Class 8 Flashcards
What are the features of the Occipital bone?
• external occipital protuberance (inion)
• foramen magnum
• occipital condyles
• superior nuchal line
• inferior nuchal line
What are the features of the Nasal bones?
• bridge of the nose
What are the features of the Maxillae?
• frontal process
• zygomatic process
• orbital surface
• alveolar processes
• infraorbital foramen – exit of infraorbital nerve
• palatine process
What is the Maxillae?
• skeleton of face between mouth and eyes
What are the Zygomatic bones?
• cheek bones
Key features of the Zygomatic bones?
• anterolateral & infra orbital margins
• temporal process (of zygomatic bone)
What is the Ethmoid bone?
• separates nasal cavity from brain
• located at roof of nose between orbits
• crista galli – ridge of bone projecting superiorly- attachment for falx cerebri (arched fold of dura mater which separates right & left hemispheres of brain descends in longitudinal fissure)
• cribriform plate
• perpendicular plate – forms posterior & superior part of nasal septum
What is the crista galli of Ethmoid bone?
Ridge of bone projecting superiorly - attachment for falx cerebri (arched fold of dura mater which separates right & left hemispheres of brain descends in longitudinal fissure)
What is the perpendicular plate of Ethmoid bone?
Forms posterior & superior part of nasal septum
What are the key features of sutures?
• coronal suture
• sagittal suture
• bregma: meeting point between coronal & sagittal sutures
• squamous suture - joint between temporal & parietal bones
• lambdoid suture
• lambda: meeting point of lambdoid & sagittal sutures
• pterion: connection between sphenoid, temporal, frontal & parietal bones
What is the bregma of sutures?
meeting point between coronal & sagittal sutures
What is the squamous suture?
joint between temporal & parietal bones
What is the lambda of sutures?
meeting point of lambdoid & sagittal sutures
What is the pterion of sutures?
connection between sphenoid, temporal, frontal & parietal bones
Coronal Suture is the dividing line between the ______________________ and the ______________________.
frontal bone and the parietal bone
What is the orbital socket?
• eye socket
• cone-shaped cavity
• made of many bones
• optic canal
What is the key features of the orbital socket?
• posterior wall - sphenoid
• floor - maxillae
• roof - frontal
• lateral wall - zygomatic
• medial wall - ethmoid
What are the Sinuses?
• frontal (2)
• sphenoidal (2)
• ethmoidal (2)
• maxillary (2) (largest)
• air travelling through sinuses is either warmed or cooled to within 1 deg of body temp
• there are short, thick hairs called vibrassae which help to move particulate matter - (dust etc)
What are vibrassae?
Short, thick hairs - help to move particulate matter (dust etc)
What is The Temporomandibular Joint (TMJ)?
• head/condyle of mandible articulates with mandibular fossa & articular tubercle of temporal bone
• synovial
• modified hinge
What is the Articular Disc (Temporomandibular Joint)?
• fibrocartilagenous disc sits between head of mandible &
temporal bone (2 articulating surfaces)
• connected to joint capsule (capsule is quite loose & thin)
• follows movements of mandible
• attached to disc posteriorly is the retrodiscal pad - helps maintain proper positioning of disc
What are the ligaments of the temporomandibular joint?
• joint is supported by capsule
• capsule thickens laterally to form lateral (temporomandibular) ligament
• stylomandibular ligament
• sphenomandibular ligament
What are the available movements of the temporomandibular joint?
• depression: opening mouth
• elevation: closing mouth
• protraction/protrusion: anterior translation of mandible
• retraction/retrusion: posterior translation of mandible
• deviation: movement from side to side
What are the Attachments of Temporalis?
• superior attachment: temporal bone (fossa)
• inferior attachment: coronoid process & anterior ramus
What are the Actions of Temporalis?
• action: elevation of mandible
• action: retraction of mandible (more horizontal/posterior fibres)
What are the attachments of the Masseter?
• note: superficial & deep fibres
• superior attachment: inferior border of zygomatic arch
• inferior attachment: angle of mandible
What are the actions of the Masseter?
• action: elevation of mandible
• action: (superficial fibres) protraction of mandible
• action (deep fibres): retraction of mandible (from protracted position)
What are the attachments of the Lateral pterygoid?
• note: superior head & inferior head
• anterior attachment: greater wing of sphenoid (superior head) & lateral surface of lateral pterygoid plate (inferior head)
• posterior attachment: neck of mandible (inferior head), articular disc (superior head)
What are the actions of the Lateral pterygoid?
• action: protraction of mandible
• action: translational (anterior/posterior) control of articular disc (superior head)
• action: depression of mandible (inferior head) (once translation occurs)
• action: contralateral deviation of mandible
What are the attachments of the Medial pterygoid?
• anterior attachment: medial surface of lateral pterygoid plate
• inferior attachment: pterygoid tuberosity (inner surface of angle of mandible)
What are the actions of the Medial pterygoid?
• action: elevation of mandible
• action: protrusion of mandible
• action: contralateral deviation of mandible
What are the actions of Hyoids?
• action (hyoid fixed): assist in depression of mandible
What are the muscles of mastication that do depression?
• hyoids
• lateral pterygoid (inferior head) (once translation occurs)
What are the muscles of mastication that do Elevation?
• temporalis
• masseter
• medial pterygoid
• lateral pterygoid (superior head) (eccentric control of disc return)
What are the muscles of mastication that do Protrusion?
• masseter (superficial fibres)
• lateral pterygoid
• medial pterygoid
What are the muscles of mastication that do Retrusion?
• temporalis (posterior fibres)
• masseter (deep fibres)
What are the muscles of mastication that do Deviation?
• contralateral pterygoids
What are the Biomechanics of the TMJ (Depression (opening the mouth)?
• beginning to midrange of motion is primarily anterior sagittal rotation of head of mandible in mandibular fossa
• midrange to end range is primarily anterior translation of head of mandible from fossa onto articular tubercle
• as translation occurs, articular disc is pulled anteriorly by superior head of lateral pterygoid to maintain joint surface congruency
• muscles activated include: digastric, mylohyoid, geniohyoid, & when translation occurs, inferior head of lateral pterygoid
What are the Biomechanics of the TMJ (Elevation (closing the mouth)?
• posterior translation of mandibular head from articular tubercle to fossa followed by posterior sagittal rotation of mandibular head in mandibular fossa
• as mouth closes, disc is pulled back into position by elastic fibres that attach to back of disc – movement is controlled (eccentrically) by superior head of lateral pterygoid
• muscles activated include: masseter, medial pterygoid, temporalis, superior portion of lateral pterygoid
What are the Biomechanics of the TMJ (Deviation)?
• muscles activated include: contralateral medial pterygoid, contralateral lateral pterygoid
What are the Biomechanics of the TMJ (Protraction)?
• medial pterygoid, masseter, lateral pterygoid
What are the Biomechanics of the TMJ (Retraction)?
• temporalis, & deep fibres of masseter
What is a Close packed position of TMJ?
• maximal occlusion
What is a Resting position of TMJ?
• teeth 2-5mm apart with the tip of tongue resting behind front teeth on roof of mouth
What is OCCIPITOFRONTALIS?
• occipitalis (2 bellies): superior nuchal line - epicranial aponeurosis
• frontalis (2 bellies): skin near eyebrows - epicranial aponeurosis
• action: occipitalis anchors aponeurosis so that frontalis can pull eyebrows up
What is ORBICULARIS OCULI?
• sphincter of the eye – contraction closes eyelids
• helps to empty lacrimal (tear) sac (tearing)
What is Corrugator supercilii?
• draws eyebrows inferiorly & medially
What is Levator labii superioris?
• raises upper lip
What is Levator labii superioris aleque nasi?
Levator labii superioris aleque nasi
What is Zygomaticus minor?
• raises upper lip
What is ZYGOMATICUS MAJOR?
• draws angle of mouth superolaterally
What is ORBICULARIS ORIS?
• sphincter of the mouth
• fibres are derived from other muscles
• closes the lips
• protrudes lips
• compresses lips against teeth
What is MENTALIS?
• raises & protrudes lower lip
What is Depressor labii inferioris?
• draws lip inferiorly & slightly laterally
What is Depressor anguli oris?
• depresses corner of the mouth
What is BUCCINATOR?
• compresses cheek against molar teeth when chewing (keeps food where teeth can grind it)
• helps with whistling (forceful blowing)
What is PLATYSMA?
• retracts & depresses angle of the mouth
What is the Auricularis anterior?
• draws ear up & forward
What is the Auricularis superior?
• draws ear up
What is the Auricularis posterior?
• draws ear back
(Muscles of facial expression summary) Occipitofrontalis = _____________________
Surprise
(Muscles of facial expression summary) Orbicularis oculi = _____________________
Squinting & winking
(Muscles of facial expression summary) Corrugator supercilii = _____________________
Frowning
(Muscles of facial expression summary) Levator labii superioris = _____________________
Snarling
(Muscles of facial expression summary) Levator labii superioris aleque nasi = _____________________
Stank face
(Muscles of facial expression summary) Zygomaticus minor = _____________________
Elvis
(Muscles of facial expression summary) Zygomaticus major = _____________________
Smiling
(Muscles of facial expression summary) Orbicularis oris = _____________________
Kissing & whistling
(Muscles of facial expression summary) Mentalis = _____________________
Pouting
(Muscles of facial expression summary) Mentalis = _____________________
Pouting
(Muscles of facial expression summary) Depressor labii inferioris = _____________________
Yikes
(Muscles of facial expression summary) Depressor anguli oris = _____________________
Sad
(Muscles of facial expression summary) Platysma = _____________________
Creature from black lagoon
