Oral and Nasal Region

palatine tonsils

inflammation of these tonsils is associated with difficulty swallowing and a sore throat, because these tonsils are visible when inspecting the oral cavity they may appear enlarged and red, these tonsils may be removed in a tonsilectomy to ensure the patient can swallow and breathe properly

supratrochleaar and infratrochlear branches of the ophthalmic nerve (V1)

innervate the skin of the root, bridge, and the upper part of the side of the nose

vagus nerve (CN X)

innervates all the muscles of the soft palate with the exception of tensor veli palatini

infraorbital branch of the maxillary nerve (V2)

innervates the skin on the side of approximately the lower half of the nose

anterior ethmoidal nerve (V1)

innervates the skin over the dorsum and tip of the nose

action of the buccinator muscle

is opposed by the tongue and holds food between the teeth during mastication

palatine foramina

openings in the palatine bone that transmit the greater and lesser palatine

pterygopalatine ganglion

receives preganglionic parasympathetic secretomotor fibers from the greater petrosal nerve (CN VII) which synapse here before continuing on to join up with the palatine nerves and supply palatine glands

right and left jugular internal lymphatic trunks

the lymphatics of the tongue parallel the arteries, supply and drain to both these lymphatic trunks, therefore early detection of tongue cancer is imperative

parotid papilla

the opening of the parotid duct which is within the superior oral vestibule

intrinsic muscles of the tongue

these muscles change the shape of the tongue

extrinsic muscles of the tongue

these muscles move the tongue

maxillary nerve (CN V2)

this is a branch of the trigeminal nerve, specifically after the nerve splits into three strands within the basicranium each branch goes through one of three roughly vertically stacked foramina, this is the strand that goes through the middle hole

hypoglossal nerve CN XII

this nerve innervates all the muscles of the tongue

incisive canal

this opening transmits the nasopalatine nerve

CN X

to test the function of this nerve a physician will ask the patient to open his mouth wide to determine if the palate deviates to one side or the other during a yawning motion, a legion of this nerve can cause the paralysis of the ipsilateral levator veli palatini muscle, resulting in the uvula being pulled superiorly to the opposing side of the legion

lingual nerve CN V3 general sensory

- The anterior two-thirds of the tongue receives its general sensory innervation from this nerve - The submandibular duct ascends from the submandibular gland to open adjacent to the lingual frenulum. This nerve courses inferior to the submandibular duct.

submandibular ganglion

- a parasympathetic ganglion and the site of synapse for preganglionic fibers and postganglionic neurons that are secretomotor to the submandibular, sublingual, and numerous small salivary glands in the floor of the mouth

dorsal lingual vein

- accompany the lingual artery

hypoglossal nerve CN XII

- all of the tongue muscles receive their somatic motor innervation from this nerve except the palatoglossus - the largest part of the lingual vein runs along with this nerve

deep lingual vein

- begin at the apex of the tongue, run posteriorly beside the lingual frenulum to join the sublingual vein

palatine tonsil

- blood vessels supply this structure from the front and behind - each of these lies in a tonsillar sinus (fossa) sometimes called a tonsillar bed - tonsillar beds are bounded by the palatoglossal and palatopharyngeal arches and the tongue - lingual tonsils, these tonsils, and pharyngeal tonsils collectively form a ring of lymphoid tissue called Waldeyer's ring

greater palatine nerve

- branch of the maxillary nerve CN V2 - descends through the greater palatine canal of the palatine bone and passes through the greater palatine foramen - innervates the posterior 2/3 of the hard palate and ALSO THE UVULA

lesser palatine nerve

- branch of the maxillary nerve CN V2 which like the other two palatine branches carries parasympathetic secretomotor fibers running with it which originate from the preganglionic secretomotor fibers in the greater petrosal nerve from CN VII which then synapse on the postganglionic secretomotor neurons in the pterygopalatine ganglion - innervates the soft palate and the palatine tonsil

hyoglossus muscle

- courses lateral to the genioglossus muscle, with attachments from the hyoid bone to the tongue - this muscle flattens the tongue and draws down its sides - the lingual artery courses between this muscle and the genioglossus - CN XII AND CN V3 course from the infratemporal fossa to the tongue along the external surface of the hyoglossus muscle

palatoglossus muscle

- forms the palatoglossal arch in front of the palatine tonsil, arising from the soft palate and inserting into the dorsum of the tongue - depresses the soft palate

palatopharyngeal muscle

- forms the palatopharyngeal arch in the back of the palatine tonsil - it elevates the larynx in swallowing being a more prominent muscle

dental branches of inferior alveolar nerve (CN V3)

- local anesthetic can be administered to this nerve during dental procedures and it will block sensation to the mandibular teeth on one side but the maxillary teeth and palate receive innervation from multiple sources that must often be anesthetized seperately

levator veli palatini muscle

- originates along the cartilaginous portion of the auditory tube and inserts into the superior aspect of the soft palate - contraction of this muscle elevates the soft palate and is innervated by CN X - acts together with tensor veli palatini to open up the auditory tube and equalize the pressure in the middle ear

mylohyoid

- originates from the medial body of the mandible - attaches on the hyoid bone - innervated by the mandibular nerve CN V3

styloglossus muscle

- originates on the styloid process of the temporal bone and courses between the superior and middle pharyngeal constrictors to insert on the lateral surface of the tongue, it will retract and elevate the tongue

chorda tympani (from CN VII)

- preganglionic parasympathetic nerves that control secretomotor activity of the submandibular and sublingual glands are within this structure and synapse with the postganglionic neurons in the submandibular ganglion

chorda tympani CN VII special sensory

- provides special sensory innervation (taste) to the tongue - preganglionic fibers originate from the facial nerve

lingual vein

- receives from the sublingual veins to drain into the IJV

musculus uvulae

- shortens the uvula and pulls it superiorly

Lingual nerve (CN V3)

- submandibular and sublingual gland and all glands in the floor of the mouth are innervated by secretomotor postganglionic parasympathetic fibers that reach the glands through this nerve - this nerve is also a general sensory nerve for the anterior 2/3 of the tongue and floor of the mouth -this nerve also carries special sensory (taste) fibers and secretomotor fibers of CN VII that are in the chorda tympani when it joins this nerve in the infratemporal fossa - this nerve enters the floor of the mouth on the medial side of the mandible next to the third molar - this nerve transmits pain, temperature, touch, and pressure sensations in the mucosa on the lingual surface of the mandible and alveolar processes, the floor of the mouth, undersurface of the tongue, and the anterior 2/3 of the dorsum of the tongue

greater palatine artery

- supplies most of the hard palate - this one actually goes through the incisive foramen and anastomoses with the sphenopalatine artery INSIDE THE NASAL CAVITY

deep lingual artery

- supplies the body of the tongue

sublingual artery

- supplies the sublingual gland and other structures in the floor of the mouth

lingual artery

- supplies the tongue - arises from the external carotid artery

glossopharyngeal nerve CN IX

- the posterior third of the tongue receives both its general sensory and special sensory innervation from this nerve - in its course to the tongue, runs along the lateral pharyngeal wall immediately lateral to the tonsil and then runs upward into the posterior part of the tongue, coursing deep to the styloglossus and hyoglossus muscles

submandibular nodes

- the sides of the tongue drain lymph to these nodes and then posteriorly to the internal jugular nodes - jugulodigastric node is a big one of these

submental nodes

- the tip of the tongue drains lymph into this node, then drains posteriorly to the submandibular nodes

anastomosis

- this anastomosis area for the sphenopalatine and greater palatine arteries is often called the Kiesselbach area and is a common site for nosebleeds

genioglossus muscle

- this is a fan shaped muscle arising from the mental spine of the mandible and entering the whole length of the undersurface of the tongue - it keeps the tongue forward in the mouth and prevents the posterior shift of the tongue that can interfere with respiration - when it is paralyzed, the tongue has a tendency to fall posteriorly, obstructing the airway and presenting the risk of suffocation - total relaxation of the this muscle occurs during general anesthesia so an airway has to be inserted in an anesthetized person to prevent the tongue from relapsing - contraction of this muscle allows you to stick your tongue out and physicians can test this by asking you to stick your tongue out

tongue

- this structure consists of skeletal muscle - its surface is covered with taste buds (special sensory) and general sensory nerve endings - it also functions in mastication, degluition (swallowing) and speech - the tongue is supported in the oral cavity by muscular connections to the hyoid bone, mandible, styloid process, palate, and pharynx - the v shaped sulcus terminalis divides the tongue into anterior and posterior divisions, which differ developmentally, structurally, and by innervation - the foramen cecum is located at the apex of the v and indicates the site of origin of the embryonic thyroglossal duct

soft palate

- this structure is continuous with the palatoglossal and palatopharyngeal folds - includes the uvula, the musculus uvulae - its function is to ensure that food moves inferiorly down into the esophagus when swallowing rather than up into the nose - By moving posteriorly against the pharynx, which separates the oropharynx from the nasopharynx, the soft palate acts like a flap valve

hypoglossal nerve lesion

- trauma like a fractured mandible, may injure this nerve, resulting in paralysis and eventual atrophy of one side of the tongue - to clinically test for this the physician will ask the patient to stick out the tongue, if there is a lesion the tongue will deviate toward the same side of the face as the lesion

gag reflex

- when the posterior part of the tongue is touched, the individual gags - CN IX and CN X are responsible for the muscular contraction of each side of the pharynx - glossopharyngeal branches provide the afferent limb of the action

tensor veli palatini muscle

-attaches laterally to the pterygoid plate of the sphenoid bone, hooks around the hamulus, and inserts into the soft palate -innervated by CN V3 - contraction results in tensing of the soft palate, through a pulley mechanism - affects the opening of the auditory tube, acting together with levator veli palatini to open the tube and equalize pressure in the middle ear (popping the eardrum)

sphenopalatine artery

-branch of maxillary artery -passes through incisive canal and foramen behind incisors -supplies anterior part of hard palate -anastomoses with greater palatine artery

nasopalatine nerve

-branch of maxillary nerve CN V2 -enters nasal cavity from pterygopalatine fossa via sphenopalatine foramen -descends obliquely down nasal septum accompanied by sphenopalatine artery -passes through incisive canal and foramen behind incisors -supplies anterior 1/3 of hard palate -anastomoses with greater palatine nerve

geniohyoid

-originates on the anterior body of the mandible - attaches to the hyoid bone - innervated by the nerve to geniohyoid C1-C2

internal laryngeal nerve CN X

-provides somatic motor innervation to the palatoglossus muscle - branch of the vagus nerve - provides general sensation and taste to the epiglottic region of the tongue

geniculate ganglion

-when the chorda tympani joins the lingual nerve in the infratemporal fossa, then taste fibers remain associated with the lingual nerve, they do not leave the lingual nerve to synapse in the this ganglion, which is located in the middle ear