Biting, chewing and swallowing - oral cavity Flashcards
Name two fold of tissue which contain the palatine tonsil between them
palatopharyngeal fold
palatoglossal fold
How can damage to the back of the pharynx spread infection?
Can spread infection into the thoracic cavity
What are the 2 types of palates in the mouth
Hard and soft
Which palate is the uvula part of?
soft
What does deviation of the uvula suggest?
dysfunction of the vagus on the opposite side
Where does the oesophagus open in relation to the airway?
posterior to the airway
What happens during swallowing to prevent food going down the trachea?
The larynx is raised and the epiglottis retroflects to cover the airway.
What is the use of the hard palate?
The hard palate is bone – this is useful in mastication. When you chew food, pushing it against the hard palate helps to break it down before swallowing
What is the importance of the piriform fossa in the laryngopharynx?
Food can get caught here (particularly fish bones).
This area has a very sensitive innervation so this is very painful. You sometimes have to use forceps to try and extract fish bones.
What are the constrictor muscles of the larynx and their innervation?
Within the pharynx are the superior, middle and inferior constrictor muscles
They allow pushing of food downwards into the GI tract – sequential contraction
Sensory IX, X supply to the pharyngeal plexus
Motor activity is largely due to X innervation (XI as well)
What is the process of swallowing?
- Lift and retract the tongue (controlled by the styloglossus and intrinsic)
- Bolus is moved into the oropharynx (contraction of palatoglossus)
- Elevate the soft palate (levator muscles) – this closes off the nasopharynx (stops food going into nose)
- Raise the larynx, to close off the epiglottis – stops food going into the airway
- Peristaltic wave of constrictor muscles (superior, middle and inferior constrictors) – moves bolus down
- Relax cricopharyngeus (UOS) -> this opens the oesophagus to allow passage for food
How many pairs of salivary glands are there and what are they?
3 - parotid, submandibular, sublingual
What kind of saliva does each salivary gland produce?
parotid - thin, serous
submandibular - serous
sublingual - mucous
Where do each of the salivary glands get input from?
Parotid - cranial nerve 9
Submandibular - cranial nerve 7
Sublingual - cranial nerve 7
How does saliva pass from the parotid gland to the mouth and where?
Via the parotid duct and opens next to the second upper molar
What are the muscles of the tongue?
Styloglossus - helps retract tongue
Hyoglossus
Genioglossus - from tongue to mandible, contraction helps prortrude tongue
Intrinsic muscles
Which is the only motor nerve supplying the tongue?
The hypoglossal
How can you test for the hypoglossal nerve?
The genioglossus contracts on either side and if there is deviation of one side of the tongue it means that the same side of hypoglossal is affected
What does the lingual nerve (branch of v3 - trigeminal mandibular branch) do?
Has mixed cranial components and supplies the tongue with touch sensation and taste perception
Trigeminal and facial fibres (chorda tympani ) are all together in the lingual nerve (multifunctional nerve)
Which nerve provides sensation to the anterior two third of the tongue?
V3 - trigeminal
Which nerve supplies the taste fibres to the anterior two thirds of the tongue?
facial nerve - chorda tympani
Where is taste perception processed?
The nucleus solitaries in the brainstem
Which nerve provides sensation and taste to the posterior third of the tongue?
glossopharyngeal - little also from the vagus
What are the muscles of mastication (superficial) and their locations?
Masseter - from the zygomatic arch to lateral surface of ramus and angle of mandible (side and the corner)
Temporalis - from temporal fossa to coronoid process of mandible
What are the muscles of mastication (deep) and their locations?
Lateral pterygoid - connects from sphenoid/lateral pterygoid plate to neck of mandible
Medial pterygoid - lateral pterygoid plate/maxilla/palate to angle of mandible
Name another muscle of mastication and its location
Buccinator - between maxilla and mandible
What is the temporal fossa?
shallow depression on the side of the skull
What is the zygomatic arch?
cheek bone
What innervates the superficial muscles of mastication?
mandibular division of the trigeminal
What innervates the deep muscles of mastication?
mandibular division of the trigeminal