Anatomy of biting, chewing and swallowing Flashcards
Buccal cavity?
=mouth
2 folds in the mouth
Palatopharyngeal fold (palate to pharynx) Palatoglossal fold (palate to tongue)
Locate the palatine tonsil
Between palatopharyngeal and palatoglossal fold
Posterior wall of the oral cavity
Oropharynx
What is the uvula
part of the soft palate
Why do doctors ask you to say ‘ahh’
Tests the vagus nerve (which provides most motor innervation to the levator palatine muscle)…. the soft palate incl. uvula should lift up….
What occurs if there is a problem with vagus nerve on one side of the soft palate
Levator palatine muscle won’t elevate, but the levator palatin muscle on the other side (where vagus is functioning) will elevate normal, so uvula will deviate towards the functioning side (which goes up!), so uvula will deviate AWAY from the lesion
(OPPOSITE with tongue)
3 components of the pharynx
Naso-, oro- and laryngo… posterior to airway is opening of eosophagus
Pharyngeal isthmus between naso-oro
Epiglottis between oro-laryngo
How is food stopped from going down airway
You will raise the layrnx, you retroflex the epiglottis and cover the airway
What is the hard and soft palate
Hard palate anterior, made up of formed by the palatine process of the maxilla and horizontal plate of palatine bone, and spans the arch formed by the upper teeth
Soft palate posterior with uvula in the midline
Area where food can get stuck inc. fishbones
Piriform fossa… on either side of the laryngeal orifice
Muscles of the pharynx and function
Constrictor muscle… pushes bolus into GI tract by sequential contraction…. (sup, mid, inf)
Sensory IX and X (pharnyngeal plexus= sensory)
Motor X (XI), constriction
Outline stages of swallowing
Lift and retract tongue (styloglossus, intrinsic)
Bolus into oropharynx (palatoglossus- surface representatin is the palataoglossal food)
Close off nasopharynx by raising soft palate
Raise the larynx, closed off by epiglottis
Peristaltic wave of constrictor muscles X and (XI)
Relax cricopharyngeus, open oesophagus
3 pairs of slaivary glands
Parotid (biggest), submandibular and sublingual
What type of liquid comes from each salivary gland
Parotid and submandibular mainly serous, sublingual maily mucus
Which cranial nerves are each salivary gland supplied by
Parotid- IX
Submandibular and sublingual- VII
FACIAL NERVE EMERGES from the parotid, but the facial nerve DOES NOT innervate it
Where does the fluid drain into mouth from parotid gland
Via parotid duct, which opens above the upper second molar
Which muscle does the parotid canal penetrate to get to second molar
Buccinator muscle
List the muscles of the tongue
styloglossus - to styloid process = help to retract
hyoglossus (to hyoid)
genioglossus (to mandible)
intrinsic muscles
Which cranial nerve supplies motor innervation to muscles of the tongue
XII
Apart from palatoglossus (vagus CNX)
What is the attachment and function of genioglossus
To protrude the tongue….
Genioglossus emerges from mandible (anteriorly) and inserts onto tongue and hyoid bone…
It protrudes the tongue when this muscle contracts (kind of pulls it forward towards mandible when this muscle shortens)
How to test genioglossus,. what is there is a problem with the nerve supplying this msucle
Ask them to stick tongue out…. if there is no innervation, the tongue is pulled forward on one side and not the other, and it pulled TOWARD the lesion
What is the lingual nerve function
Sensation as well as taste perception… mixed cranial nerve
What is the name of the ganglion under the tongue
Submandibular ganglion…. vagus innervation to salivary gland
Compare the sensation vs taste innervation of the tongue
ANT 2/3. Taste= facial. Sensory= trigeminal
Posterior 1/3. Taste and sensation= glossopharyngeal….. SOME vagus
Where does taste perception begin…
nucleus solitarius in medulla
List superficial muscles of mastication and innervation
Masseter
zygomatic arch to lat surface of ramus and angle of mandible
elevates mandible (allows forced closure of mouth)
Temporalis- THIN
temporal fossa to coronoid process of mandible
elevates and retracts mandible
All mastication from trigeminal
List deep muscles of mastication and innervation
Lateral pterygoid:
- sphenoid /lat pterygoid plate to neck of mandible
- depresses and protracts mandible to open mouth
Medial pterygoid
- lat pterygoid plate of sphenoid/ maxilla/palate to angle of mandible
- elevates, protracts and lateral movement of mandible for chewing
Trigeminal
(vs buccinator is cn7)
Where does the mandible articulate in the temperomandibular joint
It articulates into the mandibular fossa of the temporal bone
What kind of joint is the temperomandibular joint
Joint capsule
Two synovial cavities separated by articular disc
Other importnat component of the temporomandibular joint
the articular tubercle anteriorly
State the movement in the temporomandibular joint when opening the jaw slightly vs widely
Slightly- hinge action between the head of the mandible and the mandibular fossa of the temporal bone
Widely opened- both hinge movement within the mandibular fossa, but the head of the mandible also GLIDES anteriorly to the articular tubercle of the temporal bone
Reason of articular disc = allow protrusion/retraction as well as elevation/depression
What can occur in anteriotly dislocated jaw dyslocation
Jaw opens so widely that it glides across the articular tubercle of temporal bone into the infratemporal fossa (where there are vessels and nerves)
How can you put mandible back in place
Must put thumbs on back molars, push down (to get passed the articular tubercle) and then back into the mandibilar fossa
At what level does the common carotid bifurcate
Laryngeal prominence
Branches of the external cartotid artery
Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior auricular Maxillary Superficial temporal
What does thesuperior thyroid penetrate
thyroid cartilage
Why is ascending pharyngeal artery hard to see
It originates posteriorly
Route of the facial artey
Around the inferior border of the mandible up to medial canthas of the eye
It has a loop that allows lovement as it goes around the mandible which is alwayss opening and closing
Which important artery emerges from the maxillary artery
The middle meningeal artery—-> this branch comes through formaen spinosum
What is the course of the facial nerve when it exits the
It emerges from pontomedullary junction,and then passes through the interal auditory meatus with the vestibulocochlear nerve.
It passes through the temporal bone and emerges from the stylomastoid foramen
Passes underneath the parotid and then the 5 branches of the facial nerve emerge from the anterior border of the parotid gland….. PAROTID GLAND IT NOT INNERVATED BY THE FACIAL NERVE
List the 5 branches of the facial nerve emerging from the parotid
Temporal, zygomatic, buccal, mandibular and cervical (supplying the platysma)
You can test facial nerve by asking them to look up and should have creases in forehead
Name the course and then two branches of the mandibular nerve
Mandibular nerve passes through thhe foramen ovale and then splits into:
- Inferior alveolar nerve…. passes into the back of the mandible and it travels through the mandible. Sensory nerve for lower dentition.
- The lingual nerve supplies sensory innervation to anterior 2/3 so contains V3 fibres. But it also has facial nerve branches from the chorda tympani (branch of the facial nerve emerging in the temporal bone). Information flow in chorda timpani bidiretional…. they are parasympathetic to submandibular ganglion (to submandibular and sublingual salivary gland) AND taste fibres from the anterior 2/3 of the tongue!!!!
What is the terminal branch of the inferior alveolar nerve
The mental nerve (relating to mens=chin)
How to test V3
sensory to the chin
Dermatomes of head and neck
V1 = forehead + eyeball (corneal reflex)
V2 = below eyes + nose + cheeks + upper teeth
V3 = lower teeth + tongue + chin + thin strip of skin on lateral side of face going up to temples (think of sideburns)
Posterior of head is C2-C3
Neck is C4-C5
Innervation of the buccal caviy
Hard palate: Greater palatine, nasopalatine nerves (both V2)
Soft palate: lesser palatine nerve (V2)
Floor of oral cavity: lingual nerve (V3)
Cheeks: Buccal nerve (=V3, distinct from buccal branch of facial nerve!)
What is the name and function of the recess at the back of the tongue
Epiglottice vallecula (recess which allows saliva to collect until next swallow so the saliva doesn’t constalty evoke a swallow reflex)
