Things to from BD CH#15 Page 26 CH 15, Page 255 Formation of Lateral wall of nose--- Lymphatic drainage of nasal cavityC-H--#- 15 page 255-256 Arterial supply, venous drainage, lymphatic drainage and ImpnoervteasnuptpSlyEofQpasranasal sinuses 1st priority Give the arterial supply of medal and lateral walls of nasal cavity. What are the components of bony part of nasal septum? Discuss the anatomical basis of epistaxis with reference to arterial supply of nasal septum. What are the boundaries of nasal cavities? What is the venous drainage, innervation and lymphatic nd 2 pdrraiionraigteyo;f nasal cavity? What is rhinitis? Enlist five different routes of spread of infection from nasal cavity. www.themedicalglobe.com / www.mgElearning.net Page 1 of 9 What is little’s area and what is its clinical importance? What is the skeleton of external nose? What are nasal meatus? Enumerate openings in various meatus. What are paranasal sinuses? briefly describe frontal sinus, ethmoidal and sphenoidal sinuses. What are boundaries of Maxillary sinus. Give its arterial supply, NOTEv;eDnoufsirasntdplryimorpihtyatSicEQdrSafiinrasgteaannddtihnennersveactoionnd priority SEQs. Do not skip any Imp clinicals Nasal fractures Rhinitis Impeopirstaaxnist points for MCQs and VIVA; Skeleton of the nose is composed of bone and hyaline cartilage. The bony part of the nose (consists of the nasal bones, frontal processes of the maxillae, the nasal part of the frontal bone and its nasal spine, and the bony parts of the nasal septum. The main components of the nasal septum are the perpendicular plate of the ethmoid, the vomer, and the septal cartilage roof of the nasal cavities is formed by frontonasal, ethmoidal, and sphenoidal bones www.themedicalglobe.com / www.mgElearning.net Page 2 of 9 The floor of the nasal cavities is formed by the palatine processes of the maxilla and the horizontal plates of the palatine bone. The medial wall of the nasal cavities is formed by the nasal septum. The lateral walls of the nasal cavities are irregular owing to three bony plates, the nasal conchae. The lateral wall of nasal cavities is formed by nasal, frontal process of maxilla, lacrimal, labyrinth of ethmoid with superior and middle concha, inferior nasal concha made of spongy bone and perpendicular plate of palatine bones together with its orbital and sphenoidal processes. Conchae are scroll-like structures that offer a vast surface area for heat exchange. The nasal cavity is thus divided into five passages: a posterosuperiorly placed spheno-ethmoidal recess, three laterally located nasal meatus (superior, middle, and inferior), and a medially placed common nasal meatus into which the four lateral passages open. The inferior concha is the longest and broadest of the conchae Inferior concha is formed by an independent bone (of the same name, inferior concha) covered by a mucous membrane that contains large vascular spaces that can enlarge to control the caliber of the nasal cavity. The middle and superior conchae are medial processes of the ethmoid bone. The spheno-ethmoidal recess, lying superoposterior to the superior concha, www.themedicalglobe.com / www.mgElearning.net Page 3 of 9 The spheno-ethmoidal recess, receives the opening of the sphenoidal sinus In superior nasal meatus ethmoidal sinuses open by one or more orifices The middle nasal meatus, the anterosuperior part of this passage leads into a funnel-shaped opening, the ethmoidal infundibulum, through which it communicates with the frontal sinus semilunar hiatus (L. hiatus semilunaris) is a semicircular groove into which the frontal sinus opens. The bulla is formed by middle ethmoidal cells that form the ethmoidal sinuses. The nasolacrimal duct, which drains tears from the lacrimal sac, opens into the anterior part of inferior nasal meatus. The common nasal meatus is the medial part of the nasal cavity between the conchae and the nasal septum, into which the lateral recesses and meatus open. The arterial supply of the medial and lateral walls of the nasal cavity is from five sources: Anterior ethmoidal artery (from the ophthalmic artery), Posterior ethmoidal artery (from the ophthalmic artery), Sphenopalatine artery (from the maxillary artery), Greater palatine artery (from the maxillary artery) and Septal branch of the superior labial artery (from the facial artery). anterior part of the nasal septum is the site of an anastomotic arterial plexus involving all five arteries supplying the septum (Kiesselbach area). www.themedicalglobe.com / www.mgElearning.net Page 4 of 9 The external nose receives blood from anterior ethmoidal, septal branch of superior labial artery, nasal branches of the infraorbital artery and the lateral nasal branches of the facial artery. A rich submucosal venous plexus, deep to the nasal mucosa, provides venous drainage of the nose via the sphenopalatine, facial, and ophthalmic veins. Venous blood from the external nose drains mostly into the facial vein via the angular and lateral nasal veins The nerve supply of the postero-inferior portion of the nasal mucosa is chiefly from the maxillary nerve, by way of the nasopalatine nerve to the nasal septum, and posterior superior lateral nasal and inferior lateral nasal branches of the greater palatine nerve to the lateral wall. The nerve supply of the anterosuperior portion of nasal mucosa is from the ophthalmic nerve (CN V1) by way of the anterior and posterior ethmoidal nerves, branches of the nasociliary nerve. Most of the external nose (dorsum and apex) is also supplied by CN V1 (via the infratrochlear nerve and the external nasal branch of the anterior ethmoidal nerve), the alae of the nose are supplied by the nasal branches of the infra-orbital nerve (CN V2). Lymphatics from anterior half of lateral wall pass to submandibular lymph nodes. Lymphatics from posterior half pass to retropharyngeal and upper deep cervical lymph nodes. www.themedicalglobe.com / www.mgElearning.net Page 5 of 9 The paranasal sinuses are air-filled extensions of the respiratory part of the nasal cavity into the following cranial bones: frontal, ethmoid, sphenoid, and maxilla. The right and left sinuses frontal sinus each drain through a frontonasal duct into the ethmoidal infundibulum, which opens into the semilunar hiatus of the middle nasal meatus. The frontal sinuses are supplied by supraorbital artery, venous drainage into supraorbiral and superior ophthalmic vein, lymphatic drainage into submandibular lymph nodes. innervated by branches of the supra-orbital nerves (CN V1). The anterior ethmoidal cells drain directly or indirectly into the middle nasal meatus through the ethmoidal infundibulum. The anterior and middle ethmoidal cells are supplied by anterior ethmoidal vessels and nerve, lymphatic drainage into submandibular lymph nodes. The middle ethmoidal cells open directly into the middle meatus and are sometimes called “bullar cells” because they form the ethmoidal bulla. The posterior ethmoidal cells open directly into the superior meatus. The posterior ethmoidal cells are supplied by posterior ethmoidal vessels and nerve, lymphatic drainage into retropharyngeal lymph nodes. sphenoidal sinuses that open separately into the sphenoethmoidal recess. The posterior ethmoidal vessels and the posterior ethmoidal nerves supply the sphenoidal sinuses, venous drainage into www.themedicalglobe.com / www.mgElearning.net Page 6 of 9 pterygoid venous plexus and lymphatic drainage into retropharyngeal lymph nodes. The maxillary sinuses are the largest of the paranasal sinuses. maxillary sinus drains by one or more openings, the maxillary ostium (ostia), into the middle nasal meatus of the nasal cavity by way of the semilunar hiatus. The arterial supply of the maxillary sinus is mainly from superior alveolar branches of the maxillary artery. Branches of the descending and greater palatine arteries supply the floor of the sinus. Innervation of the maxillary sinus is from the anterior, middle, and posterior superior alveolar nerves, which are branches of the maxillary nerve Venous drainage into facial vein and pterygoid venous plexus and lymphatic drainage into submandibular lymph nodes fractures of the nasal bones are common in automobile accidents and contact sports (unless face guards are worn). Fractures of nasal bones usually result in deformation of the nose, particularly when a lateral force is applied by someone’s elbow, In fractures of nasal bones, epistaxis (bleeding from the nose) usually occurs. In severe fractures, disruption of the bones and cartilages results in displacement of the nose. When the injury results from a direct blow, the cribriform plate of the ethmoid bone may also fracture. Epistaxis, In most cases, the cause is trauma and the bleeding is from an area in the anterior third of the nose (Kiesselbach area) because of the rich blood supply. www.themedicalglobe.com / www.mgElearning.net Page 7 of 9 Important figure for MCQs, SEQs and VIVA 7.102 7.105 7.106 Copyright: Medical Globe 2020 www.themedicalglobe.com / www.mgElearning.net Page 8 of 9 www.themedicalglobe.com / www.mgElearning.net Page 9 of 9.