Nasal Cavity Flashcards
External nose
Varies in shape/size mostly due to nasal cartilage. 2 nostrils, also known as nares.
Roof of nose
Contents include: cribiform plate of the ethmoid bone, nasal bones, maxilla, frontal bones, and nasal cartilage
Nasal septum
Separates left and right airways of nose/divides the two nostrils. Comprised of the vomer, the perpendicular plate of the ethmoid, and septal cartilage and meets with the palatine and maxillary bones at the bottom.
Floor of the Nose
Floor of the nasal cavity forms the roof of the mouth. Comprised of the hard palate, palatine process of the maxilla (point of articulation between maxilla and palatine), and palatine bone. The incisive foramen, greater palatine foramen, and lesser foramen can be found here, along with their contents [Incisive foramen:nasopalatine nerve & sphenopalatine artery, greater palatine foramen: greater palatine nerve, lesser palatine foramen: lesser palatine nerve]
Lateral Wall of Nasal Cavity
Comprised of a series of conchae (KUUNNKKAAAA!!!) and meatuses (spaces below each concha). Conchae are long, narrow, curved bones that force air to flow in a regular pattern around an increased surface area of cilia and temperature increased tissue. Conchae of the nasal cavity are the inferior concha (considered a separate bone), the middle concha (part of the ethmoid), and the superior concha (also part of the ethmoid). Meatuses of the nasal cavity are the inferior, middle, and superior meatuses.
Arterial Supply to Nasal Cavity
Anterior ethmoidal artery, Posterior ethmoidal artery, Sphenopalatine artery, greater palatine artery, superior labial artery
Anterior Ethmoidal Artery
Branches from opthalmic artery to supply anterior and ethmoid air cells, frontal sinus, and anterosuperior aspect of nasal wall
Posterior ethmoidal artery
Branches from opthalmic artery; enters posterior ethmoidal canal. Exits into nasal cavity to supply posterior ethmoidal air cells and nasal septum. Anastomoses with sphenopalatine artery.
Sphenopalatine artery
Branch of the maxillary artery. Passes through sphenopalatine foramen to enter the nasal cavity. Gives off posterior septal branches which anastomose with anterior ethmoidal, posterior ethmoidal, and palatine arteries.
Greater palatine artery
A terminal branch of the maxillary artery. Supplies blood to the hard palate and nasal septum. Enters through the greater palatine foramen. Eventually anastomoses with the sphenopalatine artery in its course to supply the nasal septum
Superior labial artery
Runs along upper lip to supply blood to (duh) upper lip. Gives off vessels which ascend to the nose, including a septal branch to give off to the septum. Anastomoses with superior labial artery on the other side.
Venous drainage of the nasal cavity
Rich submucousal plexus (pterygoid plexus) drains into sphenopalatinal vein, facial vein, and opthalmic vein
Sphenopalatine vein
Drains into the maxillary vein
Facial vein
Starts at the nose, receives blood from external palatine, drains into retromandibular vein. Fun fact: Dr. Khan says that it has no valves but recent literature says that this isn’t true.
Opthalamic veins
Superior and inferior veins exist. Join pterygoid plexus.
Nerves of the nasal cavity
CNI, Nasopalatine, Greater palatine, lesser palatine, ptyergopalatine ganglion,
CNI
Olfactory nerve. Provides special sensation (smell) to the olfactory mucosa
Nasopalatine Nerve
Branch of the maxillary nerve. Sensory to the nasal septum and anterior part of the hard palate.
Greater Palatine Nerve
From the maxillary nerve (branch of CNV). Sensory to Hard palate
Lesser Palatine Nerve
From the maxillary nerve (branch of CNV). Sensory to Soft Palate
Pterygopalatine ganglion
Parasympathetic ganglion. Branches of the maxillary nerve pass through this ganglion; ptyergoganglionic parasympathetic fibers from CN VII terminate here.
Paranasal Sinuses
Air filled chambers that communicate with the nose. Act as resonating chambers for sound quality. Located in the frontal, maxilla, sphenoid, and ethmoid bones. Each have individual openings that allow sinuses to drain into the nasal cavity. Absent in newborns; develop after birth. Fronal sinuses (2), maxillary sinus (1), sphenoid sinuses (2), and ethmoidal air sinuses (many! 3-18).
Frontal Sinus
- Located in the frontal bone. Duct drains into the middle meatus (part of the ethmoid bone)
Maxillary sinus
- Located in the maxilla. Opens at the hiatus semiluminaris of the middle meatus (part of the ethmoid bone). Most commonly infected of the sinuses: opening of the sinus is small and located on the superior part of the sinus, making it difficult for the sinus to drain. When the mucus membrane of the sinus is congested, it blocks the opening.
Sphenoid sinus
- Located in the sphenoid bone. Open in the sphenoethmoidal recess, a region above the superior concha (once again, ethmoid bone) and between the sphenoid and ethmoid.
Ethmoid air cells
Located in the ethmoid bone. Honey comb apperance. 3-18 in number. Arranged in three groups: anterior, middle, and posterior. Anterior and middle groups open into the middle meatus (ethmoid bone). Posterior group open into superior meatus (ethmoid bone)
