary and superficial temporal arteries
What cranial nerve provides parasympathetic innervation to the parotid gland?
Glossopharyngeal (IX)
What provides sympathetic innervation to the parotid gland? What is its action?
Superficial cervical ganglion
When stimulated, it reduces saliva secretion via vasoconstriction
What nerve provides sensory innervation to the face? Where are the muscles it innervates derived from?
Branches of trigeminal
1st pharyngeal arch
Where do the branches of the ophthalmic nerve provide sensory innervation to?
Supraorbital and supratrochlear: upper eyelid, forehead and scalp
Infratrochlear: medial upper eyelid and side of nose
Lacrimal: lateral upper eyelid
External nasal: anterior part of nose
Where do the branches of the maxillary nerve provide sensory innervation to?
Zygomaticotemporal: temple above zygomatic arch
Zygomaticofacial: area over zygomatic bone
Infraorbital: lower lid, cheek, side of nose and upper lip
Where do the branches of the mandibular nerve provide sensory innervation to?
Auriculotemporal: external auditory meatus, tympanic membrane, temple
Buccal: surface of cheek
Mental: lower lip and chin
What provides motor innervation to muscles of the face? Where are these muscles derived from?
Facial nerve
2nd pharyngeal arch
Where do the branches of the facial nerve supply?
Temporal: muscles in temple, forehead and supra-orbital areas
Zygomatic: muscles in intra-orbital, lateral nasal and upper lip areas
Buccal: muscles in cheek, upper lip and corner of mouth
Marginal mandibular: muscles of lower lip and chin
Cervical: supplies the platysma
What is the main arterial supply of the face?
External carotid artery, but it anastomoses with the internal carotid artery around the orbit
What are the anterior branches of the ECA?
Superior thyroid
Lingual
Facial artery
What are the posterior branches of the ECA?
Ascending pharyngeal - to pharynx
Occipital - back of scalp
Posterior auricular - behind ears
What are the branches of the facial artery and where do they supply?
Inferior and superior labial - to lower/upper lip
Alar artery - to nose
Lateral nasal artery - over bridge of nose
Angular artery - to eyes (terminating branch)
What does the temporal branch of the facial nerve innervate?
Frontalis, orbicularis oculi, corrugator supercilli
What does the zygomatic branch of the facial nerve innervate?
Obicularis oculi
What does the buccal branch of the facial nerve innervate?
Obicularis oris, buccinator, zygomaticus
What does the marginal mandibular branch of the facial nerve innervate?
Mentalis, depressor labii inferioris, depressor anguli oris
What are the extrinsic tongue muscles and their roles?
Genioglossus - stick tongue out (protrude)
Hyoglossus - depress tongue
Styloglossus - elevate and retract tongue
Palatoglossus - depresses soft palate
What innervates the tongue muscles?
Hypoglossal nerve to all except palatoglossus (via vagus nerve)
Name the intrinsic tongue muscles, where their fibres run and their roles
Longitudinal - run length of tongue, curl edges and tip in
Transverse - runs from side to side, curls tongue in
Vertical - up and down, so makes tongue wider or flattens it
What is the foramen caecum?
Depression at back of tongue
What is the sulcus terminalis?
V-shaped bit at back of tongue that seperates papillae from larger papillae
What arteries supplies blood to area around your eyes?
Supratrochlear and supraorbitla branches of ophthalmic (from ICA)
