Anatomy Flashcards
Explain the main features of mastication and ingestion of food?
An anterior oral seal is provided by the lips and the orbicularis oris muscle.
- Food gathers on the tip of the tongue & the tongue retracts pulling food back to the posterior teeth.
- The tongue rotates to position the bolus on the occlusal table. Breakdown of food by the teeth & saliva.
- The tongue moves forward and contacts with the hard palate. This contact moves backwards moving the food back through the fauces onto the pharyngeal surface (squeeze back mechanism)
- Food remains on the pharyngeal surface until swallowing occurs. A posterior seal holds liquid in the back of the mouth.
- Swallowing through involuntary movement to push the bolus through the pharynx to the oseophagus. Persitalsis occurs to move food towards the stomach.
What biological factors affect masticatory performance of humans?
Sufficient dentition (number of occluding teeth)
What foramen does the opthalmic branch of the trigeminal nerve pass through?
the superior orbital fissure
What foramen does the maxillary branch of the trigeminal nerve pass through?
foramen rotundum
What foramen does the mandibualr branch of the trigeminal nerve pass through?
foramen ovale
List the cranial nerves and how you would examine each. (12)
Olfactory
cover one nostril and ask px to breathe in and out from the nostril = shows patency (repeat this on the other side)
Cover one nostril and present a smell = ask patient to identify (repeat on other side)
Optic
visual acuity: close one eye and read the letters on the chart, repeat on other side, repeat with both eyes open.
Visual fields: Ask patient to count the no. of fingers you’re holding up on either side
Papillary reflexes: use light to shine into one eye and asses the contraction of the pupil on both sides at same time.
Blink to threat test: try to hit px’s face and see if they react/flinch eyes
Oculomotor/trochlear/abducents
assess gaze at rest: ensure no deviation and both are central
Ask patient to follow your finger with their eyes (ensure no double vision)
Trigeminal
light touch test on all 3 divisions
Pinprick test (assess response to a more “painful” stimuli)
Clench jaw = temporalis and masseter
Open mouth and try to resist you pushing it closed = pterygoids
Jaw jerk reflex
Facial
assess facial asymmetry
Puff out cheeks
Scrunch eyes
Smile with teeth
Raise eyebrows
Vestibulocochlear
auditory acuity: cover one ear and rub fingers next to ear - progressively move further away.
Glossopharyngeal/Vagus
gag reflex
Cough reflex
Swallowing water
Say aaaah and assess symmetry of the uvula and soft palate
Taste (post 1/3rd)
Accessory
get patient to turn their head to LHS/RHS and ask them to try to resist your hand against their face trying to move to the opposite side
Get patient to shrug shoulders and you resist the movement
Hypoglossal
get patient to stick tongue out, to RHS and then to LHS
Get them to stick tongue into the cheek and you push down on it extra-orally
what is the nerve supply to the submandibular gland?
Parasympathetic innervation from the chorda tympani branch of facial nerve which unifies with lingual branch of mandibular nerve at the submandibular ganglion.
what is the nerve supply to the sublingual gland?
Parasympathetic – chorda tympani of facial nerve which unifies with lingual branch of mandibular nerve at submandibular ganglion.
what is the nerve supply to the parotid gland?
Sensory innervation – auriculotemporal nerve and greater auricular nerve
o Parasympathetic – glossopharyngeal nerve and auriculotemporal nerve
What is the origin, insertion, innervation and function of the muscles of mastication:
Masseter:
o Origin – zygomatic arch
o Insertion – lateral surface and angle of mandible
o Action – elevates and deep fibres retrude mandible
o Testing – clench teeth together
o Innervation – masseteric branch of mandibular division of trigeminal nerve
- Temporalis:
o Origin – floor of temporal fossa
o Insertion – coronoid process and anterior border of Ramus
o Action – elevates and retracts mandible
o Testing – clench teeth and palpate all fibres (anterior, middle and posterior)
o Innervation – anterior division of deep temporal nerve branches of mandibular
division of trigeminal nerve - Medial pterygoid:
o Origin – deep head medial surface of lateral pterygoid plate
o Insertion – medial surface of angle of mandible
o Action – elevates and assists in protrusion of mandible
o Testing – intra oral can be painful
o Innervation – nerve to medial pterygoid of the mandibular division of trigeminal
nerve - Lateral pterygoid:
o Origin – lateral surface of lateral pterygoid plate and base of skull
o Insertion – pterygoid fovea and some fibres extend into the capsule of the TMJ
independent heads – inferior to head of consult; superior to intra articulate disc
o Testing – response to resisted movement by putting finger far back of maxilla
and move jaw side to side
o Innervation – anterior division nerve to lateral pterygoid branch of mandibular
division of trigeminal nerve
List the intrinsic muscles of the tongue (4)
Longitudinal (superior and inferior) = curl upwards or downwards
vertical = flattens
transverse = elongates/narrows
list the extrinsic muscles of the tongue (4)
palatoglossus
styloglossus
genioglossus
hyoglossus
action: protrude, retract, elevate and depress
what nerve provide motor sensation to the muscles of the tongue?
motor = Hypoglossal nerve
except palatoglossus = vagus
what nerves supply the sensation to the tongue?
Anterior 2/3rds
taste = chorda tympani
sensory = lingual nerve, mandibular branch of the trigeminal
posterior 1/3rd = glossopharyngeal
LABEL BRANCHES OF TRIGEMINAL NERVE
