Oral Cavity and Tongue Anatomy PDF

ORAL CAVITY AND THE TONGUE Presented by: ORAL CAVITY Location: Between lips/cheeks (external) and palatoglossal fold (internal). Functions: Mastication, tasting, talking. DIVISIONS OF ORAL CAVITY: Vestibule: Space between teeth and lips/cheeks. Oral Cavity Proper:...

ORAL CAVITY AND THE TONGUE Presented by: ORAL CAVITY Location: Between lips/cheeks (external) and palatoglossal fold (internal). Functions: Mastication, tasting, talking. DIVISIONS OF ORAL CAVITY: Vestibule: Space between teeth and lips/cheeks. Oral Cavity Proper: Internal to the teeth; connects to oropharynx. KEY STRUCTURES: Boundaries: Hard and Soft Palate. Floor: Tongue (major structure) Salivary Glands: Major: Parotid, submandibular, sublingual. Minor: Lingual, palatal, buccal, labial. Muscles: Mouth, cheeks, tongue, soft palate. WALDEYER’S RING (Lymphatic Tissue: EXTERNAL ANATOMY Location: Between lips/cheeks (external) and palatoglossal fold (internal). Functions: Mastication, tasting, talking. LIPS The lips are two soft, fleshy folds that surround the opening of the mouth. 1. Outer Covering: The lips are covered by skin on the outside. 2. Inner lining: Inside, they are lined with a moist layer called the mucous membrane.  Divided into: Upper and a Lower lip it surrounds the opening of the oral cavity Main function: It covers the orbicularis oris muscle, which regulates what comes in and goes out of the mouth. (Oral Anatomy SAS 2 reference) Additional functions: (Online references) - Grasp, hold, and direct food or liquids into the mouth. - Aid in sound articulation and convey emotions through expressions. Both lips have a muscular “skeleton” composed of the orbicularis oris m. Upper lip - separated from the cheek by the nasolabial groove. Lower lip - separated from the chin by the labiomental groove. Upper and lower lips meet at the labial commissures. Vermilion zone—the red area of the lip that At the vermilion border: It is clearly demarcated from the skin of the face Lined by/Covered with: A thinly keratinized layer of stratified squamous epithelium which changes upon transition to the mucous membrane of the oral cavity; also known as “the red zone”. Philtrum—the depressed area Location: Between the base of the nose and the vermilion border of the upper lip CHEEKS Location: Between the labial commissure and the mucosa overlying the ramus of the mandible It has a muscular “skeleton” composed of the buccinator m. Function: (Additional note) Keep food between the teeth and guide it for swallowing. Shield internal structures like teeth and gums. Many mucus-secreting glands known as “buccal glands” Location: within the submucosal layer of the inside of the cheeks Retromolar Triangle Lined by/ Covered with: Mucous membrane of the oral cavity (nonkeratinized stratified squamous epithelium) Vestibule Continues: from the region between the lips and teeth posteriorly, To be located: between the cheek and the teeth The Retromolar Region - the only area in which the vestibule and the oral cavity proper communicate. Parotid duct Drains: into the oral cavity at the parotid papilla Location: along the mucous membrane of the cheek opposite the 2nd maxillary molar Fordyce spots, ectopic sebaceous glands Location: in the mucosa of the cheeks Appearance: Yellowish spots, can be observed in the cheek Vestibule The space between the lips/cheeks and the teeth. Vestibular Fold The tissue fold created by the vestibule between the lips and teeth. Labial Frenula Bands of tissue within the vestibular fold. Pronounced Frenula Found at the maxillary and mandibular midline, forming the upper and lower frenula. Accessory Frenula Smaller bands located in other areas of the vestibule. ORAL CAVITY  The oral cavity, or the mouth, is the space that starts at the lips and goes back to where the throat (pharynx begins). It has two main parts: 1. The Vestibule - the space between the lips, cheeks, and teeth. 2. The oral cavity proper - the larger area inside the teeth, where the tongue is found. At the back of the oral cavity, there are two folds called the palatoglossal folds. These form a boundary called the oropharyngeal isthmus, which is like a doorway leading to the throat.  ORAL CAVITY SENSORY INNERVATION EXTERNAL ANATOMY MUSCLES BOUNDARIES OF THE ORAL CAVITY GENERAL INFORMATION: SUPERIOR BORDER: HARD PALATE The superior border (or roof) of the oral cavity is the hard palate, comprising the anterior 2/3 of the entire palate. Separates the oral cavity from the nasal cavity. Composed of: palatal process of the maxilla & horizontal process of the palatine. SUPERIOR BORDER: HARD PALATE The bones of the hard palate are covered by a thick mucous membrane, known as masticatory mucosa (keratinized stratified squamous epithelium ) · The mucous membrane has a small elevation in the anterior midline called the incisive papilla. SUPERIOR BORDER: HARD PALATE Mucous Membrane The mucous membrane in the anterior region is tightly attached to the underlying palatal process of the maxilla. It is frequently avulsed from the palatal process of the maxilla during the administration of a Nasopalatine nerve block. Moving posteriorly from the incisive papilla, the mucous membrane has a thick midline palatal raphe. Lateral transverse ridges are called transverse rugae (plicae) Deep to the mucous membrane of the hard palate are numerous mucus-secreting glands called palatal (palatine) glands POSTEROSUPERIOR BORDER: SOFT PALATE The soft palate makes up 1/3 of the entire palate. The soft palate separates the oral cavity from the oropharynx. The soft palate has 3 margins: Anteriorly: continuous with the hard palate. Posterolaterally: forms the superior portion of the palatoglossal and palatopharyngeal folds. Posteriorly: the uvula hangs in the center. POSTEROSUPERIOR BORDER: SOFT PALATE The thick palatine aponeurosis forms the foundation of the soft palate. Soft palate is composed of 5 muscles: -Musculus uvulae -Tensor veli palatini -Levator veli palatini -Palatopharyngeus -Palatoglossus (sometimes considered in the grouping of tongue muscles) The soft palate helps close off the nasopharynx during deglutition by forming a seal at the fold of Passavant. LATERAL BORDER: CHEEK The lateral border of the oral cavity extends from the labial commissure (front) to the ramus of the mandible (back). The superior limit of the cheek is the maxillary vestibule, while the inferior limit is the mandibular vestibule. Fordyce spots: Ectopic sebaceous glands found on the inner surface of the cheek. Parotid papilla: Located in the cheek opposite the maxillary second molar. Pterygomandibular raphe: Found in the posterior cheek, serving as a landmark for accessing the pterygomandibular space during inferior alveolar nerve blocks. INFERIOR BORDER: FLOOR OF THE ORAL CAVITY The inferior border is the floor of the oral cavity. Location: along the lingual border of the m andible forming a horseshoe-shaped region. The mylohyoid m. serves as the sling of the oor of the oral cavity and structures superior to it are the major contents The largest structure is the tongue and related musculature TEETH  TEETH The teeth are placed in the alveolar margin of the maxilla and mandible. Each tooth occupies its own socket and is anchored by periodontal ligaments.  TEETH Four Types of Teeth Incisors, Canines, Premolars, and Molars. Humans have 2 sets of teeth during a lifetime: Deciduos Teeth (Primary Dentition or Baby Teeth) are the first set of teeth that emerge in children, typically between six months and three years of age. the 20 deciduos teeth are 4 incisors, 2 canines, and 4 molars in each jaw Permanent Teeth Permanent teeth replace deciduous teeth, usually starting around age six and continuing into early adulthood, resulting in a total of 32 teeth. the 32 permanent teeth are 4 incisors, 2 canines, 4 premolars, and 6 molars in each jaw.  SURFACES OF A TOOTH Labial Surface - The outer surface of the tooth facing the lips in the front teeth. Buccal Surface - The outer surface of the tooth facing the cheeks in the back teeth. Lingual Surface - The inner surface of the tooth facing the tongue. Mesial Surface - The surface of the tooth facing towards the midline of the dental arch. Distal Surface - The surface of the tooth facing away from the midline of the dental arch. Occlusal Surface - The chewing surface of the back teeth where biting occurs. Incisal Edge - The sharp edge of the front teeth used for cutting. BASIC ANATOMY OF A TOOTH BASIC ANATOMY OF A TOOTH BASIC ANATOMY OF A TOOTH  VASCULAR SUPPLY OF THE ORAL CAVITY ARTERIAL SUPPLY OF THE ORAL CAVITY The following supplies the oral cavity, Except:‌ The oral cavity and its Facial Artery‌ components receive the blood supply from the facial, the Lingual Artery‌ lingual, and the maxillary External Carotid branches of the external carotid Artery‌ artery. AOTA‌ Loading...‌  ARTERIAL SUPPLY OF THE PALATE MAXILLARY ARTERY Source: External Carotid Artery Give rise to Sphenopalatine, Greater Palatine, and Lesser Palatine to supply the Palate. Give rise to Ant, Middle, and Pos. Superior Alveolar to supply the Maxillary Arch. Give rise ti Inferior Alveolar to supply the Mandibular Arch.  ARTERIAL SUPPLY OF THE PALATE FACIAL ARTERY Source: External Carotid Artery Arises in the carotid triangle of the neck. Passes superiorly deep to the pos. belly of the digastric m. and the stylohyoid m. Passes along the submandibular gland, giving rise to the submental a., which helps supply the gland. Passes superiorly of the mandible at the masseter  ARTERIAL SUPPLY OF THE FLOOR OF THE ORAL CAVITY FACIAL ARTERY Source: External Carotid Artery Arises in the carotid triangle of the neck. Passes superiorly deep to the pos. belly of the digastric m. and the stylohyoid m. Passes along the submandibular gland, giving rise to the submental a., which helps supply the gland. Passes superiorly of the mandible at the masseter  ARTERIAL SUPPLY OF THE FLOOR OF THE ORAL CAVITY LINGUAL ARTERY Source: External Carotid Artery Passes superiorly and medially toward the hyoid bone. Curves inferiorly and anteriorly, forming a loop that lies on the middle constrictor m. and is passed supercially by the hypoglossal n. Passes deep to the posterior belly of the digastric m. and the stylohyoid m., traveling anteriorly Passes deep to the hyoglossus m. and ascends along the tongue Gives rise to dorsal lingual branches, a sublingual branch, and the deep lingual branch ARTERIAL SUPPLY OF THE FLOOR OF THE MX AND MN TEETH ARTERIAL SUPPLY OF THE FLOOR OF THE MX AND MN TEETH VENOUS DRAINAGE OF THE PALATE ANS FLOOR OF OC Venous Drainage of the Teeth NERVE SUPPLY OF THE ORAL CAVITY The oral cavity receives its sensory innervation from branches of the maxillary and mandibular divisions of the trigeminal nerve.  MAXILLARY NERVE Source: Trigeminal Nerve Sensory in function. Travels along the lateral wall of the cavernous sinus Passes from the middle cranial fossa into the pterygopalatine fossa via the foramen rotundum Within the pterygopalatine fossa, it gives rise to 4 branches: Infraorbital, Ganglionic, Posterior superior alveolar and Zygomatic. The infraorbital n. gives rise to 2 branches that form a plexus with the posterior superior alveolar to supply the maxillary arch: Anterior superior alveolar and Middle superior alveolar  MANDIBULAR NERVE Source: Trigeminal Nerve Motor function in addition to sensory function. The largest of the 3 divisions of the trigeminal n. Created by a large sensory and a small motor root that unite just after passing through the foramen ovale to enter the infratemporal fossa Immediately gives rise to a meningeal branch and divides into an anterior and a posterior division MAXILLARY NERVE Source: Trigeminal Nerve Sensory in function. Travels along the lateral wall of the cavernous sinus Passes from the middle cranial fossa into the pterygopalatine fossa via the foramen rotundum Within the pterygopalatine fossa, it gives rise to 4 branches: Infraorbital, Ganglionic, Posterior superior alveolar and Zygomatic. The infraorbital n. gives rise to 2 branches that form a plexus with the posterior superior alveolar to supply the maxillary arch: Anterior superior alveolar and Middle superior alveolar OVERVIEW AND TOPOGRAPHIC ANATOMY SALIVARY GLANDS  Saliva - is mucous or serous in consistency. 3 pairs of major salivary glands: Parotid gland Submandibular gland Sublingual gland They secrete saliva into the oral cavity to aid in the digestion, mastication, and deglutition of food. Numerous minor salivary glands are ubiquitously distributed throughout the oral mucosa of the oral cavity. TONGUE THE TONGUE Structure: A mass of striated muscle covered with a mucous membrane. Attachments: Superior: Styloid process and soft palate. Inferior: Mandible and hyoid bone. Division: A median fibrous septum divides the tongue into right and left halves. THE TONGUE Landmarks Sulcus Terminalis: V-shaped groove, separates oral and pharyngeal parts. Foramen Cecum: Site of initial thyroid development, at the V's tip. Median Fibrous Septum: Divides tongue into two halves. Functions Mastication Taste Talking Deglutition Muscle Types Extrinsic: Move the tongue as a structure. Intrinsic: Change the tongue's shape. TONGUE MUSCLES Two Groups of Skeletal Innervation: Muscles: Hypoglossal Nerve (CN XII): Intrinsic Muscles: Supplies all tongue Confined to the tongue. muscles except the Not attached to bone. palatoglossus. Extrinsic Muscles: Palatoglossus Muscle: Originate outside the Supplied by vagus tongue. fibers in the pharyngeal Attach to bones and the plexus. soft palate. TONGUE MOVEMENTS Protrusion: Genioglossus muscles on both sides acting together Retraction: Styloglossus and hyoglossus muscles on both sides acting together Depression: Hyoglossus muscles on both sides acting together Retraction and elevation of the posterior third: Styloglossus and palatoglossus muscles on both sides acting together Shape changes: Intrinsic muscles BLOOD SUPPLY The lingual artery, the tonsillar branch of the facial artery, and the ascending pharyngeal artery supply the tongue. The veins drain into the internal jugular vein. LYMPH DRAINAGE Tip: Submental lymph nodes Sides of the anterior two thirds: Submandibular and deep cervical lymph nodes Posterior third: Deep cervical lymph nodes SENSORY INNERVATION Anterior two thirds: Lingual nerve branch of the mandibular division of trigeminal nerve (general sensation) and chorda tympani branch of the facial nerve (taste) Posterior third: Glossopharyngeal nerve (general sensation and taste) GROSS ANATOMY ORAL PART (PRESULCAL) Oral part (anterior 2/3): Movable section of the tongue. Development: From 2 lateral lingual swellings and tuberculum impar (1st pharyngeal arch). Innervation: Trigeminal nerve (lingual branch). Surfaces: Dorsal (top) and ventral (bottom). DORSAL SURFACE Covered by keratinized stratified squamous epithelium. Boundary: Posteriorly marked by the sulcus terminalis. STRUCTURE COMMENTS Median Sulcus Groove in midline; represents the median septum location Papillae (4 types) Papillae: Raised projections that increase surface area. 1. Filiform: Most numerous, no taste buds 2. Fungiform: Taste buds, Taste types: Bitter, salt, sweet, sour, and umami, detected by taste buds. non-keratinized 3. Foliate: Taste buds, non- keratinized, on sides 4. Circumvallate: Taste buds, near sulcus terminalis Glands Numerous mucous and serous glands on dorsal surface VENTRAL SURFACE The mucosa is nonkeratinized strati ed squamous epithelium STRUCTURE COMMENTS Lingual frenulum Fold connecting ventral tongue surface to oral cavity floor Sublingual papilla Saliva entry point from submandibular glands Plica mbriata Fimbriated folds lateral to lingual frenulum Deep lingual veins Visible through mucosa between plica fimbriata and lingual frenulum PHARYNGEAL PART (POSTSULCAL Posterior 1/3 of the tongue. Development: From the hypobranchial eminence of the 3rd pharyngeal arch; mucosa innervated by the glossopharyngeal nerve. Location: Begins posterior to the palatoglossal folds (anterior pillar of the fauces) in the oropharynx. Surface: Only has a dorsal surface. Papilla: Absent. DORSAL SURFACE The mucosa is nonkeratinized strati ed squamous epithelium STRUCTURE COMMENTS Lingual tonsils Lymphatic tissue covering pharyngeal surface Glossoepiglottic folds Mucosa connecting tongue and epiglottis; includes median and lateral folds MUSCLES EXTRINSIC TONGUE MUSCLES: MUSCLE ORIGIN INSERTION ACTION NERVE Superior genial Genioglossus Entire tongue, hyoid Protrusion, Hypoglossal n. tubercle Passive depression, deviation Hyoglossus Lateral tongue Depression Hypoglossal n. Hyoid bone Styloglossus Lateral tongue Retrusion, elevation Hypoglossal n. Styloid process Elevation of tongue Palatoglossus Palatine aponeurosis Lateral tongue Pharyngeal plexus root INTRINSIC TONGUE MUSCLES: MUSCLE ACTION NERVE Superior Shortens, curls apex upward Longitudinal Hypoglossal n. Inferior Shortens, curls apex Longitudinal Hypoglossal n. downward Transverse Hypoglossal n. Narrows, lengthens Vertical Broadens, flattens Hypoglossal n. NERVE SUPPLY SENSORY INNERVATION: Types of Sensory Nerve Supply General somatic afferent (GSA) Function: Pain, temperature, discriminative touch. Nerves: Trigeminal (via lingual), glossopharyngeal, vagus (via internal laryngeal); innervates mucosa. Special visceral afferent (SVA) Function: Taste. Nerves: Facial (via chorda tympani), glossopharyngeal, vagus (via internal laryngeal); innervates taste buds.  GENERAL SENSORY INNERVATION (GENERAL SOMATIC AFFERENT) NERVE SOURCE COURSE DISTRIBUTION Mandibular division of Passes near lateral pterygoid, joins Anterior 2/3 tongue, Lingual trigeminal chorda tympani, enters oral cavity oral floor mucosa, and near hyoglossus and mandibular gingiva. submandibular duct. Cranial nerve from Passes through jugular foramen, Posterior 1/3 tongue Glossopharyngeal travels with stylopharyngeus, and medulla and fauces. reaches the palatine tonsils. Passes through jugular foramen, Base of tongue, Internal Superior laryngeal travels with superior laryngeal n., epiglottis, and larynx laryngeal branch of vagus and enters larynx through mucosa to false cords. thyrohyoid membrane.  SPECIAL SENSORY INNERVATION (SPECIAL VISCERAL AFFERENT) NERVE SOURCE COURSE DISTRIBUTION Passes through tympanic cavity, Taste buds on anterior Facial n. in tympanic exits petrotympanic fissure, joins Chorda tympani 2/3 tongue. cavity lingual n., and reaches anterior 2/3 tongue. Cranial nerve from Passes through jugular foramen, Taste buds on posterior Glossopharyngeal travels with stylopharyngeus, and 1/3 tongue and medulla circumvallate papilla. reaches the palatine tonsils. Passes through jugular foramen, Taste buds at tongue Internal Superior laryngeal travels with superior laryngeal n., base and epiglottis. laryngeal branch of vagus and enters larynx through thyrohyoid membrane.  MOTOR INNERVATION NERVE SOURCE COURSE DISTRIBUTION Passes through hypoglossal canal, All intrinsic tongue Rootlets from medulla travels with internal carotid a., Hypoglossal muscles, hyoglossus, oblongata jugular v., and occipital a., and styloglossus, and runs deep to muscles like genioglossus. mylohyoid and genioglossus. Pharyngeal plexus Forms along the middle constrictor m. and distributes motor branches Palatoglossus and Pharyngeal branch of muscles of the pharynx vagus n. to pharyngeal and soft palate and soft palate. muscles (except tensor veli palatini). VASCULAR SUPPLY  - the terminal branch of the lingual artery after the sublingual branch is Deep lingual artery given off, travels superiorly to the tongue's ventral surface. -Runs between the inferior longitudinal muscle of the tongue and the mucous membrane. -This artery is accompanied by branches of the lingual nerve and anastomoses with its counterpart on the opposite side to provide continuous blood supply.  - the terminal branch of the lingual artery after the sublingual branch is Deep lingual artery given off, travels superiorly to the tongue's ventral surface. -Runs between the inferior longitudinal muscle of the tongue and the mucous membrane. -This artery is accompanied by branches of the lingual nerve and anastomoses with its counterpart on the opposite side to provide continuous blood supply.