T2 L10 - The Neck and Oral Cavity 22-23(3).pptx

Module 202 - Theme 2 - Lecture 10 The Neck and Oral Cavity A riddle while you wait: A hole in the back-most fossa That two nerves, one art, pass through If tumour were to compress it Can’t walk straight, feel face, hear you. Module 202 - Theme 2 - Lecture 10 The Neck and Oral Cavity Dominic O’Br...

Module 202 - Theme 2 - Lecture 10 The Neck and Oral Cavity A riddle while you wait: A hole in the back-most fossa That two nerves, one art, pass through If tumour were to compress it Can’t walk straight, feel face, hear you. Module 202 - Theme 2 - Lecture 10 The Neck and Oral Cavity Dominic O’Brien MSc, FHEA, PGCert Pronouns: he/she/they Lecturer in Anatomy D.O’[email protected] Join at slido.com #2006314 ⓘ Start presenting to display the joining instructions on this slide. Previously on module 202... Which muscle is responsible for lifting the eyelid (X)? A. Levator palpebrae superioris B. Occipitofrontalis C. Orbicularis oculi D. Superior oblique (X ) E. Superior rectus Previously on module 202... Which muscle is responsible for lifting the eyelid (X)? A. Levator palpebrae superioris B. Occipitofrontalis C. Orbicularis oculi D. Superior oblique (X ) E. Superior rectus Previously on module 202... An inferior alveolar nerve block would block sensation from which structure(s)? A. Dura B. External ear C. Mandibular teeth D. Maxillary teeth E. Parotid gland Previously on module 202... An inferior alveolar nerve block would block sensation from which structure(s)? A. Dura B. External ear C. Mandibular teeth D. Maxillary teeth E. Parotid gland Outcomes Gain an overview of the embryological development of the head and neck Explore the anatomy of the mouth Describe the components of the tongue and its innervation from CN V, VII, IX Identify the main structures of the larynx and pharynx Understand the anatomical and functional relations of cranial nerves VIII, IX, X, XI & XII Describe the triangles of the neck and locate the main neurovascular structures that transverse the neck Embryology of the Head and Neck Trilaminar disk - Ectoderm - Mesoderm - Endoderm Pharyngeal arches Anteromedial ‘folding’ Illustrations from Soton Brain Hub Embryology of the Head and Neck Trilaminar disk Pharyngeal arches - 6 in total - 5th arch is underdeveloped, so excluded - Each innervated by different CNs Anteromedial ‘folding’ Illustrations from Soton Brain Hub Embryology of the Head and Neck Clinical relevance: Developmental abnormalities - Cleft palate - Cleft lip Illustrations from Soton Brain Hub Embryology of the Head and Neck Clinical relevance - Cleft palate - Cleft lip - Most common facial birth defect Seen in 1 in 700 births NHS Overview Glossary of Muscle Attachments Genio - Chin Hyo - Hyoid bone Sterno - Sternum Thyro - Thyroid Omo - Scapula Mylo - Mandible Stylo - Styloid process Glosso - Tongue Oral Cavity First part of the digestive system Continuous with the nasal cavity & pharynx Divided into: - Oral vestibule - Inner oral cavity Roof comprises of the hard and soft palate Floor is formed by musculature - Contains submandibular and sublingual salivary glands Oral vestibule The Tongue The tongue is divided into sections: - Oral (anterior two thirds) - Pharyngeal (posterior third) - Transition marked by the terminal sulcus Three types of papillae cover the tongue: - Fungiform - Filiform - The only type without taste buds - Vallate (circumvallate) Under surface contains medial fold (frenulum) which internally separates the right and left sides of the tongue. Muscles of the Tongue Intrinsic - Longitudinal, transverse and vertical - Precision movements for speech, eating and swallowing. Extrinsic - Genioglossus - Depresses and protrudes tongue - Hyoglossus - Depresses tongue - Styloglossus - Retracts tongue - Palatoglossus - Elevates back of tongue and depresses soft palate Innervation of the Tongue Anterior 2/3rd Taste - Facial (CN VII) via Chorda tympani contributing to lingual nerve (V3) Sensation - Lingual nerve (V3) Posterior 1/3rd Taste - Glossopharyngeal (CN IX) Sensation - Glossopharyngeal (CN IX) Motor to whole tongue Hypoglossal nerve (CN XII) - Except palatoglossus (CN X) The Glossopharyngeal Nerve - CN IX Exits via the jugular foramen Sensory innervation Posterior 1/3 tongue, oropharynx Special sensory innervation (Taste) Posterior 1/3 tongue Motor Stylopharyngeus Visceral Parotid gland - stimulates secretion to aid digestion The Hypoglossal Nerve - CN XII Exits via hypoglossal canal Motor innervation Intrinsic and extrinsic muscles of the tongue Injury will cause tongue to deviate towards the side with the lesion Quiz Which cranial nerve provides special sensory innervation to the anterior third of the tongue? A. CN B. CN C. CN D. CN E. CN V VII VIII IX X Quiz Which cranial nerve provides special sensory innervation to the anterior third of the tongue? A. CN B. CN C. CN D. CN E. CN V VII VIII IX X The Larynx Protective sphincter for air passages and produces phonation. Made up of several cartilaginous structures: - Thyroid - Cricoid - Arytenoid - Cuneiform - Corniculate - Epiglottis Cuneiform cartilage Neurovascular supply: - Sensory and motor from: Vagus, via the superior laryngeal branch and recurrent laryngeal branch. - Arterial: superior and inferior thyroid artery The Pharynx Most posterior part of the neck - Situated behind the nasal cavity and the larynx Consists of three sections: - Nasopharynx - Laryngopharynx - Oropharynx Three constrictor muscles - Superior, middle and inferior Innervation: - Motor: Vagus (except stylopharyngeus via CN IX) - Sensory: CN V2, CN IX, CN X The Vagus Nerve - CN X Arises from medulla and exits through the jugular foramen Continues in carotid sheath, branching into head and thorax Innervation Sensory - larynx, dura mater Taste - epiglottis and pharynx Visceral sensory - aortic bodies, aortic arch chemoreceptors, bronchi, heart, lungs, midgut and foregut Motor - palatoglossus, muscles of pharynx and larynx Visceral motor - parasympathetic to smooth muscle in glands in pharynx, larynx, thorax, foregut and midgut. Quiz Injury to the left recurrent laryngeal nerve can occur during cardiac surgery. What is a common sign of this iatrogenic injury? A. Aphonia (Loss of voice) B. Hoarseness of voice C. Hypertension D. Laryngeal bleeding E. Tachycardia Quiz Injury to the left recurrent laryngeal nerve can occur during cardiac surgery. What is a common sign of this iatrogenic injury? A. Aphonia (Loss of voice) B. Hoarseness of voice C. Hypertension D. Laryngeal bleeding E. Tachycardia The Neck Transition between base of cranium and the thoracic cage Supported by 7 cervical vertebrae - Atlas - Axis - C3 - C7 - C3 - C6 are “typical” Contains the Hyoid bone Fascial Layers in the Neck Three layers: - Pretracheal fascia - Prevertebral fascia - Investing fascia Reduces the spread of infection Enables structures to move past each other in movement and swallowing Carotid sheath contains: - Common and internal carotid arteries - Internal jugular vein - Vagus nerve (CN X) - Deep cervical lymph nodes - Carotid sinus nerve Surface Anatomy of the Neck Divided into the anterior and posterior compartment by sternocleidomastoid Anterior compartment subdivided into: - Submental triangle - Submandibular triangles - Carotid triangles - Muscular triangles Posterior compartment subdivided into: - Occipital triangles - Omoclavicular triangles - Posterior belly of omohyoid divides triangles Anterior Triangle Submandibular triangles - Boundaries: anterior and posterior bellies of digastric. - Contains: submandibular gland, facial artery and vein. Submental triangle - Boundaries: anterior belly of digastric - Contains: lymph nodes. Muscular triangles - Boundaries: omohyoid, sternocleidomastoid (SCM). - Contains: infrahyoid muscles Carotid triangles - Boundaries: omohyoid, stylohyoid, digastric, SCM. Contents listed is not Posterior Triangle Contents: - Subclavian artery - External jugular vein - Brachial plexus - CN XI - Cervical plexus Occipital triangle - Boundaries: SCM, trapezius and omohyoid. Supraclavicular triangle - Boundaries: clavicular head of SCM, clavicle and omohyoid Quiz Swelling of lymph nodes can be a sign of illness or infection. In which of the anterior triangles in the neck could this swelling be palpated? A. Carotid B. Muscular C. Occipital D. Subclavian E. Submental Quiz Swelling of lymph nodes can be a sign of illness or infection. In which of the anterior triangles in the neck could this swelling be palpated? A. Carotid B. Muscular C. Occipital D. Subclavian E. Submental Quiz Which muscle forms the boundary between the submental and submandibular triangles? A. Anterior belly of digastric B. Omohyoid C. Posterior belly of digastric D. Sternocleidomastoid E. Stylohyoid Quiz Which muscle forms the boundary between the submental and submandibular triangles? A. Anterior belly of digastric B. Omohyoid C. Posterior belly of digastric D. Sternocleidomastoid E. Stylohyoid Cervical Nerves Cervical plexus Roots of C1-C4 lie anterior to levator scapulae. Provides cutaneous branches and deep motor branches - Ansa cervicalis and phrenic nerve Brachial plexus Roots of C5-T1 emerge between anterior and middle scalene muscles. Supply cutaneous and motor innervation to the upper limb. Note: This slide is for information for future modules not for assessment in 202 Arterial Supply to the Neck - Brachiocephalic (right side) - Common carotid - Internal and external carotids - External carotid - Superior thyroid Ascending pharyngeal Lingual Facial Maxillary Superficial temporal - Subclavian arteries - Inferior thyroid - Internal carotid Venous Drainage of the Neck The Internal jugular vein (IJV) drains: - Brain - Face - Cervical viscera - Neck muscles External jugular vein - Formed from posterior auricular vein and the retromandibular vein - Drains: scalp, face, neck Anterior jugular vein - Variable and inconsistent The Accessory Nerve - CN XI Motor supply to: - Sternocleidomastoid - Trapezius Exits via Jugular foramen Allows shrugging shoulders movement Quiz Do veins in the head and neck have valves? A. Yes B. No C. Maybe D. It’s not my place to say E. ¯\_( ツ )_/¯ Quiz Do veins in the head and neck have valves? A. Yes B. No C. Maybe D. It’s not my place to say E. ¯\_( ツ )_/¯ Further Reading Gray’s Anatomy for Students - Ideal for diagrams and explanations McMinn’s and Abraham’s Clinical Atlas of Human Anatomy - Cadaveric image atlas - great DR prep Neuroanatomy - An Illustrated Colour Text - Concise neuroanatomy explanations with great diagrams However, if you have any questions, concerns or feedback, please feel free to get in touch: D.O’[email protected] or you can provide feedback anonymously through Qualtrics Dominic O’Brien - Qualtrics Feedback Survey A hole in the back-most fossa That two nerves, one art, pass through If tumour were to compress it Can’t walk straight, feel face, hear you. Internal Acoustic Meatus