ANATOMY HNS; Lecture 4, 5 and 6 - Face and Oral cavity, Upper airway and digestive tract, Eye and orbit Flashcards
What are the features observed in the mouth when oral cavity inspection occurs?
Uvula, oropharynx (posterior wall), frontal fold in mouth is palatoglossal and posterior is the palatopharyngeal which when contracted helps with swallowing; palatine tonsil is a lymph node
How do you test vagus nerve function in the oral cavity?
Uvula should move into the midline when saying ‘Ah’ -> if compromised uvula moves away from damaged side
How does the epiglottis aid in swallowing?
Retroflexes to cover the laryngeal inlet to stop you choking on food
How does the hard palate aid in swallowing?
Provides a hard surface on which to push food onto to break it up more easily
What are the features of the oral cavity which can be seen in a midline section?
What are the features of the oral cavity which can be seen in the posterior view?
NB: piriform fossa which is where a lot of fish bones get stuck and it is highly innervated causing a lot of pain
What are the sections of the pharynx?
Nasopharynx, oropharynx, laryngopharynx, superior; middle and inferior constrictors (sensory IX, X (pharyngeal plexus); motor X/xi,) all aiding in swallowing
How does swallowing work?
Lift and retract tongue (styloglossus, intrinsic muscles of tongue), bolus into oropharynx (palatoglossus retraction), close off nasopharynx by raising soft palate, raise larynx which is closed off by epiglottis, peristaltic wave of constrictor muscles, relax cricoharyngeus and open oesophagus
What are the 3 salivary glands?
Parotid (mainly serous) IX which goes through parotid duct, opening upper second molar; submandibular (mainly serous) VII, sublingual (mainly mucous) VII
What are the muscles in the tongue?
Syloglossus, hyoglossus, genioglossus (protraction of tongue), intrinsic muscles -> supplied by CN XII
What are the features of the tongue and surrounding muscles in a sagittal section?
NB: Mylohyoid is the floor of the mouth; submandibular ganglion is PS ganglion involved in saliva secretion
How do you test CN XII and what would you see if there was a lesion on one side?
Stick the tongue out, which should be in the middle and tongue moves toward the side of the lesion, if chronic, the muscle on that side will have atrophied
How is the tongue innervated?
Tactile sensation in the trigeminal nerve; with anterior 2/3rds is taste and facial nerve; and in posterior 1/3rd of tongue both touch and taste is pharyngeal; end of tongue is vagus which is both again
What are the superficial muscles of mastication?
Masseter (zygomatic arch to lat surface of ramus and angle of mandible); temporalis (temporal fossa to coronoid process of mandible)
What nerve supplies the superficial muscles of mastication?
Trigeminal except buccinator muscle which is supplied by the facial muscle
What are the deep muscles of mastication?
Lateral pterygoid -> sphenoid/lat pterygoid plate to neck of mandible; medial pterygoid -> lat pterygoid plate/maxilla/palate to angle of mandible
What is the function of the medial pterygoid?
Elevates, protracts and lateral movement of mandible for chewing
What is the function of the lateral pterygoid?
Depresses and protracts the mandible to open mouth
What is the function of the Masseter muscle?
Elevating mandible allowing forced closure of mouth
What is the function of the Temporalis muscle?
Elevates and retracts the mandible
What is the TMJ?
Articular disc and capsule around the joint -> hinge action on joint, gliding action on articular tubercle when opened a bit more -> anterior dislocation of jaw can be problematic due to the blood supply in the cavity
What is the blood supply to the face area coming off the external carotid artery (some anatomists like freaking out poor medical students)?
Superior thyroid artery, ascending pharyngeal, lingual, facial (big loop so that it doesn’t become tense when opening the jaw causing rupture of the artery), occipital, posterior auricular, maxillary, superficial temporal
What are the 5 main branches of the facial nerve going to the face?
NB: Parotid gland gets innervation from glossopharyngeal NOT from Facial
What is the mandibular nerve?
Inferior alveolar nerve (lies in mandible and emerges out onto chin - called mental nerve), stimulated by toothache; lingual nerve is sensation to ant 2/3rd of tongue, but joins to facial (chorda tympani) nerve
How are the dermatomes organised in the head and neck?
How can you test function of V1?
Opthalmic division -> touching forehead, nose
How can you test function of V2?
Maxillary division -> On cheek
How can you test function of V3?
Mandibular division -> on chin
What are the conchae (superior, middle and inferior)?
Increase SA to warm the air and expose the air to the immune system to trap pathogen, covered in respiratory epithelium
What are the nasal cavities?
Upper part of resp tract; ant and post regions; contain conchae
What is the function of nasal cavities?
Warm and humidify air, help trap pathogens
Which bones make up the conchae?
x
How is the nasal cavity innervated (olfaction, regions, glands and vascular smooth muscle)?
Olfaction: Olfactory nerve; Trigeminal nerve: V1 anterior region and V2 posterior region; Facial nerve innervates glands (mucous membrane); sympathetic nerves from T1 innervate vascular smooth muscle
What is the blood supply to the nasal cavities?
Internal/External carotid
How is the nasal cavity drained?
Where are the paranasal sinuses located?
Filled with air, decrease weight of skull, help with transmission of sound, acts as a crumple zone for protection of brain
What do the sinuses look like in an x-ray?
NB: maxillary sinus can be easily infected when teeth taken out or when dental abscess occurs
Where do the sinuses drain into?
Into the nasal cavity (lacrima drains into the (nasolacrimal) nasal cavity)
What is the larynx?
Hollow structure composed of cartilages, membrane and muscles
What is the function of the larynx?
Valve and sound producer
What are important cartilages of the larynx?
Laryngeal cartilage, thyroid cartilage, laryngeal prominence
What do the laryngeal cartilages look like?
Thyroid cartilage sits on top of cricoid cartilage, rocking backwards and forwards which can change the tension of the vocal cords (as well as action of muscles)
What are the vocal folds?
Vestibular fold (false vocal fold) and vocal fold (true vocal fold)