Dental Anatomy, Embryology, and Histology Units 16-20 Exam 3, Exams of Dental Anatomy

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Dental Anatomy, Embryology, and

Histology Units 16-20 Exam 3

Function of the cardiovascular system -Respiration: transports oxygen -Nutritive: supplies nutrients -Excretory: carries away waste products and carbon dioxide Two major arteries that supply the head and neck -Common carotid: right and left -Subclavian: right and left Left side of the body Common carotid and subclavian arise directly from aorta Right side of the body -Common carotid and subclavian are both branches from the brachiocephalic artery -The brachiocephalic is a direct branch of the aorta Is the brachiocephalic artery only on the right side? Yes The common carotid branches off to the internal carotid artery. What does it supply? -Intracranial structures and is the source for the ophthalmic artery -Supplies eyes and the brain. NOT THE MOUTH The common carotid branches off to the external carotid artery. What does it supply? -Extracranial structures of the head and neck including the oral cavity Venous drainage of the heart general information -Veins usually travel with arteries with similar names -Superficial and deep veins

-Usually no valves, potential danger to brain due to infection Facial vein Several branches -Nose, lips, eyes, submental, and submandibular regions -Drains into the internal jugular vein Superficial temporal vein -Superficially located -Drains lateral scalp Maxillary vein -Deeper located compared to the superficial temporal vein -Drains into and forms the retromandibular vein Retromandibular vein -The superficial temporal vein joins the maxillary vein to form the retromandibular vein -Anterior division: joins facial vein -Posterior division: become the external jugular vein Pterygoid plexus of veins -Collection of veins that drain the following structures: muscles of mastication, buccinator muscle, nose, palate, and teeth -Maxillary vein drains the plexus -Proximity to the maxillary tuberosity and significance Thrombus Clot that forms in the inner vessel wall Embolus -Thrombus that may dislodge from the inner vessel wall and travel -Can cause a TIA

Bacteremia Bacteria that travels in the blood Hemorrhage Blood vessel that is injured; large amounts of blood escape into surrounding tissues without clotting Hematoma -Bruise -Localized blood vessel trauma; blood vessel injured and a small amount of blood escapes into surrounding tissue then clots -A hematoma does not cause blood clots Anterior branches of the external carotid artery -Superior thyroid (don't need to know) -Lingual artery (3 branches) -Facial artery (6 branches) Lingual artery branches -Dorsal lingual -Deep lingual -Sublingual Facial artery -Location of facial artery: arises slightly superior the the lingual artery as it branches off anteriorly. Runs medial to the mandible, over sub man. salivary gland, then around mandibles lower border to its lateral side. -Area it supplies: 6 branches Facial artery branches Submental -Location: it arises below the mandible and runs toward the chin

-Area it supplies: submandibular lymph nodes, submandibular salivary gland, mylohyoid muscle, and anterior belly of the digastric muscle Inferior labial -Location: it runs below the mouth, deep to the orbicularis oris -Area it supplies: lower lip tissues, including muscles of facial expression Superior labial -Location: runs above the mouth -Area it supplies: upper lip tissues Facial artery branches continued... Lateral nasal -Location: runs along side of the nose -Area it supplies: skin and muscles of the nose Angular -Location: it is the terminal branch of the facial artery -Area it supplies: tissues along the side of the nose Posterior branches of the external carotid artery -Occipital -Posterior auricular Occipital Location -Arises from the external carotid as it passes upward behind the ascending ramus of the mandible, and travels to the posterior portion of the scalp Area it supplies -Suprahyoid and sternocleidomastoid muscles, as well as the scalp and meningeal tissues in the occipital region Posterior auricular Location

-Arises superior to the occipital artery and stylohyoid muscle about the level of the tip of the styloid process Area it supplies -Internal ear by its auricular branch and the mastoid air cells by the stylomastoid artery Terminal branches of the external carotid artery -Superficial temporal (smaller terminal branch of the external carotid artery) (4 branches) -Maxillary (larger terminal branch of the external carotid artery) (10 branches) Superficial temporal artery branches -Transverse facial -Middle temporal -Frontal branch -Parietal branch Maxillary artery Location -Begins in the neck of the mandibular condyle within the parotid gland. The artery runs through the infratemporal fossa. After traversing the infratemporal fossa, the artery enters the pterygopalatine fossa (behind and below the eye) Area it supplies -The 10 branches Maxillary artery branches -Middle meningeal (don't need to know) -Inferior alveolar (IA) (3 branches) -Deep temporal arteries (don't need to know) -Pterygoid arteries -Masseteric -Buccal

-Posterior superior alveolar (PSA) -Infraorbital (1 branch) -Descending palatine (2 branches) -Sphenopalatine (3 branches) Maxillary artery branches Inferior alveolar (IA) Inferior alveolar (IA) (3 branches) -Location: arises from the maxillary artery in the infratemporal fossa. The artery runs inferiorly to enter the mandibular foramen and then the mandibular canal -Area it supplies: Dental branches- pulp tissue of the mandibular posterior teeth. Alveolar branches- periodontium of the mandibular posterior teeth including facial gingiva The 3 branches of the inferior alveolar Mylohyoid Location: arises from the inferior alveolar artery before the main artery enters the mandibular canal by way of the mandibular foramen. It travels in the mylohyoid groove Area it supplies: floor of mouth and mylohyoid muscle Mental Location: arises from the inferior alveolar artery and exits the mandibular canal by way of the mental foramen Area it supplies: soft tissue of the chin and anastomoses with the inferior labial artery Incisive Location: branches off the inferior alveolar artery and remains in the mandibular canal to divide into alveolar and dental branches Area it supplies: Dental branches- pulp tissue of mandibular anterior teeth. Alveolar branches- periodontium of the mandibular anterior teeth including the facial gingiva Pterygoid arteries Location -Near lateral and medial pterygoid muscles Area it supplies

-Lateral and medial pterygoid muscles Masseteric Location -Located near masseter muscle Area is supplies -Masseter muscle Buccal Location -Located near the buccinator muscle Area it supplies -Buccinator muscle and other soft tissues of the cheek Posterior superior alveolar (PSA) Location -Artery enters the posterior superior alveolar foramina on the maxillary tuberosity and gives off dental and alveolar branches. This artery also anastomoses with the anterior superior alveolar artery Area it supplies -Dental branches: pulp tissue of posterior maxillary teeth. Alveolar branches: periodontium of the posterior maxillary teeth including facial gingiva Infraorbital Location -Branches from the maxillary artery in the pterygopalatine fossa and may share a common trunk with the PSA. The artery enters the orbit through the inferior orbital fissure and travels in the infraorbital canal. Finally, the artery emerges through the infraorbital foramen Area it supples -Infraorbital region of the face

Infraorbital branch: anterior superior alveolar (ASA) Anterior superior alveolar (ASA) (anastomoses with the posterior superior alveolar artery) -Location: arises from the infraorbital artery and gives off dental and alveolar branches. The ASA also anastomoses with the PSA -Area it supplies: Dental branches- pulp tissue of the anterior maxillary teeth. Alveolar branches- periodontium of the anterior maxillary teeth including facial gingiva Middle superior alveolar artery MSA NOT ALWAYS PRESENT -Area it supplies: maxillary premolars and the mesial portion of the maxillary first molars (mb root and mb cusp) and facial gingiva Descending palatine Location -Descending through the pterygopalatine fossa and then through the pterygopalatine canal Area it supplies -2 branches: greater palatine and lesser palatine Descending palatine branches Greater palatine and Lesser palatine Greater palatine (GP) -Location: emerges from the greater palatine foramen -Area it supplies: maxillary posterior lingual gingiva, palatine glands, posterior hard palate Lesser palatine -Location: emerges from the lesser palatine foramen -Area it supples: tonsils and soft palate Sphenopalatine 3 branches (only need to know nasopalatine) -Posterior lateral nasal artery -Posterior sepal artery -Nasopalatine artery (NP) Location: travels through the incisive foramen and anastomoses with the greater palatine foramen

Area it supplies: anterior hard plate, lingual gingiva of the maxillary anterior teeth as well as nasal septal tissue Salivary gland tissue develops From the epithelium that lines the early oral cavity Are salivary glands endocrine glands or exocrine glands? Exocrine Sizes of salivary glands -Minor: short ducts -Major: large ducts (3 paired glands) Secretions of salivary glands -Serous: very thin, water secretions, amylase (an enzyme in the saliva that helps to break down carbohydrates) -Mucous: thick, sticky, viscous, mucin (secrets mucous in glands) function is to lubricate -Mixed: both serous and mucous Function of salivary glands -Minor: secrete minor amounts of saliva to keep the mucosa moist (lubricate) -Major: produces saliva to mix with food to initiate the digestive process Saliva due to its liquid state (chemical composition) -Assists in mastication of food -Serves as a solvent -Contributes to digestion of carbohydrates -Lubricates food and oral tissues -Acts as a buffer protecting oral mucosa against acids from food and plaque -Cleanses mouth by flushing out debris -Acts to inhibit growth of some bacteria -Tissue repair (bleeding time of oral tissues is shorter due to saliva mixed with blood resulting in clotting

Parotid (major salivary gland) -Location: side of the face; anterior and inferior to the ear Pertinent info: -Encapsulated gland -Largest gland with a long duct -25% TRSV (total resting salivary volume) -Secrets serous via Stensons duct (parotid duct) -Associated with Mumps Submandibular (major salivary gland) -Location: medial surface of mandible in the submandibular fossa; behind and lower to to the location of the sublingual salivary gland Pertinent info: -2nd largest, encapsulated gland -Size of a walnut -80% serous, 20% mucous= mixed -Duct arises from the deep lobe -Functions in lubrication and digestion of food -Wharton's duct (submandibular duct) opens at sublingual caruncle -60%-65% of TRSV Sublingual (major salivary gland) -Location: anterior to submandibular gland; in sublingual fossa; superior to mylohyoid muscle Pertinent info: -Un-encapsulated gland -Smallest of the major salivary glands -10% TRSV mixed gland but mostly mucous

-Bartholin's duct (sublingual duct) opens at sublingual caruncle -Other small ducts open along sublingual fold (ducts of Rivinus) -Palpate with one hand intraorally and one hand extraorally Minor salivary glands 600-1000 salivary glands Less than 10% TRSV Labial (minor salivary gland) -Location: found in submucosa of lips; numerous at the midline; open directly into lip mucosa -Secretion: mixed; primarily mucous Buccal (minor salivary gland) -Location: located on the inner cheek region -Secretion: mostly mucous Palatine (minor salivary gland) -Location: on soft palate plus posterior lateral borders on hard palate; not on anterior hard palate (the tissue is more keratinized) -Secretion: mucous Lingual (anterior lingual) (minor salivary gland) -Location: apex of tongue (ducts empty on ventral surface of the tongue - known as Blandin and Nuhn) -Secretion: mainly mucous Lingual glands of Von Ebner (minor salivary gland) -Location: beneath circumvallate papillae; ducts open into trough of the papillae -Secretion: purely serous Posterior lingual (minor salivary gland) -Location: near lingual tonsils on posterior third of tongue

-Secretion: purely mucous Sialolith -Salivary stone -Blocked duct (hard and calcified) -Submandibular gland most often involved due to treacherous haul up duct Mucocele -Saliva-filled sac -Often bluish in color -Blocked minor duct Ranula -Lesion that results from retention of saliva -Looks like a frog -Involves mostly submandibular gland Xerostomia -Dry mouth; lower salivary flow -Seen in diabetics, certain meds (anti-depressants) -Has significant effect on oral tissues Sialorrhea -Overproduction of saliva -Teething or mental retardation Function of lymphatic system Filtering out waste products and helps to fight diseases (part of the immune system) What does the lymphatic system consist of? -Lymphatic vessels -Lymphatic ducts

-Lymph fluid -Lymph nodes -Lymphocytes Lymphatic vessels -Lymph drains from surrounding areas into vessels -Tubules or channels that parallel the venous system -Communicate with other lymph vessels -Pulp of tooth tissue has lymph vessels -One-way valve system Lymphatic ducts -Larger lymphatic vessels that drain smaller vessels, and empty into the venous system Lymph fluid -Known as lymph -Extracellular tissue fluid that eventually empties into the venous system Lymph nodes -Bean shaped bodies consisting of lymphoid tissue and contains lymphocytes -Nodes are connected to lymphatic vessels -Positioned to filter out waste products from lymph to prevent entry into the blood system -Afferent vessels: lymph comes into the node -Hilus: one side of node- depression -Efferent vessel: single, lymph flows out of node Lymphocytes -Lymph cells that are produced within the lymph node -White blood cells that are found in lymph -They actively remove toxic products

-An increase in white blood cells signifies that the body is fighting an infection Classification of lymph nodes Primary nodes (regional nodes) -Lymph from a particular region -Localized Secondary nodes (central nodes) -Lymph node that drains lymph from a primary node -More distant region Tertiary -Third in line -Lymph node that drains lymph from a secondary node Lymph nodes in healthy individuals -Usually small, soft, free in tissue -Superficial or deep -Can't be palpated during extraoral exams because they aren't tender to the touch Lymphadenopathy -Increase in size and change of consistency of lymphoid tissue due to increase in both size and overall count of lymphocytes Changes in lymph nodes during lymphadenopathy -Nodes can be palpated during extraoral/intraoral exam -Nodes can be firm to boney hard; remain free (mobile) from surrounding tissue or can be attached/fixed to tissues such as skin, bone, or muscle -Tender to touch; tenderness is due to pressure on the area nerves from node enlargement Lymph nodes role in metastasis and cancer -Metastasis: spread of cancer or growth from primary site to secondary site, etc...

-Nodes can become involved in process; if the various lymph nodes don't stop the cancer, it will progress to the lymphatic ducts, and on to the venous system Tonsils (masses of lymphoid tissue) Palatine -Two rounded masses in the oral cavity between the anterior and posterior tonsillar pillar Lingual -A layer of lymphoid tissue located on the base of the dorsal surface of the tongue Pharyngeal -Located on the posterior wall of the nasopharynx; AKA adenoids Tubal -In the nasopharynx, posterior to the eustachian tubes Lymph node distribution patterns Submental nodes -Mandibular incisors 23-26, tip of the tongue, and midline of the lower lip and chin drain into these nodes -Sequence: submental nodes (primary), submandibular nodes (secondary), and cervical nodes (tertiary) Lymph node distribution patterns Submandibular nodes -Maxillary teeth 2-15 (except maxillary third molars 1 and 16), maxillary sinuses, mandibular canines 22 and 27, and all mandibular posterior teeth 17-21 and 28-32, floor of mouth, body of tongue, cheek area, hard palate, and the anterior nasal cavity drain into these nodes -Sequence: submandibular nodes (primary). cervical (secondary) Lymph node distribution patterns Upper deep cervical nodes (cervical) -Third molar regions 1 and 16 and 17 and 32, base of tongue, tonsillar area, soft palate, and the posterior nasal cavity region drain into these nodes -Sequence: upper deep cervical nodes (primary), cervical nodes (secondary) Lymph node distribution patterns Lower deep cervical nodes -Back of the neck, and glands in the anterior neck region drain into these nodes

-Sequence: lower deep cervical nodes (primary), junction of the subclavian and internal jugular veins (secondary) Digital palpation -Use of a single finger to examine tissues Bidigital palpation -One or more fingers and thumb to examine tissues by grasping and rolling tissue between thumb and finger Manual palpation -Use of all fingers of one hand to examine tissues Bimanual palpation -Use of both hands by grasping tissue between them for examination Bilateral palpation -Examination of structures on both sides of the face and neck simultaneously to detect differences between sides Circular compressions palpation -Moving fingertips in a circular pattern over a structure while simultaneously applying pressure to the tissue Function of the nervous system -Causes muscles to contract (important for mastication and speech) -Stimulates glands to secrete -Helps with sensations that can be perceived (such as pain and touch) Neuron (nerve cell) has three parts Cell body -Core of neuron -Contains the nucleus Dendrite -Process that conducts impulses toward a cell body

-May have 1 or many dendrites Axon -Process that carries impulses away from the cell body -Usually only 1 axon Two parts of the nervous system Central Nervous System (CNS) Consists of -Spinal cord: contained in the vertebral column -Brain: housed within the skull Two parts of the nervous system Peripheral Nervous System (PNS) -Made up of nerves that travel away from CNS Consists of -12 pairs: cranial nerves -31 pairs: spinal nerves -Autonomic nervous system Autonomic Nervous System (ANS) (2 parts) -Consists of efferent (motor nerves) -Operates without conscious control Sympathetic -Response to emergencies (fight or flight) -Increase respiration, heart rate, blood flow to muscles -Decrease salivary flow, and blood supply to digestive tract Parasympathetic -Rest or digest -Decrease heart rate and respiration -Increase salivary flow, blood supply to digestive tract

Cranial nerves that are an important part of the peripheral nervous system (12 pairs) -Afferent (sensory) -Efferent (motor) -Both types: afferent and efferent Nerve lesions of the head and neck Facial Paralysis -Loss of muscle action of facial expression muscles -Can be unilateral or bilateral and can occur secondary to a stroke -Muscles lose tone (drooping of eyes and structures, dripping of saliva) -Can result from incorrectly administering of an IA injection. Injury to parotid gland Nerve lesions of the head and neck Bell's Palsy -Unilateral facial paralysis -No known cause -Onset, abrupt, all or some facial nerve involved -No specific treatment Nerve lesions of the head and neck Trigeminal Neuralgia -No known cause -Cranial nerve V is involved -Theory is that the lesion is caused by pressure on the sensory root of the trigeminal gangilion by area of blood pressure -Patient feels extreme pain -Treatment may include peripheral neurectomy (cutting off innervation of the affected tissues) What is the smallest cranial nerve? -Trochlear nerve (IV) Trigeminal Nerve (V) (largest cranial nerve) Function: only sensory

-Ophthalmic branch (V1) to cornea, ciliary body, conjunctiva, iris, lacrimal gland, nasal mucosa, eyelid, eyebrow, forehead, nose, ethmoid and frontal sinuses, plus a portion of the dura mater -Exit site for V1: superior orbital fissure Function: only sensory -Maxillary branch (V2) to skin of cheek, lower eyelid, nasal cavity, maxilla, and overlying skin, teeth and mucosa, maxillary sinuses, palate, nasopharynx, and portion of the dura mater -Exit site for V2: foramen rotundum Function: both sensory and motor -Mandibular branch (V3) -Sensory: to lower jaw, teeth, and mucosa -Motor: muscles of mastication and other cranial nerves -Exit site for V3: foramen ovale Facial Nerve (VII) Function: both sensory and motor -Motor: muscles of facial expression, stapedius, stylohyoid, and posterior belly of the digastric muscle -Sensory: taste sensation of tongue (anterior 2/3rds); skin around ear; taste sensation in the palate -Parasympathetic: submandibular and sublingual salivary glands, lacrimal, nasal, and palatine glands -Exit site: stylomastoid foramen Glossopharyngeal nerve (IX) Function: both sensory and motor -Sensory: taste buds to posterior 1/3rd of tongue; sensation from fauces, tonsils, pharynx, and soft palate -Motor: muscles of the pharynx -Parasympathetic: parotid gland -Exit site: jugular foramen Vagus nerve (X) (longest cranial nerve) Function: both sensory and motor

-Motor: muscles of the soft palate, pharynx, and larynx -Sensory: skin around the ear; taste sensation of the epiglottis -Parasympathetic: thorax, abdomen, thymus gland, heart, and stomach -Exit site: jugular foramen Spinal accessory nerve (XI) Function: motor -Motor: sternocleidomastoid and trapezius muscles; soft palate and pharynx -Exit site: jugular foramen Hypoglossal nerve (XII) Function: motor -Motor: intrinsic and extrinsic tongue muscles -Exit site: hypoglossal canal Ophthalmic division of the trigeminal nerve (V) (V1) -Entirely afferent/sensory Lacrimal nerve -Innervates the lacrimal glands for tear production, supplies the lateral part of the upper eyelid, and conjunctiva Frontal nerve (two branches) -Supraorbital nerve branch: supplies the skin of the forehead, scalp, and upper eyelid -Supratrochlear: supplies the area from the bridge of the nose, medial parts of the upper eyelid and forehead Nasociliary nerve (three branches) -Infratrochlear nerve branch: supples the skin of the medial part of the eyelids and the side of the nose -Ciliary nerves: supplies innervation to and from the eyeball -Anterior ethmoidal nerve: (formed by external nasal nerve and the internal nasal nerve) supplies the nasal cavity and paranasal sinuses

Maxillary division of the trigeminal nerve (V) (V2) -Entirely afferent/sensory Zygomatic nerve (two branches) -Zygomaticotemporal nerve branch: supplies the skin of the temporal region -Zygomaticofacial nerve branch: supplies skin of cheek Infraorbital nerve (two branches): Supplies the upper lip, medial portion of the cheek, lower eyelid, and the side of the nose -Middle superior alveolar nerve branch MSA (may not always be present)(joins the infraorbital nerve in the infraorbital canal): mesiobuccal root of maxillary first molar, maxillary first and second premolars, buccal gingiva, and maxillary sinus -Anterior superior alveolar nerve branch ASA (joins the infraorbital nerve in the infraorbital canal): supplies maxillary incisors and canine teeth(6-11), facial (labial) gingiva, and maxillary sinus Posterior superior alveolar nerve PSA (joins the infraorbital nerve in the pterygopalatine fossa) -Supplies maxillary molar teeth (with the exception of the mesio-buccal root of the maxillary first molar which is innervated by MSA. Also supplies facial gingiva to maxillary molar teeth plus maxillary sinus Greater palatine nerve GP (enters the greater palatine foramen to travel in the pterygopalatine canal) -Supplies mucosa of the posterior hard palate and the lingual gingiva of the maxillary premolars and molars Nasopalatine nerve NP -Supplies the nasal septal tissues, anterior hard palate, and the lingual gingiva of the maxillary incisors and canines Mandibular division of the trigeminal nerve (V) (V3) -Both afferent and efferent -Anterior division/trunk of mandibular nerve (afferent/sensory branch) Buccal (long buccal) nerve -Supplies skin of cheek, buccal mucous membranes, and buccal gingiva of the mandibular teeth only Anterior division/trunk of mandibular nerve (efferent/motor branch) Masseteric never -Supplies the masseter muscle

Lateral pterygoid nerve -Supples the lateral pterygoid muscle Anterior and posterior deep temporal nerves -Supplies the temporalis muscle Posterior division/trunk of mandibular nerve (afferent/sensory branch) Auriculotemporal nerve -Supplies the skin of the temporal region in front of the ear, the external acoustic meatus, and the TMJ Lingual nerve (joined by the chorda tympani (branch of the facial nerve VII) -Supplies general sensation for the body of the tongue, floor of the mouth, and lingual gingiva of mandibular teeth Inferior alveolar nerve (three branches) (runs parallel with lingual nerve within mandibular canal. Mandibular molar and premolar teeth plus buccal gingiva of premolars) -Mental nerve branch (sensory): supplies the chin, lower lip, and labial mucosa near mandibular anterior teeth -Incisive nerve branch: supplies the mandibular anterior teeth and facial (labial) gingiva -Mylohyoid nerve branch: (efferent/motor branch of posterior division/ trunk of mandibular nerve): supplies sensation to the mylohyoid muscle and the anterior belly of the digastric muscle Facial nerve (VII) Branches -Greater petrosal nerve (pterygopalatine ganglion involved): supplies parasympathetic nerve fibers to the lacrimal, nasal, and palatine glands; plus serves as afferent nerve fibers for taste sensation in the palate -Nerve to stapedius muscle: supplies efferent nerve fibers to the stapedius muscle in the middle ear -Chorda tympani nerve (submandibular ganglion involved): joins with lingual nerve, parasympathetic nerve fibers to the submandibular and sublingual salivary glands plus serves as afferent nerve fibers for taste sensation to the anterior 2/3rds of the tongue Facial nerve enters the parotid gland and supplies additional efferent nerve branches to the muscles of facial expression (temporal, zygomatic, buccal, (marginal) mandibular and cervical branches) The facial nerve does not innervate the parotid gland, but rather travels within it

The parotid gland is innervated by cranial nerve IX Glossopharyneal